OLIMEX© 2017
A20-OLinuXino-LIME2 user's manual
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-
– 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 GitHib page:
https://github.com/OLIMEX/OLINUXINO/tree/master/SOFTWARE/A20
Another useful place is the Olimex forums where a lot of people share their experience and advice:
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 Linux or Android
software support.
We can share our experience. We can give you full details for things we have tried. We can point you to a
resource or a guide. We can give you general directions to solving a specific problem or places to look for
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