MP34DT05 PDM on ESP32

[Mukhin22]

Hey Phil!

Is it possible to use #include "AudioLibs/AudioMP34DT05.h" like this example:
examples/examples-stream/streams-mp34dt05-serial/streams-mp34dt05-serial.ino
for esp32 not Arduino Nano?

Because when I'm trying to start it with my esp32 board on Arduino IDE "PDM.h" file used in the "AudioLibs/AudioMP34DT05.h" does not indexed properly.

Or can you recommend some other example of such a PDM mic usage for esp32 with your beautiful libs

[Mukhin22]

I have tried with such configuration just with basic I2S api, but it doesn't seem to work - just noisy crackles. (double and triple checked all hw connections).

info_micro.channels = 2;
info_micro.sample_rate = 44100; // tried with 16000 - same
info_micro.bits_per_sample = 16;
/* Configure and start the input i2s */
auto i2s_input_config = i2s_input.defaultConfig(RX_MODE);
i2s_input_config.signal_type = audio_tools::PDM;
i2s_input_config.copyFrom(info_micro);
//i2s_input_config.i2s_format = I2S_STD_FORMAT;
i2s_input_config.is_master = true;
i2s_input_config.port_no = I2S_MICRO_PORT;
i2s_input_config.pin_bck = I2S_MICRO_BCK_PIN;
//i2s_input_config.pin_ws = I2S_MICRO_WS_PIN;
i2s_input_config.pin_data = I2S_MICRO_DATA_PIN;
i2s_input.begin(i2s_input_config);

[pschatzmann]

I don't have any experience with the MP34DT05 PDM on the ESP32.
You will really need to find some working examples using and based on this we can determine the necessary settings to my API

[Mukhin22]

I think main problem is I'm trying to use PCB with ESP32-PICO-MINI-02. And there is no appropriate target for this board on Arduino IDE. Because I can't see the clock pulses both with ESP32-PICO-D4 and ESP32-WROOM-32DU targets with logic analyzer.
Do you know some workarounds how to run detect proper pin, if there is no target for such ESP32?

[Mukhin22]

What's about examples, I've found smth that should work https://github.com/RafigRzayev/Audio_Recording_to_WAV/blob/main/pdm_mic/pdm_mic.ino.
But I think I have to resolve proper target issue first.

[pschatzmann]

If I work with a processor which is not in the list I always use the ESP32 Dev Module.
If the example is working you will need to double check if it is still working if you change I2S_CHANNEL_FMT_ONLY_RIGHT to I2S_CHANNEL_FMT_RIGHT_LEFT since I don't support this parameter in your installed version.

[pschatzmann]

Here you can find some additonal info: https://esp32.com/viewtopic.php?t=6062
Looks like you need to define the channel_format and that the wiring (pin assignments) is a bit unexpected!

[pschatzmann]

I updated the documentation: https://github.com/pschatzmann/arduino-audio-tools/wiki/External-ADC

[Mukhin22]

Thanks, I got it working more or less, part of the problem was hardware, now need to figure out if sound quality is good. It's not so easy because use case is micro+a2dp sound coming to speaker and they're very close to each other.
I'll check your documentation.