RE: [beagleboard] Re: VGA camera capture

[Matthew Witherwax]

Looks like framegrabber was able to capture images based on the output you 
provided. Did you look at the images?

If it works for you then the code for the subscriber here 
http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming will show you how to load 
it into opencv.

-Original Message-
From: "João M. S. Silva" 
Sent: ‎5/‎25/‎2016 4:13 PM
To: "beagleboard@googlegroups.com" 
Subject: Re: [beagleboard] Re: VGA camera capture

If the camera has a good compression mechanism (e.g. MJPEG), it may be 
softer on the USB bus.

In our board, we are using OpenCV but we don't capture images with the 
OpenCV instruction. Instead, we use something like this:

https://linuxtv.org/downloads/v4l-dvb-apis/v4l2grab-example.html

For video capturing there is also an example:

https://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html

Note that OpenCV uses v4l underneath.

On 25/05/2016 16:51, Tinashe Mudavanhu wrote:
> Silva,
>
> There has to be way. Dereck Molloy
> https://www.youtube.com/watch?v=8QouvYMfmQo was able to get a video
> stream then its possible to video stream with BBB. I don't have much
> time to look for another development board because the Project is due
> next week.
>
> On Wed, May 25, 2016 at 5:48 PM, Tinashe Mudavanhu  <mailto:tinam...@gmail.com>> wrote:
>
> Hi,
>
> The same is happening on the other webcam i have (not sure if its
> openCV changing resolution). I bought it on AliExpress and has the
> following discription; HD 1.3 megapixel 960p 2.8-12mm varifocal lens
> Aptina AR0130 android external usb camera module with IR cut
> ELP-USB130W01MT-FV
> 
> <http://www.aliexpress.com/item/HD-1-3-megapixel-2-8-12mm-varifocal-lens-android-external-usb-camera-module-with-IR/32295825258.html>.
> The supplier can be found on http://www.elpcctv.com.
>
> Since there are no errors, what could be the problem? Is there some
> dependencies i have to install?
>
> I tested with your framebrabber.c code and was getting this (see
> below) with the Logitech webcam,
>
> root@beaglebone:~# time ./framegrabber -f mjpeg -H 480 -W 640 -c
> 1000 -I 30
> Startup took 0.01 seconds
> Captured 1000 frames in 0.22 seconds
> Shutdown took 0.00 seconds
>
>
> real0m42.068s
> user0m0.025s
> sys0m0.223s
>
> The no name webcam was giving the following results;
> root@beaglebone:~# time ./framegrabber -f mjpeg -H 480 -W 640 -c
> 1000 -I 30
> Startup took 0.02 seconds
> Captured 1000 frames in 0.26 seconds
>     Shutdown took 0.00 seconds
>
>
> real2m10.965s
> user0m0.033s
> sys0m0.262s
> root@beaglebone:~#
>
>
>
> On Wed, May 25, 2016 at 5:23 PM, Matthew Witherwax
> mailto:ablec...@gmail.com>> wrote:
>
> There are no actual errors in the output you posted.
>
> Do you have access to any other webcams?  I have tested this
> with the Logitech C920, the Logitech C270, and the PS3Eye.
> Without access to your webcam, it is hard for me to look into
> what is going on.
>
>
> On Wednesday, May 25, 2016 at 8:57:55 AM UTC-5, Tinashe
> Mudavanhu wrote:
>
> The timeout error resurfaced again, i followed you blog post
> on
> http://blog.lemoneerlabs.com/3rdParty/Darling_BBB_30fps_DRAFT.html
> but got the following errors in compiling libjpeg-turbo ;
>
> root@beaglebone:~/libjpeg-turbo-1.3.0/build# make
> make  all-recursive
> make[1]: Entering directory `/root/libjpeg-turbo-1.3.0/build'
> Making all in java
> make[2]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/java'
> make[2]: Nothing to be done for `all'.
> make[2]: Leaving directory
> `/root/libjpeg-turbo-1.3.0/build/java'
> Making all in simd
> make[2]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> make  all-am
> make[3]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> make[3]: Nothing to be done for `all-am'.
> make[3]: Leaving directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> make[2]: Leaving directory
> `/root/libjpeg-turbo-1.3.0/build/simd'
> Making all in md5
> make[2]: Entering directory
> `/root/libjpeg-turbo-1.3.0/build/md5'
> make[2]: Nothing to be done for `all'.
> mak

Re: [beagleboard] Re: VGA camera capture

[Matthew Witherwax]

There are no actual errors in the output you posted.

Do you have access to any other webcams?  I have tested this with the 
Logitech C920, the Logitech C270, and the PS3Eye.  Without access to your 
webcam, it is hard for me to look into what is going on.

On Wednesday, May 25, 2016 at 8:57:55 AM UTC-5, Tinashe Mudavanhu wrote:
>
> The timeout error resurfaced again, i followed you blog post on  
> http://blog.lemoneerlabs.com/3rdParty/Darling_BBB_30fps_DRAFT.html but 
> got the following errors in compiling libjpeg-turbo ;
>
> root@beaglebone:~/libjpeg-turbo-1.3.0/build# make
> make  all-recursive
> make[1]: Entering directory `/root/libjpeg-turbo-1.3.0/build'
> Making all in java
> make[2]: Entering directory `/root/libjpeg-turbo-1.3.0/build/java'
> make[2]: Nothing to be done for `all'.
> make[2]: Leaving directory `/root/libjpeg-turbo-1.3.0/build/java'
> Making all in simd
> make[2]: Entering directory `/root/libjpeg-turbo-1.3.0/build/simd'
> make  all-am
> make[3]: Entering directory `/root/libjpeg-turbo-1.3.0/build/simd'
> make[3]: Nothing to be done for `all-am'.
> make[3]: Leaving directory `/root/libjpeg-turbo-1.3.0/build/simd'
> make[2]: Leaving directory `/root/libjpeg-turbo-1.3.0/build/simd'
> Making all in md5
> make[2]: Entering directory `/root/libjpeg-turbo-1.3.0/build/md5'
> make[2]: Nothing to be done for `all'.
> make[2]: Leaving directory `/root/libjpeg-turbo-1.3.0/build/md5'
> make[2]: Entering directory `/root/libjpeg-turbo-1.3.0/build'
> make[2]: Leaving directory `/root/libjpeg-turbo-1.3.0/build'
> make[1]: Leaving directory `/root/libjpeg-turbo-1.3.0/build'
> root@beaglebone:~/libjpeg-turbo-1.3.0/build# 
>
>
> Before compiling libjpeg-turbo i tested my code to see what will be 
> happening on the resolution and frame rate. I am working with a Logitech 
> QuickCam E3500 which has support for both YUVY and MJPEG. I set the 
> resolution to 320x240 with a 30fps frame rate but after running the code, 
> got select timeout errors and the resolution had changed to 640x480 YUVY 
> with a 15fps frame rate;
>
> root@beaglebone:~/libjpeg-turbo-1.3.0/build# v4l2-ctl -V
> Format Video Capture:
> Width/Height  : 640/480
> Pixel Format  : 'YUYV'
> Field : None
> Bytes per Line: 1280
> Size Image: 614400
> Colorspace: SRGB
> root@beaglebone:~/libjpeg-turbo-1.3.0/build# 
>
>
>
>
> On Tue, May 24, 2016 at 1:22 AM, Tinashe Mudavanhu  > wrote:
>
>> Hi Matthew,
>>
>> I'm a rookie in this linux/opencv area i wouldn't really know what it 
>> means, only learning from you. I posted a question 
>> https://groups.google.com/forum/#!category-topic/beagleboard/debian/VFuvveM_8Gc
>>  
>> looking for a solution because it always happened when i plugged in the 
>> webcam on BBB. Running the command i previously mentioned ended my woes.
>>
>> On Tue, May 24, 2016 at 1:04 AM, Matthew Witherwax > > wrote:
>>
>>> The issue causing the select time out detailed in my article has to do 
>>> with how much data is being sent over the USB and how it is sent. Reducing 
>>> the frame rate reduces the load on the USB. Looking at the articles you 
>>> linked, one says it solved an issue but not the select timeout, and the 
>>> other shows an error message that says it could not allocate memory.  
>>> Neither one of these are the cause of the select timeout I addressed. 
>>>
>>> The select timeout occurs when the select times out. Looks like in the 
>>> cases in your links a previous call to allocate memory failed followed by 
>>> select failing. I have never had an issue with memory allocation. All my 
>>> troubles had to do with too much data on the USB. You might want to confirm 
>>> what your actual problem is. 
>>> --
>>> From: Tinashe Mudavanhu 
>>> Sent: ‎5/‎23/‎2016 4:58 PM
>>> To: beagl...@googlegroups.com 
>>> Subject: Re: [beagleboard] Re: VGA camera capture
>>>
>>> Hi Matthew,
>>>
>>> I looked into the article as i went through your discussion but did not 
>>> try the framegrabber.c, will test it though. I finally got a solution to 
>>> the problem from links listed below. It kind of made sense to me (lack of 
>>> memory in ARM systems) because running the same code on my PC worked 
>>> perfectly well. Running this command `sysctl vm.overcommit_memory=1` worked 
>>> for me after a long struggle. What i'm not really sure are the implications 
>>> (being it on Hardware or Software) if 

RE: [beagleboard] Re: VGA camera capture

[Matthew Witherwax]

The issue causing the select time out detailed in my article has to do with how 
much data is being sent over the USB and how it is sent. Reducing the frame 
rate reduces the load on the USB. Looking at the articles you linked, one says 
it solved an issue but not the select timeout, and the other shows an error 
message that says it could not allocate memory.  Neither one of these are the 
cause of the select timeout I addressed. 

The select timeout occurs when the select times out. Looks like in the cases in 
your links a previous call to allocate memory failed followed by select 
failing. I have never had an issue with memory allocation. All my troubles had 
to do with too much data on the USB. You might want to confirm what your actual 
problem is. 

-Original Message-
From: "Tinashe Mudavanhu" 
Sent: ‎5/‎23/‎2016 4:58 PM
To: "beagleboard@googlegroups.com" 
Subject: Re: [beagleboard] Re: VGA camera capture

Hi Matthew,

I looked into the article as i went through your discussion but did not try the 
framegrabber.c, will test it though. I finally got a solution to the problem 
from links listed below. It kind of made sense to me (lack of memory in ARM 
systems) because running the same code on my PC worked perfectly well. Running 
this command `sysctl vm.overcommit_memory=1` worked for me after a long 
struggle. What i'm not really sure are the implications (being it on Hardware 
or Software) if there comes a state when large size memory is really needed.


  [1]: https://www.raspberrypi.org/forums/viewtopic.php?f=31&t=17773
  [2]: 
https://tequals0.wordpress.com/2014/03/24/libv4l2-error-allocation-conversion-buffer-using-opencv-on-a-pi/



On Mon, May 23, 2016 at 10:25 PM, Matthew Witherwax  wrote:

Hi Tinashe,


Please see my article here http://blog.lemoneerlabs.com/post/BBB-webcams

There is a version of framegrabber.c linked to it that allows you to specify 
the frame rate with the command line parameter -I.  If reducing the frame rate 
works for you, then the code for framegrabber should provide a starting point 
for accomplishing the same thing in your own program.



On Mon, May 23, 2016 at 2:43 PM, Tinashe Mudavanhu  wrote:

Firstly i would like to say i came across your discussion looking for select 
timeout error solution but as i went through it i didnt notice if you found a 
solution, but if you have it now, i would appreciate it. The select timeout 
error still seems to be in existence even on BBB Rev C with kernel  
3.8.13-bone79. I am working on an Iris recognition system that initially has to 
track eyes in a live video stream (from there captures cropped eye images that 
will be processed). I have installed different OpenCV versions, 2.4.9, 2.4.11 
and 3.0.0 and in all of them i am getting the same error. I am working with a 
Logitech, Inc. QuickCam E 3500 webcam. I am accessing the BBB Desktop using 
Tightvnc client on my PC running Ubuntu 14.04 LTS.

What is surprising is that it is capable of video streaming with opencv 
installed by apt-get (apt-get install python-opencv) but the limitation with 
this version is that it has very old cv bindings and documentation on some 
functions for Histogram equalisation is not available online. I am stuck, i 
need your help. 

On Tuesday, 10 September 2013 16:50:46 UTC+2, Matthew Witherwax wrote:
Getting another BBB or raspberry pi probably wont help, but a U2 from 
HardKernel here 
http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G135341370451
 probably would.  You can use the BBB to do all IO and use the processing power 
of the U2 to handle compute intensive tasks.  That is actually my end goal.  
The cpu use I stated earlier was without showing the image.  Displaying the 
image will increase cpu use.

