Hello everyone,
I am a total newbie to pythonUSB.
I am using the PyUSB interface for one of the devices which has a FTDI chip.
I could read the device ID and get the serial number of it.
I need to read and write data to the device.
The example provided on the website is not sufficient to read or write data.
Could you provide some examples which i could try out so that i can talk
with the device?
I have refered the programmers guide for D2XX programming but it seems to be
written for C programming.
I tried to modify to suit to a python environment.
For eg, in the code below:
# ----------
# import the PyUSB module
import d2xx
global EventDword,TxBytes,RxBytes,
BytesReceived
EventDword =TxBytes=RxBytes=BytesReceived=0
# list devices by description, returns tuple of attached devices description
strings
d = d2xx.listDevices(d2xx.OPEN_BY_DESCRIPTION)
print d
# list devices by serial, returns tuple of attached devices serial strings
d = d2xx.listDevices() # implicit d2xx.OPEN_BY_SERIAL_NUMBER
print d
h = d2xx.open(0)
print h
# get queue status
print h.getQueueStatus()
# set RX/TX timeouts
h.setTimeouts(1000,1000)
print h.read(5)
# ----------
The python interpreter exits once it reaches print h.read(5).
I need read data from the device and write to it as well.
The device is data acquisition system which is connected to the PC via a
USB cable.
The output received for execution of the code till it reaches the Read is as
below:
>> ('USB Interface IF-U1',)
>>> ('EAT2QBD0',)
>>> <FtobjType object at 0x00A17300>
>>> 0
[Dbg]>>>
This tells me that i am connected to the device and get the object of it.
But i need to use it and read and write data from the device as well.
Any help in this regard is highly appreciated.
Regards
Karthik
On 22 December 2010 01:51, Andrew Errington <a.erring...@lancaster.ac.uk>wrote:
> On Wed, December 22, 2010 05:50, Tormod Volden wrote:
> > On Tue, Dec 21, 2010 at 1:36 PM, Andrew Errington wrote:
> >
> >> code and a compiled binary. Unfortunately the binary was compiled for
> >> a different Product ID than the device I have. Doubleplus unfortunately
> >> the source code for the .lib file which actually sends the data packets
> >> to the device is already compiled. I have the header file, but not the
> >> source.
> >
> > If only the Product ID is wrong (but the code would otherwise work
> > with your device) I would have tried binary patching to change the ID. If
> > you know the ID it is built for and can do some disassembly, you might
> > have a chance to find the right bytes to patch.
>
> Yes, it's a good idea, thank you. I did think about this already, but I
> can not be sure that the Product ID in the compiled code is the same as
> the sample source code. Probably it is, but even so, it is a 16-bit
> value, and I don't know if it will be encoded as two bytes together. If I
> cannot find a compiler then I will try to hack the binary.
>
> Best wishes,
>
> Andrew
>
>
>
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--
Thanks and Regards,
Karthikeyan.V
Transmission Controls HIL LAB
Tel: +44 (0)2476 206717
kvenk...@jaguarlandrover.com <g...@jaguarlandrover.com>
Land Rover, Banbury Road, Gaydon, Warwick, CV35 ORR, UK. Registered in
England and Wales Number: 4019301.
Jaguar Cars Limited, Abbey Road, Whitley, Coventry, CV3 4LF, UK. Registered
in England Number: 1672070.
------------------------------------------------------------------------------
Forrester recently released a report on the Return on Investment (ROI) of
Google Apps. They found a 300% ROI, 38%-56% cost savings, and break-even
within 7 months. Over 3 million businesses have gone Google with Google Apps:
an online email calendar, and document program that's accessible from your
browser. Read the Forrester report: http://p.sf.net/sfu/googleapps-sfnew
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