Howdy Cheryl,


Scott’s GPIO page is the best I’ve come across for gumstix:


You can also see some of this stuff in the wiki:


RE your shell stuff – the logic level of the pins is only 1.8V, keep that in mind when making measurements.  I can toggle the level of gpio_10 using the first three commands you posted without any trouble.   That’s using kernel 2.6.36-r100 with u-boot 2010.09. 






From: Cheryl Skibski []
Sent: Tuesday, 14 June 2011 11:31 AM
Subject: [Gumstix-users] Setting a GPIO pin high on Gumstix Overo Fire


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 prompts: 

echo "10">/sys/class/gpio/export 
echo "out">/sys/class/gpio/gpio10/direction 
echo "1">/sys/class/gpio/gpio10/value 
Measured with an oscilloscope using PIN 15 as GND 
echo "in">/sys/class/gpio/gpio10/direction 
echo "o">/sys/class/gpio/gpio10/value 
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 high. 

For the python code I figured I would be doing something according to these steps to make the pin high: 
open /sys/class/gpio/gpio10/value 
write a 1 to the value 

Thanks in advance