I am also working on a tracking application with the webcam mounted on a servo. 
 For my purposes, I do not need to see the image on the BBB and can push it 
over wifi to my laptop if I want to view it.


As far as cv code, what are you looking for?  I have posted a tool on my blog 
here http://blog.lemoneerlabs.com/post/shades-of-red to help you find HSV 
values from images to allow you to to find values to threshold target colors.  
I will post another one on using HSV ranges to threshold an image to isolate 
things like a red colored ball.  I have been implementing OpenCV code using 
python right now for experimentation, but you should be able to translate it to 
C++ or your language of choice.


The command v4l2-ctl --list-formats-ext will tell you the pixel formats and 
resolutions supported by your camera.


Hope this helps,


Matthew Witherwax




On Tue, Sep 10, 2013 at 8:48 AM, James Richins  wrote:

Matthew,


It does remind of something on Derek Molloy's site in that he adds coding to 
deal with the h264 codec for taking stills with opencv. I hesitated at the 
idea. Interestingly even using an additional bbb or raspberry pi might not even 
help. I'm looking at cam

Re: [beagleboard] Re: VGA camera capture

[Matthew Witherwax]

Hi Tinashe,

Please see my article here http://blog.lemoneerlabs.com/post/BBB-webcams
There is a version of framegrabber.c linked to it that allows you to
specify the frame rate with the command line parameter -I.  If reducing the
frame rate works for you, then the code for framegrabber should provide a
starting point for accomplishing the same thing in your own program.

On Mon, May 23, 2016 at 2:43 PM, Tinashe Mudavanhu 
wrote:

> Firstly i would like to say i came across your discussion looking for
> select timeout error solution but as i went through it i didnt notice if
> you found a solution, but if you have it now, i would appreciate it. The
> select timeout error still seems to be in existence even on BBB Rev C with
> kernel  3.8.13-bone79. I am working on an Iris recognition system that
> initially has to track eyes in a live video stream (from there captures
> cropped eye images that will be processed). I have installed different
> OpenCV versions, 2.4.9, 2.4.11 and 3.0.0 and in all of them i am getting
> the same error. I am working with a Logitech, Inc. QuickCam E 3500 webcam.
> I am accessing the BBB Desktop using Tightvnc client on my PC running
> Ubuntu 14.04 LTS.
>
> What is surprising is that it is capable of video streaming with opencv
> installed by apt-get (apt-get install python-opencv) but the limitation
> with this version is that it has very old cv bindings and documentation on
> some functions for Histogram equalisation is not available online. I am
> stuck, i need your help.
>
> On Tuesday, 10 September 2013 16:50:46 UTC+2, Matthew Witherwax wrote:
>>
>> Getting another BBB or raspberry pi probably wont help, but a U2 from
>> HardKernel here
>> http://www.hardkernel.com/renewal_2011/products/prdt_info.php?g_code=G135341370451
>> probably would.  You can use the BBB to do all IO and use the processing
>> power of the U2 to handle compute intensive tasks.  That is actually my end
>> goal.  The cpu use I stated earlier was without showing the image.
>> Displaying the image will increase cpu use.
>>
>> I am also working on a tracking application with the webcam mounted on a
>> servo.  For my purposes, I do not need to see the image on the BBB and can
>> push it over wifi to my laptop if I want to view it.
>>
>> As far as cv code, what are you looking for?  I have posted a tool on my
>> blog here http://blog.lemoneerlabs.com/post/shades-of-red to help you
>> find HSV values from images to allow you to to find values to threshold
>> target colors.  I will post another one on using HSV ranges to threshold an
>> image to isolate things like a red colored ball.  I have been implementing
>> OpenCV code using python right now for experimentation, but you should be
>> able to translate it to C++ or your language of choice.
>>
>> The command v4l2-ctl --list-formats-ext will tell you the pixel formats
>> and resolutions supported by your camera.
>>
>> Hope this helps,
>>
>> Matthew Witherwax
>>
>>
>> On Tue, Sep 10, 2013 at 8:48 AM, James Richins 
>> wrote:
>>
>>> Matthew,
>>>
>>> It does remind of something on Derek Molloy's site in that he adds
>>> coding to deal with the h264 codec for taking stills with opencv. I
>>> hesitated at the idea. Interestingly even using an additional bbb or
>>> raspberry pi might not even help. I'm looking at camera tracking
>>> objects/object recognition and servo control.
>>> I might find that by not displaying the video on the monitor, that the
>>> tracking and servo control can work less than 100% CPU.
>>> I have yet to implement the cv code for that, it's a real struggle to
>>> find good code. And not get errors. I have managed servo control through
>>> python and manual entering numbers so its ultimately possible.
>>> I'm not sure if my camera does anything other than yuyv. I'd be
>>> interested in connecting an Ethernet cam to the Ethernet port and read
>>> camera data from there, but you'd probably run into the same problem.
>>> Ethernet cam to pc processing cv code, wifi to beaglebone servo control
>>> might be good. But its probably a slow process and too complicated for me.
>>>
>>> Anyway good luck with your project.
>>>
>>> James
>>>
>>> On 10 Sep 2013, at 13:57, Matthew Witherwax  wrote:
>>>
>>> James,
>>>
>>> I have not done any cpu testing other than while saving single frames.
>>> In MJPEG format, capturing a single frame at 1920x1080 30 fps and saving it
>>> was taking about 6% cpu.  Doing the same in YUYV at a red

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Adam,

If your issue is a low frame rate coming from the PS3Eye, I have written
about this problem here http://blog.lemoneerlabs.com/post/BBB-webcams
To make a long story short, the transfer method the PS3Eye uses to transfer
data over USB doesn't work on the BBB at high frame rates and/or high
resolutions.

If the frame rate you are getting is sufficient, then the question becomes,
what algorithm is being used to track faces?

Let me know what is going on, and I will help where I can.

Matthew


On Mon, Mar 31, 2014 at 4:50 AM,  wrote:

> Hi all,
>
> I worked on this project a while back - www.ben-dror.com/pinokio I want
> to get it running on a beagle bone.
> I have purchased a BBB and a ps3 eye. OpenCV face-tracking seems to run at
> a very low frame-rate. I guess I am looking for around 15fps.
> Please any insights would be greatly appreciated.
>
> Adam
>
>
> On Wednesday, February 19, 2014 9:03:43 AM UTC+13, Michael Darling wrote:
>
>> Glad I could help.  =]   Let me know what you find out after looking into
>> it a little bit more!
>>
>>
>> On Tue, Feb 18, 2014 at 11:31 AM,  wrote:
>>
>>> you are absolutely right. at 1280x720 it is limited to 10 fps in YUYV
>>> format and i do get about 26fps in 640x480, but that could be just how fps
>>> are calculated. so it could be 30 in reality.
>>>
>>> thank you.
>>>
>>>
>>> On Tuesday, February 18, 2014 2:12:16 PM UTC-5, Michael Darling wrote:
>>>
>>>> My first question for you would be which pixel format are you capturing
>>>> in?  If you do a "v4l2-ctl -d /dev/videoX --list-formats-ext" in the
>>>> command line (where X is 0, 1, ...  whatever your C920 is) you can see the
>>>> various pixel formats, resolutions, and frame rates supported by the 
>>>> camera.
>>>>
>>>> For YUYV, the maximum frame rate at 1280x720 is 10 fps.  If you are
>>>> using H.264 or MJPEG, the maximum frame rate is 30 fps.
>>>>
>>>> I'm doubtful that that's your problem since you are still only getting
>>>> 15 fps at lower resolutions.  (Can you get 30 fps at 640x480?  That is the
>>>> resolution I am using for my own project and might serve as a good baseline
>>>> measurement.)
>>>>
>>>> My only other thought for now is that your actual measurement of the
>>>> frame rate could be wrong.  I don't have much experience with pthreads, but
>>>> I know that some of the "clock" functions in the  header have to be
>>>> handled differently when you are multi-threading.
>>>>
>>>> Those are my only ideas for now.  I'll keep racking my brain and let
>>>> you know if I come up with something else.
>>>>
>>>> - Mike
>>>>
>>>>
>>>>  On Sun, Feb 16, 2014 at 10:57 AM,  wrote:
>>>>
>>>>> Hello, ive been reading through the group and found i have found it
>>>>> very helpful. i am running an odroid u2 with ubuntu 12.11 and opencv
>>>>> 2.4.6.1.
>>>>> i used the code i found in git 
>>>>> :/mdarling39/<https://github.com/mdarling39/LinuxVision/blob/master/OCVCapture.cpp>to
>>>>>  capture from a logitech c920. i ran into an issue when i set the
>>>>> resolution to 1280*720 the fps would not go past 10. however for any
>>>>> smaller resolution i am able to get 15 fps no problem. the custom capture
>>>>> code certainly does use less resources than the built in opencv function. 
>>>>> i
>>>>> have 2 threads, the main for capturing and the second for processing both
>>>>> of which do not max out their cpu so i cant figure out why im getting this
>>>>> fps drop.
>>>>>
>>>>>
>>>>> any help would be appreciated.
>>>>>
>>>>> Thanks
>>>>>
>>>>> On Thursday, January 30, 2014 3:17:40 PM UTC-5, Matthew Witherwax
>>>>> wrote:
>>>>>
>>>>>> If you bypass OpenCV and capture directly like we did, you should
>>>>>> test to see if you can capture successfully in YUYV format.  OpenCV can
>>>>>> convert YUYV to a Mat with less than 3% cpu use.  If you capture in 
>>>>>> MJPEG,
>>>>>> you will see cpu use of 90% or more to convert the image to a Mat.  This
>>>>>> isn't so bad on the Wandboard because it only consumes one core, but can 
>>>>>> be
>>&g

RE: [beagleboard] When to power sensors connected to the BeagleBoneBlack?

[Matthew Witherwax]

There is hope for us yet!

-Original Message-
From: "Gerald Coley" 
Sent: ‎3/‎6/‎2014 10:45 AM
To: "beagleboard@googlegroups.com" 
Subject: Re: [beagleboard] When to power sensors connected to the 
BeagleBoneBlack?

But now you have Nolan Ryan.



On Thu, Mar 6, 2014 at 10:36 AM, Matthew Witherwax  wrote:

I sure hope that was years ago when they actually won a game or two.  We have 
other attractions.  We even almost have NASA.


On Thursday, March 6, 2014 9:57:57 AM UTC-6, Gerald wrote:
Houston! Us folks in this part of the state try to stay away from Houston!


Actually I have spent a lot of time over the years in Houston. Been to a few 
Astros games as well. 





Gerald





On Thu, Mar 6, 2014 at 9:55 AM, Matthew Witherwax  wrote:

Next time you are in Houston, coffee is on me!


On Thursday, March 6, 2014 9:28:06 AM UTC-6, Gerald wrote:
That is my secret. I don't need coffee! The inside story is that I am always 
here. I have no life!


Gerald





On Thu, Mar 6, 2014 at 9:25 AM, Eric Palmer  wrote:

Yes I get that.  



On Thu, Mar 6, 2014 at 10:14 AM, Gerald Coley  wrote:

I am not sure how to take that!Not sure if it is luck or something else.


Gerald





On Thu, Mar 6, 2014 at 9:12 AM, Eric Palmer  wrote:

Awesome


Gerald we are lucky to have you on this mail list and be participating so much.


Thanks



On Thu, Mar 6, 2014 at 10:09 AM, Gerald Coley  wrote:

Yes you can do that  Use the 3.3V to enable the regulators.


Gerald





On Thu, Mar 6, 2014 at 9:03 AM, Matthew Witherwax  wrote:

Thanks Gerald.  That is exactly the response I was expecting and exactly the 
feeling I had.  Never really like playing Russian roulette myself.  Do you see 
any issue with powering the sensors via a voltage regulator like 
http://www.pololu.com/product/2098 that can be turned on via a pin on the BBB 
once it is up and running?




On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley  wrote:

I put that in there for a reason. It may not happen all the time, but 
eventually you could blow up the processor.


Gerald



On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax  wrote:

As part of the Control of Mobile Robotics class offered through Cousera, the 
students are building robots based around the BeagleBone Black.  The robot has 
5 infrared distance sensors and 2 reflectance sensors used for odometry.  These 
sensors are connected via voltage dividers to pins 33, 35, 36, 37, 38, 39, and 
49 of P9, and are powered from the same power supply used to power the 
BeagleBone Black.  The System Manual has a rather explicit warning:

NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO THE 
BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.

My concern is the current arrangement would allow the sensors to begin driving 
the pins before the SYS_RESET line goes high; however, I am a software guy just 
starting down the hardware path.  Thus far many in the class have been using 
the robot without issue.  Is my concern invalid?

