PDM Tx Available in ESP32-S2?
Posted: Sat Jan 30, 2021 2:51 am
Hello, I have just got an ESP32s2 dev board, and trying to port an old ESP32 project which uses I2S0 PDM tx mode (which is essentially a free 16-bit single channel delta-sigma DAC 
) to play audio. I was thinking that the I2S on ESP32s2 is similar to the I2S0 on ESP32, however, I soon realized that the current I2S driver doesn't take the I2S_MODE_PDM bit in. I also couldn't find any references of PDM Tx/Rx in the TRM. I wonder if it is the driver and documentation haven't caught up, or the function has been removed in S2.
BTW, while the PDM out worked amazingly on ESP32, the driver support for it could be better. It doesn't work with APLL out of the box. I need to modify a few driver files to make the clock calculation right with APLL.
) to play audio. I was thinking that the I2S on ESP32s2 is similar to the I2S0 on ESP32, however, I soon realized that the current I2S driver doesn't take the I2S_MODE_PDM bit in. I also couldn't find any references of PDM Tx/Rx in the TRM. I wonder if it is the driver and documentation haven't caught up, or the function has been removed in S2.BTW, while the PDM out worked amazingly on ESP32, the driver support for it could be better. It doesn't work with APLL out of the box. I need to modify a few driver files to make the clock calculation right with APLL.