I am confused by a strange I2S phenomenon with the Jetson Nano Developer Kit B01.
How to reproduce:
- write JetPack 4.6.1 to SD card, boot and initial setup for terminal
- run sudo apt update && sudo apt upgrade in terminal
- Enable aud_mclk, i2s4 using jetson-io.py and reboot
- arecord -D hw:tegrasnd210ref,0 -f S24_LE > /dev/null
- Check the clock output of Pin12 I2S4_SCLK
The first arecord outputs SCLK, but when arecord is run again after reboot, the SCLK clock is not output. It never comes out again.
Four new Developper Kit had the same phenomenon.
The phenomenon did not occur without apt upgrade (prodecure 2) on another new Developper Kit.
However SCLK does not come out even if use SD that has not been apt upgraded once I2S stops working.
No SCLK, but software operation appears to be fine.
Does the latest package apt upgrade break I2S?