Thank you for your time.

-- 
For more options, visit http://beagleboard.org/discuss
--- 

You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.

To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.



-- 
For more options, visit http://beagleboard.org/discuss
--- 

You received this message because you are subscribed to a topic in the Google 
Groups "BeagleBoard" group.
To unsubscribe from this topic, visit 
https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe.

To unsubscribe from this group and all its topics, send an email to 
beagleboard...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.



-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.

To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.



-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.

To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard...@googlegroups.com.

For more options, visit https://groups.google.com/groups/opt_out.






-- 

Eric Palmer
-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.

To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard...@googlegroups.com.

For more options, visit ht

Re: [beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

I sure hope that was years ago when they actually won a game or two.  We 
have other attractions.  We even almost have NASA.

On Thursday, March 6, 2014 9:57:57 AM UTC-6, Gerald wrote:
>
> Houston! Us folks in this part of the state try to stay away from Houston!
>
> Actually I have spent a lot of time over the years in Houston. Been to a 
> few Astros games as well. 
>
>
> Gerald
>
>
>
> On Thu, Mar 6, 2014 at 9:55 AM, Matthew Witherwax 
> 
> > wrote:
>
>> Next time you are in Houston, coffee is on me!
>>
>>
>> On Thursday, March 6, 2014 9:28:06 AM UTC-6, Gerald wrote:
>>
>>> That is my secret. I don't need coffee! The inside story is that I am 
>>> always here. I have no life!
>>>
>>> Gerald
>>>
>>>
>>>
>>> On Thu, Mar 6, 2014 at 9:25 AM, Eric Palmer wrote:
>>>
>>>> Yes I get that.  
>>>>
>>>>
>>>> On Thu, Mar 6, 2014 at 10:14 AM, Gerald Coley 
>>>> wrote:
>>>>
>>>>> I am not sure how to take that!Not sure if it is luck 
>>>>> or something else.
>>>>>
>>>>> Gerald
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Mar 6, 2014 at 9:12 AM, Eric Palmer wrote:
>>>>>
>>>>>> Awesome
>>>>>>
>>>>>> Gerald we are lucky to have you on this mail list and be 
>>>>>> participating so much.
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>>
>>>>>> On Thu, Mar 6, 2014 at 10:09 AM, Gerald Coley >>>>> > wrote:
>>>>>>
>>>>>>>  Yes you can do that  Use the 3.3V to enable the regulators.
>>>>>>>
>>>>>>> Gerald
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Mar 6, 2014 at 9:03 AM, Matthew Witherwax >>>>>> > wrote:
>>>>>>>
>>>>>>>> Thanks Gerald.  That is exactly the response I was expecting and 
>>>>>>>> exactly the feeling I had.  Never really like playing Russian roulette 
>>>>>>>> myself.  Do you see any issue with powering the sensors via a voltage 
>>>>>>>> regulator like http://www.pololu.com/product/2098 that can be 
>>>>>>>> turned on via a pin on the BBB once it is up and running?
>>>>>>>>
>>>>>>>>
>>>>>>>> On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley <
>>>>>>>> ger...@beagleboard.org> wrote:
>>>>>>>>
>>>>>>>>> I put that in there for a reason. It may not happen all the time, 
>>>>>>>>> but eventually you could blow up the processor.
>>>>>>>>>
>>>>>>>>> Gerald
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax <
>>>>>>>>> able...@gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>>  As part of the Control of Mobile Robotics class offered through 
>>>>>>>>>> Cousera, the students are building robots based around the 
>>>>>>>>>> BeagleBone 
>>>>>>>>>> Black.  The robot has 5 infrared distance sensors and 2 reflectance 
>>>>>>>>>> sensors 
>>>>>>>>>> used for odometry.  These sensors are connected via voltage dividers 
>>>>>>>>>> to 
>>>>>>>>>> pins 33, 35, 36, 37, 38, 39, and 49 of P9, and are powered from the 
>>>>>>>>>> same 
>>>>>>>>>> power supply used to power the BeagleBone Black.  The System Manual 
>>>>>>>>>> has a 
>>>>>>>>>> rather explicit warning:
>>>>>>>>>>
>>>>>>>>>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT 
>>>>>>>>>> SUPPLIED TO THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE 
>>>>>>>>>> WARRANTY.
>>>>>>>>>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.
>>>>>>>>>>
>>>>>>>>>> My concern is the

Re: [beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

Next time you are in Houston, coffee is on me!

On Thursday, March 6, 2014 9:28:06 AM UTC-6, Gerald wrote:
>
> That is my secret. I don't need coffee! The inside story is that I am 
> always here. I have no life!
>
> Gerald
>
>
>
> On Thu, Mar 6, 2014 at 9:25 AM, Eric Palmer 
> 
> > wrote:
>
>> Yes I get that.  
>>
>>
>> On Thu, Mar 6, 2014 at 10:14 AM, Gerald Coley 
>> 
>> > wrote:
>>
>>> I am not sure how to take that!Not sure if it is luck or something else.
>>>
>>> Gerald
>>>
>>>
>>>
>>> On Thu, Mar 6, 2014 at 9:12 AM, Eric Palmer 
>>> 
>>> > wrote:
>>>
>>>> Awesome
>>>>
>>>> Gerald we are lucky to have you on this mail list and be participating 
>>>> so much.
>>>>
>>>> Thanks
>>>>
>>>>
>>>> On Thu, Mar 6, 2014 at 10:09 AM, Gerald Coley 
>>>> 
>>>> > wrote:
>>>>
>>>>> Yes you can do that  Use the 3.3V to enable the regulators.
>>>>>
>>>>> Gerald
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Mar 6, 2014 at 9:03 AM, Matthew Witherwax 
>>>>> 
>>>>> > wrote:
>>>>>
>>>>>> Thanks Gerald.  That is exactly the response I was expecting and 
>>>>>> exactly the feeling I had.  Never really like playing Russian roulette 
>>>>>> myself.  Do you see any issue with powering the sensors via a voltage 
>>>>>> regulator like http://www.pololu.com/product/2098 that can be turned 
>>>>>> on via a pin on the BBB once it is up and running?
>>>>>>
>>>>>>
>>>>>> On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley 
>>>>>> 
>>>>>> > wrote:
>>>>>>
>>>>>>> I put that in there for a reason. It may not happen all the time, 
>>>>>>> but eventually you could blow up the processor.
>>>>>>>
>>>>>>> Gerald
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax 
>>>>>>> 
>>>>>>> > wrote:
>>>>>>>
>>>>>>>>  As part of the Control of Mobile Robotics class offered through 
>>>>>>>> Cousera, the students are building robots based around the BeagleBone 
>>>>>>>> Black.  The robot has 5 infrared distance sensors and 2 reflectance 
>>>>>>>> sensors 
>>>>>>>> used for odometry.  These sensors are connected via voltage dividers 
>>>>>>>> to 
>>>>>>>> pins 33, 35, 36, 37, 38, 39, and 49 of P9, and are powered from the 
>>>>>>>> same 
>>>>>>>> power supply used to power the BeagleBone Black.  The System Manual 
>>>>>>>> has a 
>>>>>>>> rather explicit warning:
>>>>>>>>
>>>>>>>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT 
>>>>>>>> SUPPLIED TO THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE 
>>>>>>>> WARRANTY.
>>>>>>>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.
>>>>>>>>
>>>>>>>> My concern is the current arrangement would allow the sensors to 
>>>>>>>> begin driving the pins before the SYS_RESET line goes high; however, I 
>>>>>>>> am a 
>>>>>>>> software guy just starting down the hardware path.  Thus far many in 
>>>>>>>> the 
>>>>>>>> class have been using the robot without issue.  Is my concern invalid?
>>>>>>>>
>>>>>>>> Thank you for your time.
>>>>>>>>
>>>>>>>> -- 
>>>>>>>> For more options, visit http://beagleboard.org/discuss
>>>>>>>> --- 
>>>>>>>> You received this message because you are subscribed to the Google 
>>>>>>>> Groups "BeagleBoard" group.
>>>>>>>> To unsubscribe from this group and stop receiving emails from it, 
>>>>>>>> send an email to beagleboard...@googlegroups.com .
>>>>>>>>
>>>&g

Re: [beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

:) Attempts at humor on only one cup of coffee might not be so funny!


On Thu, Mar 6, 2014 at 9:14 AM, Gerald Coley  wrote:

> I am not sure how to take that!Not sure if it is luck or something else.
>
> Gerald
>
>
>
> On Thu, Mar 6, 2014 at 9:12 AM, Eric Palmer  wrote:
>
>> Awesome
>>
>> Gerald we are lucky to have you on this mail list and be participating so
>> much.
>>
>> Thanks
>>
>>
>> On Thu, Mar 6, 2014 at 10:09 AM, Gerald Coley wrote:
>>
>>> Yes you can do that  Use the 3.3V to enable the regulators.
>>>
>>> Gerald
>>>
>>>
>>>
>>> On Thu, Mar 6, 2014 at 9:03 AM, Matthew Witherwax wrote:
>>>
>>>> Thanks Gerald.  That is exactly the response I was expecting and
>>>> exactly the feeling I had.  Never really like playing Russian roulette
>>>> myself.  Do you see any issue with powering the sensors via a voltage
>>>> regulator like http://www.pololu.com/product/2098 that can be turned
>>>> on via a pin on the BBB once it is up and running?
>>>>
>>>>
>>>> On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley wrote:
>>>>
>>>>> I put that in there for a reason. It may not happen all the time, but
>>>>> eventually you could blow up the processor.
>>>>>
>>>>> Gerald
>>>>>
>>>>>
>>>>> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax 
>>>>> wrote:
>>>>>
>>>>>>  As part of the Control of Mobile Robotics class offered through
>>>>>> Cousera, the students are building robots based around the BeagleBone
>>>>>> Black.  The robot has 5 infrared distance sensors and 2 reflectance 
>>>>>> sensors
>>>>>> used for odometry.  These sensors are connected via voltage dividers to
>>>>>> pins 33, 35, 36, 37, 38, 39, and 49 of P9, and are powered from the same
>>>>>> power supply used to power the BeagleBone Black.  The System Manual has a
>>>>>> rather explicit warning:
>>>>>>
>>>>>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED
>>>>>> TO THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
>>>>>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.
>>>>>>
>>>>>> My concern is the current arrangement would allow the sensors to
>>>>>> begin driving the pins before the SYS_RESET line goes high; however, I 
>>>>>> am a
>>>>>> software guy just starting down the hardware path.  Thus far many in the
>>>>>> class have been using the robot without issue.  Is my concern invalid?
>>>>>>
>>>>>> Thank you for your time.
>>>>>>
>>>>>> --
>>>>>> For more options, visit http://beagleboard.org/discuss
>>>>>> ---
>>>>>> You received this message because you are subscribed to the Google
>>>>>> Groups "BeagleBoard" group.
>>>>>> To unsubscribe from this group and stop receiving emails from it,
>>>>>> send an email to beagleboard+unsubscr...@googlegroups.com.
>>>>>>
>>>>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>>>>
>>>>>
>>>>>  --
>>>>> For more options, visit http://beagleboard.org/discuss
>>>>> ---
>>>>> You received this message because you are subscribed to a topic in the
>>>>> Google Groups "BeagleBoard" group.
>>>>> To unsubscribe from this topic, visit
>>>>> https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe.
>>>>> To unsubscribe from this group and all its topics, send an email to
>>>>> beagleboard+unsubscr...@googlegroups.com.
>>>>>
>>>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>>>
>>>>
>>>>  --
>>>> For more options, visit http://beagleboard.org/discuss
>>>> ---
>>>> You received this message because you are subscribed to the Google
>>>> Groups "BeagleBoard" group.
>>>> To unsubscribe from this group and stop receiving emails from it, send
>>>> an email to beagleboard+unsubscr...@googlegroups.com.
>>>> For more options, visit https://groups.googl

Re: [beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

Thanks for all you do Gerald.


