Gpio Expansion Header 2

Hi there,

Is it possible to control the Gpio Pins on the expansion header 2? I found nothing on the internet to this question.
On the expansion header 1 there are only 8 Gpios but i need a few more, what can i do?

Thanks a lot

Benedikt

Do you mean J21 and J26? The silkscreen should show that numbering in tiny print next to the connector.

Pins differ between for a Jetson TK1 versus a TX1 (TX1 also has more GPIO); pins are the same between TX1 and TX2 (some “/sys” and “/proc” files may differ, but they use the same carrier board). Some general information:
http://elinux.org/Jetson/GPIO
http://elinux.org/Jetson/Tutorials/GPIO

For conenience, when searching for files in “/sys” which may be different from the board the tutorial or other reference refers to:

# Find directory in "/sys" named "gpio":
sudo find /sys -type d -name 'gpio'

In the kernel source you may find some mappings of how the GPIO are numbered in the kernel versus how they are named in the Technical Reference Manual (TRM):

arch/arm/mach-tegra/gpio-names.h

You may want to create a free login if you have not done so already, and log in here:
https://developer.nvidia.com/embedded/downloads

…check the TX1 box, then enter search term “Technical Reference”.