There are two known issues in L4T release 32.3.1 which prevent Jetson‑IO from working correctly:
•Launching Jetson‑IO fails with the following error:
$ sudo /opt/nvidia/jetson-io/jetson-io.py
Traceback (most recent call last):
File “/opt/nvidia/jetson-io/jetson-io.py”, line 25, in
from Jetson import board
ImportError: cannot import name ‘board’
To resolve this issue, enter the following command:
$ sudo find /opt/nvidia/jetson-io/ -mindepth 1 -maxdepth 1 -type d -exec touch {}/init.py ;
•After L4T on Jetson Nano is upgraded to release 32.3.1 using the SD card image, launching Jetson-IO fails with the error message ‘No DTB found for NVIDIA Jetson Nano Developer Kit!’.
To resolve this issue, enter the following commands:
$ sudo mkdir /boot/dtb
$ sudo cp -v /boot/tegra210-p3448-0000-p3449-0000-[ab]0[02].dtb /boot/dtb/
I have successfully ran this solution on my JetPack 4.2. Now
ls /dev | grep spi
shows the following output:
spidev0.0
Does this mean my SPI is ready to go (for example, with the test program linked to by ShaneCCC) or do I need to perform any more checks to make sure it is? If so, what else do I need to ascertain?
You can have Loopback Testing to check it. Have a reference to below link.
https://elinux.org/Jetson/TX1_SPI#Loopback_Testing
Thanks a lot! I’ve just run this test successfully. In conclusion, running the solution by gtjoseph was the only SPI-related change I had to make in the my system in order to get the satisfactory output from the SPIDev Test.
Tried now this loopback test on JetPack 4.3 and am reading zeros. Pins 19 and 21 on J41 header are connected. /dev/spidev0.0, -0.1, -1.0 and -1.1 are present in the system, the loopback test shows no data through either. sudo cat /sys/kernel/debug/tegra_gpio shows 00 in row C, indicating that the SPI pins are muxed to the SPI function. What has to be done on an out-of-the-box JetPack 4.3 to get SPI to work?