On Thu, Mar 6, 2014 at 9:09 AM, Gerald Coley  wrote:

> Yes you can do that  Use the 3.3V to enable the regulators.
>
> Gerald
>
>
>
> On Thu, Mar 6, 2014 at 9:03 AM, Matthew Witherwax wrote:
>
>> Thanks Gerald.  That is exactly the response I was expecting and exactly
>> the feeling I had.  Never really like playing Russian roulette myself.  Do
>> you see any issue with powering the sensors via a voltage regulator like
>> http://www.pololu.com/product/2098 that can be turned on via a pin on
>> the BBB once it is up and running?
>>
>>
>> On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley wrote:
>>
>>> I put that in there for a reason. It may not happen all the time, but
>>> eventually you could blow up the processor.
>>>
>>> Gerald
>>>
>>>
>>> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax wrote:
>>>
>>>>  As part of the Control of Mobile Robotics class offered through
>>>> Cousera, the students are building robots based around the BeagleBone
>>>> Black.  The robot has 5 infrared distance sensors and 2 reflectance sensors
>>>> used for odometry.  These sensors are connected via voltage dividers to
>>>> pins 33, 35, 36, 37, 38, 39, and 49 of P9, and are powered from the same
>>>> power supply used to power the BeagleBone Black.  The System Manual has a
>>>> rather explicit warning:
>>>>
>>>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO
>>>> THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
>>>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.
>>>>
>>>> My concern is the current arrangement would allow the sensors to begin
>>>> driving the pins before the SYS_RESET line goes high; however, I am a
>>>> software guy just starting down the hardware path.  Thus far many in the
>>>> class have been using the robot without issue.  Is my concern invalid?
>>>>
>>>> Thank you for your time.
>>>>
>>>> --
>>>> For more options, visit http://beagleboard.org/discuss
>>>> ---
>>>> You received this message because you are subscribed to the Google
>>>> Groups "BeagleBoard" group.
>>>> To unsubscribe from this group and stop receiving emails from it, send
>>>> an email to beagleboard+unsubscr...@googlegroups.com.
>>>>
>>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>>
>>>
>>>  --
>>> For more options, visit http://beagleboard.org/discuss
>>> ---
>>> You received this message because you are subscribed to a topic in the
>>> Google Groups "BeagleBoard" group.
>>> To unsubscribe from this topic, visit
>>> https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe.
>>> To unsubscribe from this group and all its topics, send an email to
>>> beagleboard+unsubscr...@googlegroups.com.
>>>
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>
>>  --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "BeagleBoard" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to beagleboard+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>
>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

The way I read the manual and understand Gerald is that it isn't safe any
more than it is safe to play Russian roulette because you don't always get
shot.  As Gerald said, you just might get lucky and not blow anything...
until you do.


On Thu, Mar 6, 2014 at 9:03 AM, Eric Palmer  wrote:

> If everything is driven form the same power source, even with voltage
> dividers or regulators, can we assume that turning on all devices at the
> same time, with one power switch, is safe or do we need to somehow put a
> delay into powering on everything but the BBB board?
>
> Eric
>
>
> On Thu, Mar 6, 2014 at 9:58 AM, Gerald Coley wrote:
>
>> I put that in there for a reason. It may not happen all the time, but
>> eventually you could blow up the processor.
>>
>> Gerald
>>
>>
>> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax wrote:
>>
>>> As part of the Control of Mobile Robotics class offered through Cousera,
>>> the students are building robots based around the BeagleBone Black.  The
>>> robot has 5 infrared distance sensors and 2 reflectance sensors used for
>>> odometry.  These sensors are connected via voltage dividers to pins 33, 35,
>>> 36, 37, 38, 39, and 49 of P9, and are powered from the same power supply
>>> used to power the BeagleBone Black.  The System Manual has a rather
>>> explicit warning:
>>>
>>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO
>>> THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
>>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.
>>>
>>> My concern is the current arrangement would allow the sensors to begin
>>> driving the pins before the SYS_RESET line goes high; however, I am a
>>> software guy just starting down the hardware path.  Thus far many in the
>>> class have been using the robot without issue.  Is my concern invalid?
>>>
>>> Thank you for your time.
>>>
>>> --
>>> For more options, visit http://beagleboard.org/discuss
>>> ---
>>> You received this message because you are subscribed to the Google
>>> Groups "BeagleBoard" group.
>>> To unsubscribe from this group and stop receiving emails from it, send
>>> an email to beagleboard+unsubscr...@googlegroups.com.
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>
>>  --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "BeagleBoard" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to beagleboard+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>
>
>
> --
> Eric Palmer
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

Thanks Gerald.  That is exactly the response I was expecting and exactly
the feeling I had.  Never really like playing Russian roulette myself.  Do
you see any issue with powering the sensors via a voltage regulator like
http://www.pololu.com/product/2098 that can be turned on via a pin on the
BBB once it is up and running?


On Thu, Mar 6, 2014 at 8:58 AM, Gerald Coley  wrote:

> I put that in there for a reason. It may not happen all the time, but
> eventually you could blow up the processor.
>
> Gerald
>
>
> On Thu, Mar 6, 2014 at 8:56 AM, Matthew Witherwax wrote:
>
>> As part of the Control of Mobile Robotics class offered through Cousera,
>> the students are building robots based around the BeagleBone Black.  The
>> robot has 5 infrared distance sensors and 2 reflectance sensors used for
>> odometry.  These sensors are connected via voltage dividers to pins 33, 35,
>> 36, 37, 38, 39, and 49 of P9, and are powered from the same power supply
>> used to power the BeagleBone Black.  The System Manual has a rather
>> explicit warning:
>>
>> NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO
>> THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
>> NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.
>>
>> My concern is the current arrangement would allow the sensors to begin
>> driving the pins before the SYS_RESET line goes high; however, I am a
>> software guy just starting down the hardware path.  Thus far many in the
>> class have been using the robot without issue.  Is my concern invalid?
>>
>> Thank you for your time.
>>
>> --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "BeagleBoard" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to beagleboard+unsubscr...@googlegroups.com.
>>
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>
>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/_5Puwswy-RQ/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[beagleboard] When to power sensors connected to the BeagleBone Black?

[Matthew Witherwax]

As part of the Control of Mobile Robotics class offered through Cousera, 
the students are building robots based around the BeagleBone Black.  The 
robot has 5 infrared distance sensors and 2 reflectance sensors used for 
odometry.  These sensors are connected via voltage dividers to pins 33, 35, 
36, 37, 38, 39, and 49 of P9, and are powered from the same power supply 
used to power the BeagleBone Black.  The System Manual has a rather 
explicit warning:

NOTE: DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO THE 
BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH.

My concern is the current arrangement would allow the sensors to begin 
driving the pins before the SYS_RESET line goes high; however, I am a 
software guy just starting down the hardware path.  Thus far many in the 
class have been using the robot without issue.  Is my concern invalid?

Thank you for your time.

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: OpenCV camera capture resolution error.

[Matthew Witherwax]

Moon,

OpenCV will report the invalid argument warning when something is not
supported, but should not prevent you from capturing video.  Are you
receiving any other errors?


On Wed, Feb 12, 2014 at 7:17 AM, Moon Walker  wrote:

> I have the same issue with C270.
> VIDIOC... invalid argument.
>
> I am able however captire images with fswebcam and capture video with
> ffmpeg.
> Only opencv CaptureFromCAM() throws this error.
>
> could someone give a hint?
>
> Thx
> Attila
>
>
> On Sunday, August 25, 2013 7:18:56 PM UTC+2, Dinesh Madusanke wrote:
>>
>> Dear all,
>>
>> I am running angstrom on a beaglebone Rev 6 and I used a Logitech C270
>> webcam with openCV for a vision application. Although I could capture
>> images with resolution 320 * 240 When I tried with 640 * 480 resolution I
>> get a select timeout error.
>> Here is my output.
>>
>> VIDIOC_QUERYMENU: Invalid argument
>> VIDIOC_QUERYMENU: Invalid argument
>> VIDIOC_QUERYMENU: Invalid argument
>> select timeout
>>
>> Please help me to resolve this problem.
>> Thanks.
>>
>>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/VUtMH7g5q38/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

If you bypass OpenCV and capture directly like we did, you should test to
see if you can capture successfully in YUYV format.  OpenCV can convert
YUYV to a Mat with less than 3% cpu use.  If you capture in MJPEG, you will
see cpu use of 90% or more to convert the image to a Mat.  This isn't so
bad on the Wandboard because it only consumes one core, but can be intense
on the single core BBB.  I can tell you from testing with the Wandboard
Quad, it can push 30 fps in YUYV over USB.  However, it is only possible to
stream from one camera at 30 fps in YUYV.  In short it is a tradeoff.  You
can either saturate the USB and save processing or save bandwidth and
increase processing. Something to consider depending on your needs.


On Thu, Jan 30, 2014 at 12:53 PM, Michael Darling wrote:

> Okay, so the problem you're having has to do with bugs in OpenCV, itself.
>  Unfortunately, the capture methods in OpenCV do not set the camera
> properties correctly for video4linux devices.  In other words, you may
> write the line of code to set the frame rate to 30 fps, but the camera
> isn't actually getting the instruction to change the frame rate.
>
> The fix Matthew and I have used is to just use our own video4linux capture
> code.  You might be able to modify the OpenCV source code, but the capture
> code is difficult to follow since there are so many layers of abstraction.
> (There are a lot of wrapper classes used to handle v4l2 devices, v4l1
> devices, Mac, Windows so that the programmer doesn't have to handle each
> camera differently depending on his/her system.)
>
> Hope that explains some things for you  :)
> - Mike
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

To piggy back on Mike's response, when we were testing the capture rate of
the BBB, we used a modified version of framegrabber that is attached to
this article
http://blog.lemoneerlabs.com/post/bbb-optimized-opencv-mjpeg-stream

It allows you to set all the parameters the regular framegrabber accepts
but converts each frame to an OpenCV Mat.  It is C code and as another word
of warning, I won't say the code is any less sloppy than Mike's :) It was
written for testing purposes.

The article itself details how to compile OpenCV to use NEON and
libjpeg-turbo courtesy of Mike.

I am surprised to hear the ODroid has trouble capturing higher than 15
fps.  I recently bought a Wanboard Quad, but the ODroid was on my short
list.

A few things to consider:

Have you tested with framegrabber to see if you can capture the raw frames
at a speed greater than 15 fps?  It could be that OpenCV is the bottle neck
and perhaps you should recompile it per Mike's instructions.

Is auto exposure turned off?  Even with the frame rate set to 30 fps, in
low light conditions, the camera increases exposure time to compensate
leading to about 15 fps.

Good luck, and as Mike said, if you need help, we will do out best.


On Wed, Jan 29, 2014 at 4:02 PM, Michael Darling wrote:

> All you have to do is adapt the frame grabber code for your needs.  I
> actually went ahead and rewrote the capture code to be object oriented so
> that I could conveniently use it with OpenCV's C++ interface.  You might
> find some of my code helpful as an example to work from.  It is in a public
> git repo:
> https://github.com/mdarling39/LinuxVision/blob/master/
>
> I think you would primarily be interested in taking a look at CamObj.hpp,
> CamObj.cpp, and v4l2Cap.h, v4l2Cap.cpp, and/or v4l2_c.h and v4l2_c.c.  As a
> word of warning, my code is sloppy and specific for my needs, but it does
> what I need it to do.  Feel free to borrow from it and modify it to your
> heart's content.
>
> I actually don't remember how all of this stuff works anymore, but you can
> look at main_threaded.cpp to see how I am using v4l2_c.h to get frames into
> a cv::Mat object.  If I remember right, I had to abandon the
> object-oriented approach for some reason so that later so that I could
> implement multi-threading using pthreads. I think the magic you are looking
> for is in the function v4l2_process_image(cv::Mat, const void), where the
> frame buffer is actually decoded and saved to a cv::Mat object. Once you
> have that, you're home free and can just deal with OpenCV.
>
> static void v4l2_process_image(cv::Mat &img, const void *p)
> {
> cv::Mat buff(img.cols, img.rows, CV_8UC3, (void*)p);
> img = cv::imdecode(buff,CV_LOAD_IMAGE_COLOR);
> }
>
>
> I hope that helps you to get started.  If you need any help, just ask.
>  I'll do my best to help where I can.
>
> Good luck,
> Mike
>
>
>
> On Wed, Jan 29, 2014 at 11:52 AM, Learning Opencv 
> wrote:
>
>> I am working with the C920 on an ODroid, similar to the BBB.  I am also
>> having a problem capturing more than 15fps in OpenCV, however, I need to
>> use OpenCV for doing processing on the video.  Since I am not just grabbing
>> frames, I can't do something like framegrabber.  Is there anyone who has
>> done this and have a solution.  I have tried changing settings on v4l
>> before running my code, but have had no luck.
>>
>> Thanks.
>>
>>
>> On Monday, November 4, 2013 7:07:58 AM UTC-5, Matthew Witherwax wrote:
>>
>>> Glad to hear our work is helping others.  Let us know how your endeavors
>>> go.
>>> -Matthew
>>>
>>>
>>> On Sun, Nov 3, 2013 at 3:22 PM,  wrote:
>>>
>>>> Excellent, excellent thread! I just purchased my BBB yesterday for a
>>>> personal project, and I've been reading for many many hours how and what
>>>> would be the best way to stream video from the BBB to a PC over WiFi with
>>>> the lowest latency as I could get. This thread, including all the links
>>>> that users posted here, were really helpful in understand the steps I
>>>> should take.
>>>>
>>>> I'm just running to the store in a few minutes to buy a C920 and start
>>>> trying stuff :) I'm glad I've waited and read a lot before buying the PS3
>>>> Eye... Thanks guys. I will update any results I achieve.
>>>>
>>>> --
>>>> For more options, visit http://beagleboard.org/discuss
>>>> ---
>>>> You received this message because you are subscribed to a topic in the
>>>> Google Groups "BeagleBoard" group.
>>>> To 

[beagleboard] Re: Read from LV-Maxsonar-EZ0 using uart2

[Matthew Witherwax]

Gustavo,

I posted a link to my blog below.  I experienced this problem a couple 
years ago when I first started with MaxBotix sonars.  The datasheet isn't 
100% clear, but the serial signal is inverted.  That is what the person in 
the RPi forum meant about the meaning of the 1s and 0s.  You cannot simply 
flip the received data because the whole stream is inverted (to include 
start bits, etc.).  You need to invert everything.  In my post you will 
find a simple circuit made of 2 resistors and a transistor that will invert 
the signal for you.  If you prefer, you can purchase a hex inverter to 
accomplish the same thing.

