Hi,
I have the save problem. I'm writing 2 bytes to an external device over SPI
and i'm waiting for one byte response.
I saw on the scope that the device send the response on the MISO, but i
can't read it with spidev.
i'm using one transfert struct for full duplex commnication and i'm waiting
Hi Jan,
Thanks for your answer.
1)
SPI_MODE :
I am currently using the SPI_MODE_1 so it seems ok (CPOL = 0x02 | CPHA =
0x01 == 0x01)
I have also a MODE0 in my device tree file :
spi0_pins_s0: spi0_pins_s0 {
pinctrl-single,pins =
0x150 0x10 /*
Hi,
1) I said your clock should not be much higher than the maximum clock, that
a device can handle. It can be anything within the range. You are OK with
1MHz, no need to change it.
SPI mode and pin mode on BBB are 2 different things, you are OK here as
well.
2) Your software calls to IOCtl
Saisissez le code ici...
Hi Jan,
Ok so I have done some progress I am almost done. My last issue is purely a
software issue.
So first I found a first issue which was due to bad voltage. I was
supplying my slave thanks to the Beaglebone Black. I need a voltage of 5V
delivered by the VDD_5V.
Hi Artur,
Sorry to hear, you have problems, but usually there is something very
simple, that you might be doing wrong:
1) Check you SPI setting. For your device you need CPOL=0 and CPHA=1 - see
page 8 of http://www.ti.com/lit/ds/symlink/ads1299.pdf and the max freq of
master clock 444ns -
Hi Jan,
Ok so your first advice was really good. I can see that I was not able to
run a simple loopback between the D1/D0 pin on the board; So I conclude
that the problem come from the wire. I was pretty sure about the
configuration and software part.
So I finally change the jumper/wire used
Ok but how can I know the setup associated to the dtbo files ? Is there any
reverse engineering to get the dtc file from the dtbo ? I want to
comunicate by SPI0 so I guess that I have to choose ADAFRUIT-SPI0-00A0.dtbo
or BB-SPIDEV0-00A0.dtbo. How do I choose ? How can I know if D0/D1 is an
Hi Jan,
So I put a simple wire between pin 18 and 21 and try to run the
spidev_test... Same result... FF only I also check with an
oscilloscope. I see nothing... I am not able to see my data.
root@beaglebone:~# ./spidev_test -D /dev/spidev1.0
spi mode: 0
bits per word: 8
max speed:
Hi Arthur,
BBB is a very time consuming hobby.
Take it ease, relax, go for a walk and when you return, try:
1) try your project as root
if no luck follow my (working) path
2) Try to repeat my settings and see if it works for you.
I wasn't able to build the original Linux spidev_test, so...
The two devices that show up are associated with the same clock and data
lines, they just have different chip select lines to allow you to multiplex
two devices -- they cannot be used simultaneously.
On Mon, Nov 10, 2014 at 3:54 PM, janszymanski12...@gmail.com wrote:
Hi,
Following the links:
...so if you enable both spidevs you have four devices show up.
On Tue, Nov 11, 2014 at 9:51 AM, Jason Lange j.b.la...@gmail.com wrote:
The two devices that show up are associated with the same clock and data
lines, they just have different chip select lines to allow you to multiplex
two
Hi,
Following the links: http://elinux.org/BeagleBone_Black_Enable_SPIDEV and
http://www.nagavenkat.adurthi.com/2014/02/spi-communication-beaglebone-black-as-master-to-arduino-as-slave/
I was able to make it work, but I have a SS too long (1.4ms) for my need.
For easy test connect MOSI and
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