I’m trying to play audio out the I2S1 interface (or any interface for now), but the SDOUT pin doesn’t seem to send any data. I’m using aplay (with no arguments except for the source audio file). When aplay starts, I can see the MCLK start running, along with SRCLK and SFSYNC (all available on J21), however SOUT does not have any data. It just stays low. Running aplay with -vv clearly shows that it should be sending data.
Is this the expected behavior? Am I missing a step?
I’m running this on a virgin TX2 our of the box (after running the initial install script). I have tried the same command on a TX1 with the latest jetpack kernel and nothing at all happens on any of the I2S pins (no clock or data at all). I also tried this on a TX2 with the jetpack kernel, and it acted like the TX1 (no output at all).