I hope it helps you.  To save you from finding my other posts, here is the 
link http://blog.lemoneerlabs.com/post/Hearing-aids

On Monday, November 4, 2013 11:57:41 AM UTC-6, Gustavo Oliveira wrote:
>
> Hello,
> I'm trying to read from a LV-Maxsonar-EZ0 using the serial interface.
>
> I have connected the wires correctly and I have placed an overlay in uart2.
> The problem is the data I'm reading from the sensor. I can only get 
> garbage, but its not completely wrong because the data changes according to 
> the distance to obstacle.
>
> The datasheet for the sensor can be found here: 
> datasheet
> .
>
> I searched google for a day and couldn't find anything...
> Someone posted in a raspberry pi forum that the problem is the meaning of 
> 1s and 0s, but I changed active_low to 1 and I got the same.
>
> I'm not very proficient with electronics, so I might take some time 
> following instructions.
> Nonetheless all the help will be welcome.
>
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Read from LV-Maxsonar-EZ0 using uart2

[Matthew Witherwax]

If you contact MaxBotix or check the specs on the Pololu page
http://www.pololu.com/product/723/ you can see it has the following outputs

   - Three interfaces (all are active simultaneously):
  - Serial output: asynchronous, logic-level, *inverted*, 9600 bps 8N1
  - Analog output: (Vcc/512) / inch (10 mV/inch when input voltage Vcc
  = 5 V)
  - Pulse width output: 147 μs/inch



On Tue, Nov 5, 2013 at 9:37 AM, Mike Bremford  wrote:

> At risk of asking the obvious, have you double checked you're putting out
> serial data? Your datasheet requires the BW pin to be floating or low to
> output out serial data, otherwise it puts out pulse data on the same pin.
>
> Before you try the inverter approach, maybe just put a multimeter on the
> Tx pin on the device - it should be high (ie 3.3V) most of the time. If
> it's transmitting once per second, NMEA0183-style, even then the voltage
> should be closer to 3.3V than GND. If it's closer to GND, then you'll need
> to invert it.
>
> I'm working with a whole stack of NMEA0183 devices and assuming they're
> properly functioning, the only thing you can really get wrong are baud
> rate, inverted signal, wrong pin (tx instead of rx, in which case you hear
> nothing) or software config error. For software, I just use screen -
> "screen /dev/ttyO2 9600" - rather than minicom or any of the other scripts.
> Much easier.
>
>
> On 5 November 2013 09:52, Gustavo Oliveira wrote:
>
>> I guess I did some mistake answering back there =P
>> It is in UART_RX.
>>
>> I search the internet and found that maybe I'm getting the inverted
>> messages, all the 1s as 0s and the 0s as 1s.
>>
>>
>> On 5 November 2013 09:50, Gustavo Oliveira wrote:
>>
>>> 1) I'm using the 3.3V pin, so the voltage is acceptable in p9_22.
>>>
>>> 2) What do you mean by setttings, the fields when I export the pin? Or
>>> the pin mode? I think mine are ok, what should they be?
>>>
>>> 3) I tried many applications, python scripts, c scripts, minicom...
>>>
>>>
>>> On 5 November 2013 05:26, Maxim Podbereznyy  wrote:
>>>
 1) I would place a voltage translator or a simple voltage divider based
 on two resistors to reduce 5 volts to the acceptable 3.3V.

 2) check the pinmux settings for that pin

 3) what terminal application do you use to read data? Check the serial
 port parameters and don't forget to disable the hardware flow control if 
 any
 05 нояб. 2013 г. 3:55 пользователь "Gustavo Oliveira" <
 gustavo.pinho...@gmail.com> написал:

> Hi, thank you for quick reply,
> I'm using a BeagleBone and Ubuntu 12.04.
>
> I have the TX connected to p9_22, which is uart2 RX.
>
> On Monday, November 4, 2013 7:38:06 PM UTC, lisarden wrote:
>>
>> hi!
>>
>> what board do you use and what OS?
>>
>> your datasheet says that VCC is +5V and the TX pin also work in 0-VCC
>> range. If you use beaglebone it accepts only 3.3V, however there can be
>> options
>>
>>
>> 2013/11/4 Gustavo Oliveira 
>>
>>> Hello,
>>> I'm trying to read from a LV-Maxsonar-EZ0 using the serial interface.
>>>
>>> I have connected the wires correctly and I have placed an overlay in
>>> uart2.
>>> The problem is the data I'm reading from the sensor. I can only get
>>> garbage, but its not completely wrong because the data changes 
>>> according to
>>> the distance to obstacle.
>>>
>>> The datasheet for the sensor can be found here: 
>>> datasheet
>>> .
>>>
>>> I searched google for a day and couldn't find anything...
>>> Someone posted in a raspberry pi forum that the problem is the
>>> meaning of 1s and 0s, but I changed active_low to 1 and I got the same.
>>>
>>> I'm not very proficient with electronics, so I might take some time
>>> following instructions.
>>> Nonetheless all the help will be welcome.
>>>
>>>  --
>>> For more options, visit http://beagleboard.org/discuss
>>> ---
>>> You received this message because you are subscribed to the Google
>>> Groups "BeagleBoard" group.
>>> To unsubscribe from this group and stop receiving emails from it,
>>> send an email to beagleboard...@googlegroups.com.
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>
>>
>>
>> --
>> LinkedIn - http://www.linkedin.com/in/maximpodbereznyy
>> Company - http://www.linkedin.com/company/mentorel
>> Facebook - https://www.facebook.com/mentorel.company
>>
>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to the Google
> Groups "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to beagleboard+unsubscr...@googlegroups.com.
>
> For more options, visit https://gro

Re: [beagleboard] Read from LV-Maxsonar-EZ0 using uart2

[Matthew Witherwax]

As an addendum, the circuit in my post would work at 3.3 V as well.

On Tuesday, November 5, 2013 9:12:14 AM UTC-6, Matthew Witherwax wrote:
>
> I believe my blog post http://blog.lemoneerlabs.com/post/Hearing-aidswill 
> solve your issue.  You need to build an actual inverter (or buy an IC 
> to do it for you).
>
> On Tuesday, November 5, 2013 3:52:54 AM UTC-6, Gustavo Oliveira wrote:
>>
>> I guess I did some mistake answering back there =P
>> It is in UART_RX.
>>
>> I search the internet and found that maybe I'm getting the inverted 
>> messages, all the 1s as 0s and the 0s as 1s.
>>
>>
>> On 5 November 2013 09:50, Gustavo Oliveira  wrote:
>>
>>> 1) I'm using the 3.3V pin, so the voltage is acceptable in p9_22.
>>>
>>> 2) What do you mean by setttings, the fields when I export the pin? Or 
>>> the pin mode? I think mine are ok, what should they be?
>>>
>>> 3) I tried many applications, python scripts, c scripts, minicom...
>>>
>>>
>>> On 5 November 2013 05:26, Maxim Podbereznyy  wrote:
>>>
>>>> 1) I would place a voltage translator or a simple voltage divider based 
>>>> on two resistors to reduce 5 volts to the acceptable 3.3V.
>>>>
>>>> 2) check the pinmux settings for that pin
>>>>
>>>> 3) what terminal application do you use to read data? Check the serial 
>>>> port parameters and don't forget to disable the hardware flow control if 
>>>> any
>>>> 05 нояб. 2013 г. 3:55 пользователь "Gustavo Oliveira" <
>>>> gustavo@gmail.com> написал:
>>>>
>>>>> Hi, thank you for quick reply,
>>>>> I'm using a BeagleBone and Ubuntu 12.04.
>>>>>
>>>>> I have the TX connected to p9_22, which is uart2 RX.
>>>>>
>>>>> On Monday, November 4, 2013 7:38:06 PM UTC, lisarden wrote:
>>>>>>
>>>>>> hi!
>>>>>>
>>>>>> what board do you use and what OS?
>>>>>>
>>>>>> your datasheet says that VCC is +5V and the TX pin also work in 0-VCC 
>>>>>> range. If you use beaglebone it accepts only 3.3V, however there can be 
>>>>>> options
>>>>>>
>>>>>>
>>>>>> 2013/11/4 Gustavo Oliveira 
>>>>>>
>>>>>>> Hello,
>>>>>>> I'm trying to read from a LV-Maxsonar-EZ0 using the serial interface.
>>>>>>>
>>>>>>> I have connected the wires correctly and I have placed an overlay in 
>>>>>>> uart2.
>>>>>>> The problem is the data I'm reading from the sensor. I can only get 
>>>>>>> garbage, but its not completely wrong because the data changes 
>>>>>>> according to 
>>>>>>> the distance to obstacle.
>>>>>>>
>>>>>>> The datasheet for the sensor can be found here: 
>>>>>>> datasheet<http://www.maxbotix.com/documents/MB1000_Datasheet.pdf>
>>>>>>> .
>>>>>>>
>>>>>>> I searched google for a day and couldn't find anything...
>>>>>>> Someone posted in a raspberry pi forum that the problem is the 
>>>>>>> meaning of 1s and 0s, but I changed active_low to 1 and I got the same.
>>>>>>>
>>>>>>> I'm not very proficient with electronics, so I might take some time 
>>>>>>> following instructions.
>>>>>>> Nonetheless all the help will be welcome.
>>>>>>>
>>>>>>>  -- 
>>>>>>> For more options, visit http://beagleboard.org/discuss
>>>>>>> --- 
>>>>>>> You received this message because you are subscribed to the Google 
>>>>>>> Groups "BeagleBoard" group.
>>>>>>> To unsubscribe from this group and stop receiving emails from it, 
>>>>>>> send an email to beagleboard...@**googlegroups.com.
>>>>>>> For more options, visit 
>>>>>>> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out>
>>>>>>> .
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> -- 
>>>>>> LinkedIn - 
>>>>>> http://www.linked

Re: [beagleboard] Read from LV-Maxsonar-EZ0 using uart2

[Matthew Witherwax]

I believe my blog post http://blog.lemoneerlabs.com/post/Hearing-aids will 
solve your issue.  You need to build an actual inverter (or buy an IC to do 
it for you).

On Tuesday, November 5, 2013 3:52:54 AM UTC-6, Gustavo Oliveira wrote:
>
> I guess I did some mistake answering back there =P
> It is in UART_RX.
>
> I search the internet and found that maybe I'm getting the inverted 
> messages, all the 1s as 0s and the 0s as 1s.
>
>
> On 5 November 2013 09:50, Gustavo Oliveira 
> > wrote:
>
>> 1) I'm using the 3.3V pin, so the voltage is acceptable in p9_22.
>>
>> 2) What do you mean by setttings, the fields when I export the pin? Or 
>> the pin mode? I think mine are ok, what should they be?
>>
>> 3) I tried many applications, python scripts, c scripts, minicom...
>>
>>
>> On 5 November 2013 05:26, Maxim Podbereznyy 
>> > wrote:
>>
>>> 1) I would place a voltage translator or a simple voltage divider based 
>>> on two resistors to reduce 5 volts to the acceptable 3.3V.
>>>
>>> 2) check the pinmux settings for that pin
>>>
>>> 3) what terminal application do you use to read data? Check the serial 
>>> port parameters and don't forget to disable the hardware flow control if any
>>> 05 нояб. 2013 г. 3:55 пользователь "Gustavo Oliveira" <
>>> gustavo@gmail.com > написал:
>>>
 Hi, thank you for quick reply,
 I'm using a BeagleBone and Ubuntu 12.04.

