I2C & GPIO Expansion

How do we register and use the GPIO expansion.
Using Ubuntu 18.04 LTS and I2C 0 is connected to GPIO expansion using TCA9535. How I do access the GPIO pins on the expansion board?
I’m using Python3 for all GPIO development.

hello aidev,

you may use Jetson-IO tool to simplify the configuration, please check Configuring the 40-Pin Expansion Header.

Hello @JerryChang,
Should I be selecting AdaFruit SPH? I’m using TCA9535? And I dont see that listed in the 40 pin expansion header screen?

hello aidev,

please also refer to NVIDIA Jetson Xavier NX GPIO Header Pinout,
you may have configuration for compatible hardware,

I’m sorry I don’t follow this. I have the GPIO expansion with about 17 GPIO elements and the GPIO Header Pinout only goes till 13. How would I configure it to use/expand to 17 or more GPIO’s
On the relay board, I have 17 GPIO and 40-pin for sound, 1 i2c for temp and 17 pin gpio. So all this needs to be read through the i2c bus?

hello aidev,

please check pinmux spreadsheets through download center.
some of pins did not assign as GPIO, there’s pin configurations you may have modify in the [Customer Usage] field,
please also refer to developer guide, Pinmux and GPIO Configuration.