pinNameToGPIO

BeagleBoard. Find the GPIO file associated to a given pin-name, like P9_14

Mini documentation

Problem description

It often happens that we want to use a pin as a digital input/output pin, that is a gpio. To do so first you need to say to the beagleboard the pin is a GPIO. You can do it do using config-pin then, you need to know which file in the filesystem has been associated to the GPIO, that is, you need to establish the XXX value in /sys/class/gpio/gpioXXX. There is a formula to do that, but its is different between the BB-Black and the BB-AI also, it does not always work: e.g. in BB-AI for P9_11 to me it fails. Therefore I give us this script which should solve the problem once and for all.

Example

We know pin P9_14 is set to gpio, what is its associated file in sysfs ?
You run:

$> pinNameToGPIO.py P9_14

In my system I get as output /sys/class/gpio/gpio121, your output may be different.
If you get no output it means the associated file was not found i.e. the system thinks the pin you selected isn't a GPIO pin.
You can write the pin name as P9_14 or P9.14 and it is case insensitive.

Tested working in

02-dec-2021. BB-AI, BeagleBoard.org Debian Buster IoT Image 2021-10-01, Linux BB-AI-1 4.19.94-ti-r68 #1buster
03-dec-2021. BB-Black, BeagleBoard.org Debian Buster IoT Image 2020-04-06, Linux beaglebone 4.19.94-ti-r42

ATTENTION !!

The BeagleBoard world moves fast, always check:
- Your board name
- Your operating system version

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