 I have the TX connected to p9_22, which is uart2 RX.

 On Monday, November 4, 2013 7:38:06 PM UTC, lisarden wrote:
>
> hi!
>
> what board do you use and what OS?
>
> your datasheet says that VCC is +5V and the TX pin also work in 0-VCC 
> range. If you use beaglebone it accepts only 3.3V, however there can be 
> options
>
>
> 2013/11/4 Gustavo Oliveira 
>
>> Hello,
>> I'm trying to read from a LV-Maxsonar-EZ0 using the serial interface.
>>
>> I have connected the wires correctly and I have placed an overlay in 
>> uart2.
>> The problem is the data I'm reading from the sensor. I can only get 
>> garbage, but its not completely wrong because the data changes according 
>> to 
>> the distance to obstacle.
>>
>> The datasheet for the sensor can be found here: 
>> datasheet
>> .
>>
>> I searched google for a day and couldn't find anything...
>> Someone posted in a raspberry pi forum that the problem is the 
>> meaning of 1s and 0s, but I changed active_low to 1 and I got the same.
>>
>> I'm not very proficient with electronics, so I might take some time 
>> following instructions.
>> Nonetheless all the help will be welcome.
>>
>>  -- 
>> For more options, visit http://beagleboard.org/discuss
>> --- 
>> You received this message because you are subscribed to the Google 
>> Groups "BeagleBoard" group.
>> To unsubscribe from this group and stop receiving emails from it, 
>> send an email to beagleboard...@**googlegroups.com.
>> For more options, visit 
>> https://groups.google.com/**groups/opt_out
>> .
>>
>
>
>
> -- 
> LinkedIn - 
> http://www.linkedin.com/in/**maximpodbereznyy
> Company - 
> http://www.linkedin.com/**company/mentorel
> Facebook - 
> https://www.facebook.com/**mentorel.company
>  
  -- 
 For more options, visit http://beagleboard.org/discuss
 --- 
 You received this message because you are subscribed to the Google 
 Groups "BeagleBoard" group.
 To unsubscribe from this group and stop receiving emails from it, send 
 an email to beagleboard...@googlegroups.com .
 For more options, visit https://groups.google.com/groups/opt_out.

>>>  -- 
>>> For more options, visit http://beagleboard.org/discuss
>>> --- 
>>> You received this message because you are subscribed to a topic in the 
>>> Google Groups "BeagleBoard" group.
>>> To unsubscribe from this topic, visit 
>>> https://groups.google.com/d/topic/beagleboard/gOK8R4_mRzw/unsubscribe.
>>> To unsubscribe from this group and all its topics, send an email to 
>>> beagleboard...@googlegroups.com .
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>
>>
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Glad to hear our work is helping others.  Let us know how your endeavors go.
-Matthew


On Sun, Nov 3, 2013 at 3:22 PM,  wrote:

> Excellent, excellent thread! I just purchased my BBB yesterday for a
> personal project, and I've been reading for many many hours how and what
> would be the best way to stream video from the BBB to a PC over WiFi with
> the lowest latency as I could get. This thread, including all the links
> that users posted here, were really helpful in understand the steps I
> should take.
>
> I'm just running to the store in a few minutes to buy a C920 and start
> trying stuff :) I'm glad I've waited and read a lot before buying the PS3
> Eye... Thanks guys. I will update any results I achieve.
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] OpenCV Development Tool install

[Matthew Witherwax]

This blog post might help you 
http://blog.lemoneerlabs.com/post/bbb-optimized-opencv-mjpeg-stream

On Saturday, October 19, 2013 8:58:57 PM UTC-5, Walter Schilling wrote:
>
>  Is it not possible then to cross compile openCV programs under Ubuntu on 
> a desktop and transfer the images to the Beaglebone?  Compiling right on 
> the embedded target isn't the greatest way to do things for embedded 
> systems development.
>  --
> *From:* beagl...@googlegroups.com  
> [beagl...@googlegroups.com] 
> on behalf of Bence Magyar [mw.m...@gmail.com ]
> *Sent:* Friday, October 18, 2013 8:54 AM
> *To:* beagl...@googlegroups.com 
> *Subject:* Re: [beagleboard] OpenCV Development Tool install
>
>   A previous post on this list: 
> https://groups.google.com/forum/#!topic/beagleboard/Smysj-UjYfE
>
>  For me installing ubuntu and compiling my stuff on the beaglebone just 
> worked.
>  
>
> 2013/10/18 Walter Schilling >
>
>> Hello. 
>>
>>  I'm having what very much is a beginners question, but thusfar I 
>> haven't seen a definitive answer.  I am starting work with the BeagleBone 
>> Black running Angstrom and I would like to cross compile an OpenCV program. 
>>  My development host is running XUbuntu, and I've installed the gnueabi 
>> cross compiler.  However, I'm having trouble figuring out how to go about 
>> installing the libraries for OpenCV.  I know I need them to be cross 
>> compiled for the Angstrom target, but is this available pre-packaged or do 
>> I need to build the OpenCV libraries from scratch using a cross compiler?
>>
>>  Thanks for the answer to the (seemingly) basic question.
>>
>>  Walt
>>  
>>   -- 
>> For more options, visit http://beagleboard.org/discuss
>> --- 
>> You received this message because you are subscribed to the Google Groups 
>> "BeagleBoard" group.
>> To unsubscribe from this group and stop receiving emails from it, send an 
>> email to beagleboard...@googlegroups.com .
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>  
>  -- 
> For more options, visit http://beagleboard.org/discuss
> --- 
> You received this message because you are subscribed to a topic in the 
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit 
> https://groups.google.com/d/topic/beagleboard/cSLzp_dmVMw/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to 
> beagleboard...@googlegroups.com .
> For more options, visit https://groups.google.com/groups/opt_out.
>   

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[beagleboard] Re: Sending data through wifi

[Matthew Witherwax]

It is absolutely possible.  You just need to figure out how to format your 
data to send over wifi.  I send MJPG frames as a stream over wifi on my 
blog here http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming   You could 
take a similar approach to send anything you wanted.  In my example, you 
can think of the frames as sensor data I am sending out over wifi to one or 
more computers.  I used 0MQ to manage the low level network/sockets, but 
you are free to work at that level as well.

On Tuesday, October 15, 2013 4:01:46 AM UTC-5, danji...@gmail.com wrote:
>
> Hello, I would like if it's possible to send and receive data obtained, 
> for example, from some sensors placed on the beaglebone black to another 
> computer or other device, I searched but sadly did not find a lot of 
> solutions, I would like to know if this is doable using a wifi dongle, 
> since it's much cheaper than buying other devices such as an X-Bee.
>
> Thanks in advance for your help.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: Wifi on BBB 3.8.x - Are there drivers for any USB wifi adapters?

[Matthew Witherwax]

I am using the TP-LINK TL-WN722N without any issues.  I have it on an
*unpowered
*hub with a Logitech C920.  I am able to stream the webcam feed over wifi
without problems.  I have documented setting up WIFI under Arch Linux at
http://blog.lemoneerlabs.com/post/The-fruits-of-my-labor  At that time, I
was using an adapter based on the RTl8192cu chipset.  That adapter
eventually stopped working, and I replaced it with the TP-LINK adapter.  It
was a simple case of plug and play; no further configuration was needed
after having performed the steps on my blog (driver is included in Arch and
most likely in your distro as well).  In this case, it was worthwhile to
spend a bit more on a better WIFI adapter.

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

RE: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Jim,

Glad to hear your webcam is working. Did you have any issues with the MJPG 
frames not being full jpegs?  Some people have reported to me that their 
webcams do not generate complete jpegs.  I have a fix for it, and it would be 
nice to have a list of webcams that require it.

Matthew Witherwax

-Original Message-
From: "shedmeister" 
Sent: 10/3/2013 10:41 PM
To: "beagleboard@googlegroups.com" 
Subject: [beagleboard] Re: problems with webcams

Hi Mike,


Yes, I am doing additional OpenCV processing, and have 4 video windows 
displayed, 2 being updated in "real-time" (hah!).  I have capture running in a 
separate thread.  My frame processing rate is well under 1 fps, so I'm ecstatic 
with 24 fps capture rate.


Thanks again!
 Jim


-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to a topic in the Google 
Groups "BeagleBoard" group.
To unsubscribe from this topic, visit 
https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
To unsubscribe from this group and all its topics, send an email to 
beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Streaming Video (from Webcam to Wifi)

[Matthew Witherwax]

I have been working on this recently and have posted some articles on my 
blog that might help you.  In particular you might be interested in 
http://blog.lemoneerlabs.com/post/BBB-webcams and 
http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming

Hope these help.  I will have more to post soon based on some work with 
another BBB user on increasing frame rates.

Matthew

On Sunday, September 29, 2013 11:42:38 AM UTC-5, Heron Yang wrote:
>
> ok!
> thanks for helping me so far :)
>
> On Sunday, September 29, 2013 9:51:01 AM UTC+8, Gerald wrote:
>>
>> I suggest you search the forum. A lot of work has been done on 
>> BeagleBoneBlack using USB cameras that have built in compression and they 
>> work pretty well. See what others have done and what they are getting and 
>> see if that meets what you are looking for.
>>
>> Gerald'
>>
>>
>> On Sat, Sep 28, 2013 at 8:19 PM, Heron Yang  wrote:
>>
>>> I have one BeagleBoard C4, which is borrowed from my senior.Therefore, I 
>>> am considering getting a new one. I would also like to know which 
>>> BeagleBoard will meet my needs.
>>>
>>> Best,
>>> Heron
>>>
>>>
>>> On Sunday, September 29, 2013 4:44:04 AM UTC+8, Gerald wrote:
>>>
 Which BeagleBoard do you have?

 Gerald



 On Sat, Sep 28, 2013 at 11:02 AM, Heron Yang wrote:

> Hi guys!!
>
> I am a newbie to beagleboard, all I've done is installing different 
> OS, then typed few simple commands on it. I am not a native English 
> speaker, sorry if there's bad English in this mail.
>
> I've disassembled one of the remote control cars I played with when I 
> was little, and controlled the car using Arduino. However, so far, I 
> still 
> need a USB cable to connect to Arduino (it's not a remote control car at 
> all). Now, I would like to switch to beagleboard and install a webcam on 
> it. Then, I can control the car and see the live video from the webcam 
> via 
> local internet (wireless).
>
> However, I don't really know how to get started with this topic, can 
> anyone give me some suggestions? Thanks a lot :)
>
> Best,
> Heron
>
> -- 
> For more options, visit http://beagleboard.org/discuss
> --- 
> You received this message because you are subscribed to the Google 
> Groups "BeagleBoard" group.
> To unsubscribe from this group and stop receiving emails from it, send 
> an email to beagleboard...@**googlegroups.com.
>
> For more options, visit 
> https://groups.google.com/**groups/opt_out
> .
>

  -- 
>>> For more options, visit http://beagleboard.org/discuss
>>> --- 
>>> You received this message because you are subscribed to the Google 
>>> Groups "BeagleBoard" group.
>>> To unsubscribe from this group and stop receiving emails from it, send 
>>> an email to beagleboard...@googlegroups.com.
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>
>>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

-o is not used to indicate which frames to convert to OpenCV Mats and 
requires an integer argument
should read
-o is now used to indicate which frames to convert to OpenCV Mats and 
requires an integer argument

