ECE497 Notes on gpio-keys

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thumb‎ Embedded Linux Class by Mark A. Yoder


Timers

Here's some leads on using timers.

kunen.org

gpio-keys

I'm trying to figure out how to access the USER button on the Beagle xM. It looks like the new versions of the SD image use gpio-keys to manage gpio 4 so you can't access it via

beagle$ cd /sys/class/gpio
beagle$ echo 4 > export
bash: echo: write error: Device or resource busy

You need to access it via evtest, but I don't see a way to do it via the shell.

References

  • Here Jason suggests looking at evtest.c to learn how to access the USER button.
  • Here are some details on evtest.




thumb‎ Embedded Linux Class by Mark A. Yoder