Difference between revisions of "ECE497 Notes on gpio-keys"

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== Timers ==
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Here's some leads on using timers.
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[https://groups.google.com/forum/?fromgroups#!topic/beagleboard/lCagocQaKiY%5B1-25%5D kunen.org]
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== 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
 
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$ '''cd /sys/class/gpio'''

Revision as of 12:17, 13 August 2012

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