On Thursday, September 26, 2013 6:46:39 AM UTC-5, Matthew Witherwax wrote:
>
> Mike,
>
> Here is the cleaned up one.  Here are the differences:
> -o is not used to indicate which frames to convert to OpenCV Mats and 
> requires an integer argument
> -o 1 would convert every frame
> -o 2 would convert every 2nd or ever other, etc
> default is 1
>
> -p is similar to -o in the original framegrabber.  However, it doesn't 
> actually output anything.  It just controls if any frames are to be 
> converted.
>
> Captured count and processed count variables have been renamed and moved 
> to the top.
>
> Formatting has been corrected.
>
>
> Testing of your procedure to follow.
>
>
> On Wed, Sep 25, 2013 at 12:55 PM, Matthew Witherwax wrote:
>
>> Mike,
>>
>> Looking over the code in you document, I noticed some formatting was off 
>> and I needed to clean up the way I handled processing the subset of the 
>> frames.  I am cleaning things up and will get you a new version shortly.
>>
>>
>> On Tue, Sep 24, 2013 at 8:53 PM, Michael Darling wrote:
>>
>>> Thanks!  You're absolutely welcome to distribute it freely. I don't have 
>>> my own website so that's a great way to share the information.
>>>
>>> Luckily I have most of my CV algorithm done. I have a bit of cleaning up 
>>> to do but most of my work is implementing hardware from here on out.
>>>
>>> Thanks again SO much for your help!  I look forward to getting feedback 
>>> on the write up.
>>>
>>> -Mike
>>>
>>>
>>> On Tuesday, September 24, 2013, Matthew Witherwax wrote:
>>>
>>>> Mike,
>>>>
>>>> Great write up.  When I have some free time, I will replicate your 
>>>> steps on my BBB running Arch Linux.  Not sure if you have a personal 
>>>> website, but would you mind me posting this to my blog once it makes it 
>>>> out 
>>>> of draft?
>>>>
>>>> I look forward to seeing your aircraft in action; on to the CV problems!
>>>>
>>>>
>>>> On Tue, Sep 24, 2013 at 7:39 PM, Michael Darling wrote:
>>>>
>>>> Hi Richard,
>>>>
>>>> Here is a summary of what I ended up doing to get 30 fps out of the 
>>>> BBB. You are right -- it simply came down to taking advantage of NEON 
>>>> hardware acceleration.  My little "How-To" guide might be a bit verbose, 
>>>>  but you can skip all of the background information and skip right to the 
>>>> steps I took if you like. However reading some of the background 
>>>> information might give you some more insight into what I have already 
>>>> tried 
>>>> with the PS3 Eye (along with many others like Matthew) and what we have 
>>>> learned. Its also chock-full of great references on the topic.
>>>>
>>>> Right now, I am considering this a DRAFT as I have not gone back 
>>>> through to make sure that all the commands I pasted will work verbatim. If 
>>>> you're pretty comfortable in Linux, I'm sure this is enough for you to 
>>>> replicate what I have done.
>>>>
>>>> I wrote it up in LaTeX, as that was the easiest for me, so here it is 
>>>> in both PDF and HTML format.
>>>>
>>>> Best of luck.  If you end up taking a look at this, please let me know 
>>>> if you have any comments or suggestions for improvement.
>>>>
>>>> -Mike
>>>>
>>>>
>>>> On Tue, Sep 24, 2013 at 3:52 PM, rh_ wrote:
>>>>
>>>> On Tue, 24 Sep 2013 13:41:14 -0500
>>>> Matthew Witherwax 
>>>> wrote:
>>>>
>>>> > Richard,
>>>> >
>>>> > Please see the post
>>>> > http://blog.lemoneerlabs.com/post/BBB-webcamsconcerning the PS3Eye,
>>>> > C920, and frame rates.  I believe it will answer
>>>> > your questions.
>>>>
>>>> Ok it seems that OpenCV is the limiter. But the camera is significant.
>>>> I like the idea of using a USB camera due to low cost. But I dont like
>>>> it due to limited features.  However the limitations of cheap USB might
>>>> be overcome by using two cameras. Although only to a

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Mike,

Here is the cleaned up one.  Here are the differences:
-o is not used to indicate which frames to convert to OpenCV Mats and
requires an integer argument
-o 1 would convert every frame
-o 2 would convert every 2nd or ever other, etc
default is 1

-p is similar to -o in the original framegrabber.  However, it doesn't
actually output anything.  It just controls if any frames are to be
converted.

Captured count and processed count variables have been renamed and moved to
the top.

Formatting has been corrected.


Testing of your procedure to follow.


On Wed, Sep 25, 2013 at 12:55 PM, Matthew Witherwax wrote:

> Mike,
>
> Looking over the code in you document, I noticed some formatting was off
> and I needed to clean up the way I handled processing the subset of the
> frames.  I am cleaning things up and will get you a new version shortly.
>
>
> On Tue, Sep 24, 2013 at 8:53 PM, Michael Darling 
> wrote:
>
>> Thanks!  You're absolutely welcome to distribute it freely. I don't have
>> my own website so that's a great way to share the information.
>>
>> Luckily I have most of my CV algorithm done. I have a bit of cleaning up
>> to do but most of my work is implementing hardware from here on out.
>>
>> Thanks again SO much for your help!  I look forward to getting feedback
>> on the write up.
>>
>> -Mike
>>
>>
>> On Tuesday, September 24, 2013, Matthew Witherwax wrote:
>>
>>> Mike,
>>>
>>> Great write up.  When I have some free time, I will replicate your steps
>>> on my BBB running Arch Linux.  Not sure if you have a personal website, but
>>> would you mind me posting this to my blog once it makes it out of draft?
>>>
>>> I look forward to seeing your aircraft in action; on to the CV problems!
>>>
>>>
>>> On Tue, Sep 24, 2013 at 7:39 PM, Michael Darling >> > wrote:
>>>
>>> Hi Richard,
>>>
>>> Here is a summary of what I ended up doing to get 30 fps out of the BBB.
>>> You are right -- it simply came down to taking advantage of NEON hardware
>>> acceleration.  My little "How-To" guide might be a bit verbose,  but you
>>> can skip all of the background information and skip right to the steps I
>>> took if you like. However reading some of the background information might
>>> give you some more insight into what I have already tried with the PS3 Eye
>>> (along with many others like Matthew) and what we have learned. Its also
>>> chock-full of great references on the topic.
>>>
>>> Right now, I am considering this a DRAFT as I have not gone back through
>>> to make sure that all the commands I pasted will work verbatim. If you're
>>> pretty comfortable in Linux, I'm sure this is enough for you to replicate
>>> what I have done.
>>>
>>> I wrote it up in LaTeX, as that was the easiest for me, so here it is in
>>> both PDF and HTML format.
>>>
>>> Best of luck.  If you end up taking a look at this, please let me know
>>> if you have any comments or suggestions for improvement.
>>>
>>> -Mike
>>>
>>>
>>> On Tue, Sep 24, 2013 at 3:52 PM, rh_ wrote:
>>>
>>> On Tue, 24 Sep 2013 13:41:14 -0500
>>> Matthew Witherwax 
>>> wrote:
>>>
>>> > Richard,
>>> >
>>> > Please see the post
>>> > http://blog.lemoneerlabs.com/post/BBB-webcamsconcerning the PS3Eye,
>>> > C920, and frame rates.  I believe it will answer
>>> > your questions.
>>>
>>> Ok it seems that OpenCV is the limiter. But the camera is significant.
>>> I like the idea of using a USB camera due to low cost. But I dont like
>>> it due to limited features.  However the limitations of cheap USB might
>>> be overcome by using two cameras. Although only to a small degree.
>>> Probably need a camera cape to get at the camera features. And a
>>> feature-full camera.  I am thinking of repurposing a video camera
>>> as most have lots of features but are fairly cheap.
>>>
>>> --
>>> For more options, visit http://beagleboard.org/discuss
>>> ---
>>> You received this message because you are subscribed to a topic in the
>>> Google Groups "BeagleBoard" group.
>>> To unsubscribe from this topic, visit
>>> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
>>> To unsubscribe from this group and all its topics, send an email to
>>> beagleboard+unsubscr...@googlegroups.com.
>>

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Mike,

Looking over the code in you document, I noticed some formatting was off
and I needed to clean up the way I handled processing the subset of the
frames.  I am cleaning things up and will get you a new version shortly.


On Tue, Sep 24, 2013 at 8:53 PM, Michael Darling wrote:

> Thanks!  You're absolutely welcome to distribute it freely. I don't have
> my own website so that's a great way to share the information.
>
> Luckily I have most of my CV algorithm done. I have a bit of cleaning up
> to do but most of my work is implementing hardware from here on out.
>
> Thanks again SO much for your help!  I look forward to getting feedback on
> the write up.
>
> -Mike
>
>
> On Tuesday, September 24, 2013, Matthew Witherwax wrote:
>
>> Mike,
>>
>> Great write up.  When I have some free time, I will replicate your steps
>> on my BBB running Arch Linux.  Not sure if you have a personal website, but
>> would you mind me posting this to my blog once it makes it out of draft?
>>
>> I look forward to seeing your aircraft in action; on to the CV problems!
>>
>>
>> On Tue, Sep 24, 2013 at 7:39 PM, Michael Darling 
>> wrote:
>>
>> Hi Richard,
>>
>> Here is a summary of what I ended up doing to get 30 fps out of the BBB.
>> You are right -- it simply came down to taking advantage of NEON hardware
>> acceleration.  My little "How-To" guide might be a bit verbose,  but you
>> can skip all of the background information and skip right to the steps I
>> took if you like. However reading some of the background information might
>> give you some more insight into what I have already tried with the PS3 Eye
>> (along with many others like Matthew) and what we have learned. Its also
>> chock-full of great references on the topic.
>>
>> Right now, I am considering this a DRAFT as I have not gone back through
>> to make sure that all the commands I pasted will work verbatim. If you're
>> pretty comfortable in Linux, I'm sure this is enough for you to replicate
>> what I have done.
>>
>> I wrote it up in LaTeX, as that was the easiest for me, so here it is in
>> both PDF and HTML format.
>>
>> Best of luck.  If you end up taking a look at this, please let me know if
>> you have any comments or suggestions for improvement.
>>
>> -Mike
>>
>>
>> On Tue, Sep 24, 2013 at 3:52 PM, rh_  wrote:
>>
>> On Tue, 24 Sep 2013 13:41:14 -0500
>> Matthew Witherwax 
>> wrote:
>>
>> > Richard,
>> >
>> > Please see the post
>> > http://blog.lemoneerlabs.com/post/BBB-webcamsconcerning the PS3Eye,
>> > C920, and frame rates.  I believe it will answer
>> > your questions.
>>
>> Ok it seems that OpenCV is the limiter. But the camera is significant.
>> I like the idea of using a USB camera due to low cost. But I dont like
>> it due to limited features.  However the limitations of cheap USB might
>> be overcome by using two cameras. Although only to a small degree.
>> Probably need a camera cape to get at the camera features. And a
>> feature-full camera.  I am thinking of repurposing a video camera
>> as most have lots of features but are fairly cheap.
>>
>> --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to a topic in the
>> Google Groups "BeagleBoard" group.
>> To unsubscribe from this topic, visit
>> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to
>> beagleboard+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>  --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to a topic in the
>> Google Groups "BeagleBoard" group.
>> To unsubscribe from this topic, visit
>> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to
>> beagleboard+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>  --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to a topic in the
>> Google Groups "BeagleBoard" group.
>> To unsubscribe from this
>
>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> Yo

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Mike,

Great write up.  When I have some free time, I will replicate your steps on
my BBB running Arch Linux.  Not sure if you have a personal website, but
would you mind me posting this to my blog once it makes it out of draft?

I look forward to seeing your aircraft in action; on to the CV problems!


On Tue, Sep 24, 2013 at 7:39 PM, Michael Darling wrote:

> Hi Richard,
>
> Here is a summary of what I ended up doing to get 30 fps out of the BBB.
> You are right -- it simply came down to taking advantage of NEON hardware
> acceleration.  My little "How-To" guide might be a bit verbose,  but you
> can skip all of the background information and skip right to the steps I
> took if you like. However reading some of the background information might
> give you some more insight into what I have already tried with the PS3 Eye
> (along with many others like Matthew) and what we have learned. Its also
> chock-full of great references on the topic.
>
> Right now, I am considering this a DRAFT as I have not gone back through
> to make sure that all the commands I pasted will work verbatim. If you're
> pretty comfortable in Linux, I'm sure this is enough for you to replicate
> what I have done.
>
> I wrote it up in LaTeX, as that was the easiest for me, so here it is in
> both PDF and HTML format.
>
> Best of luck.  If you end up taking a look at this, please let me know if
> you have any comments or suggestions for improvement.
>
> -Mike
>
>
> On Tue, Sep 24, 2013 at 3:52 PM, rh_  wrote:
>
>> On Tue, 24 Sep 2013 13:41:14 -0500
>> Matthew Witherwax 
>> wrote:
>>
>> > Richard,
>> >
>> > Please see the post
>> > http://blog.lemoneerlabs.com/post/BBB-webcamsconcerning the PS3Eye,
>> > C920, and frame rates.  I believe it will answer
>> > your questions.
>>
>> Ok it seems that OpenCV is the limiter. But the camera is significant.
>> I like the idea of using a USB camera due to low cost. But I dont like
>> it due to limited features.  However the limitations of cheap USB might
>> be overcome by using two cameras. Although only to a small degree.
>> Probably need a camera cape to get at the camera features. And a
>> feature-full camera.  I am thinking of repurposing a video camera
>> as most have lots of features but are fairly cheap.
>>
>> --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to a topic in the
>> Google Groups "BeagleBoard" group.
>> To unsubscribe from this topic, visit
>> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to
>> beagleboard+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>
>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

