Cannot control GPIO pins through /sys/class/gpio


I try to access the GPIO pins thorugh /sys/class/gpio to write values to them. Later, I want to construct a C++ program for that, but for now I try by hand through the console. Here are, for example, my commands to output a HIGH on pin 19:

$ sudo su
# echo "16" > /sys/class/gpio/export
# echo "out" > /sys/class/gpio/gpio16/direction
# echo "1" >/sys/class/gpio/ gpio16/value

I followed a simple Raspberry Pi tutorial for this and hoped this would work since the GPIO structure is pretty much the same as by Jetson Nano, but it doesn’t. I measured with an oscilloscope and there’s no voltage at all on the pin, despite the fact that no error messages are given. I tried different pin numberings, too, but the sysfs gpio numbering should theoretically be correct.

What am I doing wrong? Can you even do it that way? Can someone link me a proper pinout diagram for Jetson Nano (because I found none)?

EDIT: I looked at the status of the GPIO pins during the above process with $ cat /sys/kernel/debug/gpio, and it really states that HIGH is outputted at pin 16, but again, measuring with oscilloscope confirms there is no actual current flowing. Where could the problem lie then?

hello nemestomi2,

pin-19, SPI_1_MOSI has configure to GPIO pin, GPIO3_PC.00, its direction as input by default.
you may access pinmux spreadsheets via download center, please modify the “customer usage” to have customization.
you may refer to documentation, Pinmux changes session for the steps of pinmux customization.
or, you could check Configuring the 40-Pin Expansion Header to have configuration with Jetson-IO python tools.