Esp-idf: i2s_read with external I2S microphone always returns zero (IDFGH-1805)

[morganrallen]

I've spent weeks trying dozens of variation but cannot seem to get i2s_read to return anything but zeros when reading from ICS-43434. My code is very similar to an ESP32 Arduino 1.0.2 example that works, and even if I use i2s_read_bytes to match it even more closely I cannot get it to work, which has me wondering if newer versions of the IDF have a bug related to external I2S inputs.

Environment

• Development Kit: https://www.tindie.com/products/microwavemont/esp32-simple-alexa/
• Module or chip used: ESP32-WROVER
• IDF version: v4.0-dev-1443-g39f090a4f
• Build System: CMake
• Compiler version: 1.22.0-80-g6c4433a
• Operating System: Linux
• Power Supply: USB

Problem Description

i2s initialization goes as expected but when i2s_read, or i2s_read_bytes are called, they always return zero.

Expected Behavior

Get non-zero response

Actual Behavior

Zeros

My test case that does not work against the IDF listed above.
https://gitlab.com/morganrallen/i2s-test-case
Although this code when compiled against Arduino ESP32 1.0.2 works as expected.
https://github.com/maspetsberger/esp32-i2s-mems/blob/master/examples/VUMeterDemo/VUMeterDemo.ino

[Alvin1Zhang]

@morganrallen Thanks for reporting the issue, we will look into it.

[amirgon]

I see the same problem.

[koobest]

Hi, @morganrallen
If the DIN pin is connected to vcc, is the read data still 0?

thanks !!

[leleb]

Me too having this issue after rebuilding an old working project.
for the moment I solved rolling back to espressif platform version 1.9.0.
In platform.ini set:
platform = [email protected]
using later platforms (1.10.0 or 1.11.0 or latest 1.11.1) makes my I2S microphone not working.

[leleb]

Solved: using latest platform must swap left and right channel in configuration structure
i2s_config_t i2s_config = {
...
.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
...

while in older platform works using I2S_CHANNEL_FMT_ONLY_RIGHT