[beagleboard] Re: problems with webcams

[Matthew Witherwax]

Richard,

Please see the post http://blog.lemoneerlabs.com/post/BBB-webcamsconcerning the 
PS3Eye, C920, and frame rates.  I believe it will answer 
your questions.
On Tuesday, September 24, 2013 12:50:05 PM UTC-5, rh_ wrote:
>
> On Mon, 23 Sep 2013 01:48:18 -0700 
> Michael Darling > 
> wrote: 
>
> > I have confirmed that it is indeed possible to grab AND convert 
> > frames at 640x480 and 30 fps with the BBB and Logitech C920 operating 
>
> The ps3 eye could not do this or have you tried yet? 
>
> > in MJPEG mode. My solution was to basically install libjpeg-turbo 
> > from source with NEON enabled and then building and installing OpenCV 
> > from source, using libjpeg-turbo as the JPEG codec. I also built 
> > OpenCV with NEON enabled. 
> > 
> > Here is sample output with every frame being processed. The 'top' 
> > utility shows about 50% CPU and only about 2% memory usage. Before 
> > executing the code, I set the CPU to operate at constant 1Ghz using 
> > "sudo cpufreq-set -g performance" so that there isn't a "slow start" 
> > while the BBB starts grabbing frames at 300 Mhz before it finally 
> > kicks into 1Ghz under load. 
> > 
> > time ./framegrabber -f mjpeg -H 480 -W 640 -c 1000 -I 30 -o 
> > Startup took 0.00 seconds 
> > Captured 1000 frames and Processed 1000 in 13.94 seconds 
> > Shutdown took 0.01 seconds 
> > 
> > 
> > real0m33.760s 
> > user0m11.566s 
> > sys0m2.518s 
> > 
> > I ended up using distcc to do a distributed cross-build of OpenCV on 
> > my PC, but still had problems with running out of space trying to 
> > store all of the source and object files on the 2GB eMMC on the BBB. 
> > I ended up having to mount an ext2 formatted filesystem using a USB 
> > thumb drive hooked up to the BBB and building OpenCV from there.  I 
> > probably ended up doing a lot of extraneous things that had little to 
> > no effect but I do have a working process for those who need to get 
> > 30 fps.  I need to go back and clean up some notes I took and then I 
> > plan to post a step-by-step guide for anybody else who wants to 
> > replicate what I did. 
>
> Will you say what the application is? Or at least is it a stationary 
> camera? Or is it something like for robot vision?  Using that Motion 
> app (mentioned previously) would get higher frame-rate, I think. 
> Unless Motion is post-processing. I'm sure not all USB cams are 
> created equal. But I wonder how much can be done via USB. 
> Seems to me that image substraction (or whatever the correct term) 
> would probably need to happen at the hardware level to get any 
> capture rate increase. So maybe there's no way to get a higher 
> frame rate due to hardware limitations. 
>
> > 
> > Thanks, 
> > -Mike 
> > 
> > 
> > On Sat, Sep 21, 2013 at 4:48 PM, Matthew Witherwax 
> > >wrote: 
> > 
> > > Jon, 
> > > 
> > > I hope you find it useful.  I would appreciate any feedback you 
> > > have to give. 
> > > 
> > > Best of luck, 
> > > Matthew 
> > > 
> > > 
> > > On Sat, Sep 21, 2013 at 4:54 AM,  > > +bqq9...@public.gmane.org > wrote: 
> > > 
> > >> Matthew, 
> > >> 
> > >> Thanks! That may be really useful for me. Am messing around with a 
> > >> PTZ camera at the moment, and lag in the video stream has been a 
> > >> bit of a problem so far.. 
> > >> 
> > >> Regards, 
> > >> Jon 
> > >> 
> > >> 
> > >> On Friday, 20 September 2013 14:01:23 UTC+1, Matthew Witherwax 
> > >> wrote: 
> > >>> 
> > >>> William, 
> > >>> 
> > >>> I have posted my streaming code and writeup here 
> > >>> http://blog.lemoneerlabs.com/**post/bbb-mjpeg-streaming<
> http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming> 
> > >>> 
> > >>> 
> > >>>  -- 
> > >> For more options, visit http://beagleboard.org/discuss 
> > >> --- 
> > >> You received this message because you are subscribed to a topic in 
> > >> the Google Groups "BeagleBoard" group. 
> > >> To unsubscribe from this topic, visit 
> > >> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe. 
>
> > >> To unsubscribe from this group and all its topics, send an email to 
> > >> beagleboard+unsubscribe-/JYPxA39Uh5TLH3MbocFF 
> > >

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Richard,

Please see the post
http://blog.lemoneerlabs.com/post/BBB-webcamsconcerning the PS3Eye,
C920, and frame rates.  I believe it will answer
your questions.


On Tue, Sep 24, 2013 at 12:50 PM, rh_  wrote:

> On Mon, 23 Sep 2013 01:48:18 -0700
> Michael Darling 
> wrote:
>
> > I have confirmed that it is indeed possible to grab AND convert
> > frames at 640x480 and 30 fps with the BBB and Logitech C920 operating
>
> The ps3 eye could not do this or have you tried yet?
>
> > in MJPEG mode. My solution was to basically install libjpeg-turbo
> > from source with NEON enabled and then building and installing OpenCV
> > from source, using libjpeg-turbo as the JPEG codec. I also built
> > OpenCV with NEON enabled.
> >
> > Here is sample output with every frame being processed. The 'top'
> > utility shows about 50% CPU and only about 2% memory usage. Before
> > executing the code, I set the CPU to operate at constant 1Ghz using
> > "sudo cpufreq-set -g performance" so that there isn't a "slow start"
> > while the BBB starts grabbing frames at 300 Mhz before it finally
> > kicks into 1Ghz under load.
> >
> > time ./framegrabber -f mjpeg -H 480 -W 640 -c 1000 -I 30 -o
> > Startup took 0.00 seconds
> > Captured 1000 frames and Processed 1000 in 13.94 seconds
> > Shutdown took 0.01 seconds
> >
> >
> > real0m33.760s
> > user0m11.566s
> > sys0m2.518s
> >
> > I ended up using distcc to do a distributed cross-build of OpenCV on
> > my PC, but still had problems with running out of space trying to
> > store all of the source and object files on the 2GB eMMC on the BBB.
> > I ended up having to mount an ext2 formatted filesystem using a USB
> > thumb drive hooked up to the BBB and building OpenCV from there.  I
> > probably ended up doing a lot of extraneous things that had little to
> > no effect but I do have a working process for those who need to get
> > 30 fps.  I need to go back and clean up some notes I took and then I
> > plan to post a step-by-step guide for anybody else who wants to
> > replicate what I did.
>
> Will you say what the application is? Or at least is it a stationary
> camera? Or is it something like for robot vision?  Using that Motion
> app (mentioned previously) would get higher frame-rate, I think.
> Unless Motion is post-processing. I'm sure not all USB cams are
> created equal. But I wonder how much can be done via USB.
> Seems to me that image substraction (or whatever the correct term)
> would probably need to happen at the hardware level to get any
> capture rate increase. So maybe there's no way to get a higher
> frame rate due to hardware limitations.
>
> >
> > Thanks,
> > -Mike
> >
> >
> > On Sat, Sep 21, 2013 at 4:48 PM, Matthew Witherwax
> > wrote:
> >
> > > Jon,
> > >
> > > I hope you find it useful.  I would appreciate any feedback you
> > > have to give.
> > >
> > > Best of luck,
> > > Matthew
> > >
> > >
> > > On Sat, Sep 21, 2013 at 4:54 AM,  > > +bqq9rb...@public.gmane.org> wrote:
> > >
> > >> Matthew,
> > >>
> > >> Thanks! That may be really useful for me. Am messing around with a
> > >> PTZ camera at the moment, and lag in the video stream has been a
> > >> bit of a problem so far..
> > >>
> > >> Regards,
> > >> Jon
> > >>
> > >>
> > >> On Friday, 20 September 2013 14:01:23 UTC+1, Matthew Witherwax
> > >> wrote:
> > >>>
> > >>> William,
> > >>>
> > >>> I have posted my streaming code and writeup here
> > >>> http://blog.lemoneerlabs.com/**post/bbb-mjpeg-streaming<
> http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming>
> > >>>
> > >>>
> > >>>  --
> > >> For more options, visit http://beagleboard.org/discuss
> > >> ---
> > >> You received this message because you are subscribed to a topic in
> > >> the Google Groups "BeagleBoard" group.
> > >> To unsubscribe from this topic, visit
> > >> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe
> .
> > >> To unsubscribe from this group and all its topics, send an email to
> > >> beagleboard+unsubscribe-/JYPxA39Uh5TLH3MbocFF
> > >> +G/ez6zc...@public.gmane.org For more options, visit
> > >> https://groups.google.com/groups/opt_out.

Re: [beagleboard] Re: problems with webcams

[Matthew Witherwax]

Mike,

I look forward to your write up.  I am glad to hear distcc worked for you.
A note about the files to put on the BBB, you should really only need the
compiled libs and the header files.  The build I did on my surface
(Windows) created a directory called install that has a lib and an include
directory with a total size of ~10 MB.  I would imagine the build for Linux
would be close to that.


On Mon, Sep 23, 2013 at 3:48 AM, Michael Darling wrote:

> I have confirmed that it is indeed possible to grab AND convert frames at
> 640x480 and 30 fps with the BBB and Logitech C920 operating in MJPEG mode.
> My solution was to basically install libjpeg-turbo from source with NEON
> enabled and then building and installing OpenCV from source, using
> libjpeg-turbo as the JPEG codec. I also built OpenCV with NEON enabled.
>
> Here is sample output with every frame being processed. The 'top' utility
> shows about 50% CPU and only about 2% memory usage. Before executing the
> code, I set the CPU to operate at constant 1Ghz using "sudo cpufreq-set -g
> performance" so that there isn't a "slow start" while the BBB starts
> grabbing frames at 300 Mhz before it finally kicks into 1Ghz under load.
>
> time ./framegrabber -f mjpeg -H 480 -W 640 -c 1000 -I 30 -o
> Startup took 0.00 seconds
> Captured 1000 frames and Processed 1000 in 13.94 seconds
> Shutdown took 0.01 seconds
>
>
> real0m33.760s
> user0m11.566s
> sys0m2.518s
>
> I ended up using distcc to do a distributed cross-build of OpenCV on my
> PC, but still had problems with running out of space trying to store all of
> the source and object files on the 2GB eMMC on the BBB.  I ended up having
> to mount an ext2 formatted filesystem using a USB thumb drive hooked up to
> the BBB and building OpenCV from there.  I probably ended up doing a lot of
> extraneous things that had little to no effect but I do have a working
> process for those who need to get 30 fps.  I need to go back and clean up
> some notes I took and then I plan to post a step-by-step guide for anybody
> else who wants to replicate what I did.
>
> Thanks,
> -Mike
>
>
> On Sat, Sep 21, 2013 at 4:48 PM, Matthew Witherwax wrote:
>
>> Jon,
>>
>> I hope you find it useful.  I would appreciate any feedback you have to
>> give.
>>
>> Best of luck,
>> Matthew
>>
>>
>> On Sat, Sep 21, 2013 at 4:54 AM,  wrote:
>>
>>> Matthew,
>>>
>>> Thanks! That may be really useful for me. Am messing around with a PTZ
>>> camera at the moment, and lag in the video stream has been a bit of a
>>> problem so far..
>>>
>>> Regards,
>>> Jon
>>>
>>>
>>> On Friday, 20 September 2013 14:01:23 UTC+1, Matthew Witherwax wrote:
>>>>
>>>> William,
>>>>
>>>> I have posted my streaming code and writeup here
>>>> http://blog.lemoneerlabs.com/**post/bbb-mjpeg-streaming<http://blog.lemoneerlabs.com/post/bbb-mjpeg-streaming>
>>>>
>>>>
>>>>  --
>>> For more options, visit http://beagleboard.org/discuss
>>> ---
>>> You received this message because you are subscribed to a topic in the
>>> Google Groups "BeagleBoard" group.
>>> To unsubscribe from this topic, visit
>>> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
>>> To unsubscribe from this group and all its topics, send an email to
>>> beagleboard+unsubscr...@googlegroups.com.
>>> For more options, visit https://groups.google.com/groups/opt_out.
>>>
>>
>>  --
>> For more options, visit http://beagleboard.org/discuss
>> ---
>> You received this message because you are subscribed to a topic in the
>> Google Groups "BeagleBoard" group.
>> To unsubscribe from this topic, visit
>> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to
>> beagleboard+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>
>  --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/G5Xs2JuwD_4/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> beagleboard+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to beagleboard+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.