User manual

2.2 Set output:

echo "out" > /sys/class/gpio/gpio49_ph9/direction

3. Set value or read value GPIO 49

3.1 Set value:

echo 0 > /sys/class/gpio/gpio49_ph9/value

echo 1 > /sys/class/gpio/gpio49_ph9/value

3.2 Read input:

cat /sys/class/gpio/gpio49_ph9/value

4. Unexport GPIO 49 when finished

echo 49 > /sys/class/gpio/unexport

A helpful document on A20's GPIO usage might be found here:

http://www.py6zgp.com/download/A20-GPIO.pdf – the document was created by Dr. Guido Pelz.

Alternatively, you might also use the Python script mentioned in the next chapter.

2.9 I2C and SPI under Debian

I2C and SPI are both supported in the latest Debian releases. There is a python module called

pyA20Lime2, which also might be found here: https://pypi.python.org/pypi/pyA20Lime2

At the same web address you would also find information on how the library is used.

2.10 Software support

We maintain Linux and Android images for SD card which might be downloaded for free and

modified as the user wishes. The latest images and updates are featured at the wiki article of the

device: https://www.olimex.com/wiki/A20-OLinuXino-LIME2.

We usually try to provide details on how to build the Linux and the Android images at our

wordpress page: http://olimex.wordpress.com/.

Another useful place is the Olimex forums where a lot of people share their experience and advice:

https://www.olimex.com/forum/

The official images are a constant work-in-progress – newer releases are packed with better

hardware support, newer kernels and extra features.

You are more than welcome to send or share your suggestions and ideas at our e-mail, the public

forums or irc channel. We would attempt to help in almost every case. We listen to the feedback and

if the majority of users suggest a software change or update we try to implement such. Customer

feedback is very important for the overall state of the software support. However, do not expect full

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