Support for External PDM Microphones on the Arduino BLE 33 (did not include built-in microphone)?

Hi everyone,

I had a question regarding how to use a PDM microphone (Adafruit DM Microphone Breakout with JST SH Connector) on my Arduino BLE 33. My particular Arduino did not come with the built-in PDM microphone of the BLE 33 Sense, but I bought an external PDM microphone to compensate.

Up until now, the standard PDM library has not worked, with the following pinout:

  • Adafruit Microphone DAT -> Arduino BLE I2C SDA
  • Adafruit Microphone CLK -> Arduino BLE I2C SCL
  • Adafruit VDD -> Arduino BLE 3.3V
  • Adafruit GND -> Arduino BLE GND

I also tried to use the Adafruit Zero PDM library, but it comes up with:
Error compiling for board Arduino Nano 33 BLE

Is there a way that I can make use of this microphone (or any other external microphone) without having to hard-wire to the PDM solder pads?

This is a good question, mine is similar:

I bought a Sense board so I can experiment with Picovoice.AI voice control, but during that process I accidentally ordered 2x Nano BLE 33 not understanding the distinction. Are the microphone chips able to be soldered or added to the BLE 33 to add sound sensing capability? Does anyone know what parts would be needed? I haven't even investigated yet, but will look into the pinout schematics etc. Just wondered if someone knew the answer already. Thank you!

@martin_08, your topic has been moved to a more suitable location on the forum.

Because you ask the question, you likely do not have the necessary skills and equipment to do this. This is a dense PCB with small components. There is a good chance you will damage something in the process.

The part is called MP34DT05. The manufacturer is ST. You can find the datasheet in the store under TECH SPECS.

https://store.arduino.cc/arduino-nano-33-ble-sense

A safer option is to add an external microphone module.