This repository is mainly meant as a companion for a JetsonHacks article about SPI. Requires JetPack 4.3+ (L4T 32.3.1+).
Directions here are for a Jetson Nano running JetPack 4.3
In the default configuration on all Jetsons in JetPack 4.3, several of the GPIO pins which can be used to represent specialized functions (SFIO) are configured as GPIO. The tool jetson-io provides a user interface to help configure the pins.jetson-io builds a device tree overlay from user input, and applies it to the device tree. In version JetPack 4.3 (L4T 32.3.1), there are a couple of issues. Here is the documentation page:
From the instructions, first fix the init functions:
$ sudo find /opt/nvidia/jetson-io/ -mindepth 1 -maxdepth 1 -type d -exec touch {}/__init__.py \;
If you are using a Jetson Nano and JetPack 4.3, there is an additional step needed that is not documented in the above document. If you are using a Jetson Nano, copy the dtb file for the Nano to /boot/dtb
$ sudo mkdir /boot/dtb
$ sudo cp -v /boot/tegra210-p3448-0000-p3449-0000-[ab]0[012].dtb /boot/dtb/
Now you are ready to run to jetson-io tool. From a Terminal (the window should be maximized to be able to see the entire menu context):
$ sudo /opt/nvidia/jetson-io/jetson-io.py
You will now be able to configure the SPI ports. Remember to save your assignments, and reboot the machine to take effect.
In the 'examples' folder, there are sample Python scripts to run an Adafruit ST7735 based display.For how to use the examples, see the 'README.md' file in the examples folder. April, 2020- JetPack 4.3, L4T 32.3.1
- Jetson Development Kits
- Tested on Jetson Nano Development Kit