No voltage on GPIO dragonboard 410c

Products Support DragonBoard410c
#1

I set pin 23 on the low speed expansion of my Dragonboard 410c which is GPIO 36 on Debian, direction as “out” and value as “1” through the command line. However, when measuring the voltage, I get 0V. Toggling the value does not do anything.
Additionally, testing a few other GPIO pins also has the same result - no voltage is outputted.

image
image700×207 41.1 KB

Note: GPIO418 comes from 386+36=418

This 0V is measured with respect to the ground pins on the board. Also, the 5V and 1.8V power on the pins 35 and 37 are working, so how can I get the GPIO pins to work?

#2

I found the issue, the correct number to export on debian for me was 426
echo 426 > export
This is because 390+36 = 426
(390 is from “gpiochip390”)
Not sure why this was the correct value but it works now

#3

You should install and use gpiod instead, which should be easier for locating the right pin.