On 14/06/2011 11:31 AM, Cheryl Skibski wrote:
I am a graduate student working on a project with the Gumstix
Overo Fire and Tobi Expansion Board. This is my first time
working on a Linux embedded computing project ever so help would
be much appreciated.
My task is to create a python code for a GPIO (I was planning on
GPIO10). This code will turn the pin high to have a voltage
output and then turn the pin low.
I was doing some testing in the command line with the following
Measured with an oscilloscope using PIN 15 as GND
Measured with an oscilloscope
I saw no change when measuring both times.
I have been reading multiple forums and all of them seem
confusing and complicated. All I want to do is turn the pin
For the python code I figured I would be doing something
according to these steps to make the pin high:
write a 1 to the value
Thanks in advance
why change the direction in the middle ?
Have you set the pinconf register using devmem2
devmem2 register_address word/halfword value
devmem2 0x480021E2 h 0x10c
Processor: Technical Reference Manual, Chapter 7 - Tables 7.4, 7.5
and 7.6, at http://focus.ti.com/lit/ug/spruf98r/spruf98r.pdf
to check for the correct register address
Have a careful read of Scotts page on gpio
I've made some quick c versions of the code on his page
Its fairly trivial to either convert the bash or the c code to
I'd suggest using subprocess for the system calls
self.cmd0 = "devmem2 0x480021E4 h 0x10c"
self.process = subprocess.Popen(self.cmd0, stdout=subprocess.PIPE ,
self.udata = self.process.stdout.read().strip()
Then open and close with exception handling to talk to sysfs for
accessing the values.
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