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Question

How can PicoW read MEMS digital microphone output?

Answer

Introduction

1. Overview.

We can connect the MEMS microphone output pin to a PicoW GPIO pin and read signal, into a list for later processing.

2. Simulation

For prototyping, we can simulate the microphone output signal as a GPIO output pin connected blinking LED, and use another GPIO input pin to read the blinking LED pin.

3. / to continue, ...

References

(1) Adafruit PDM Microphone Breakout 1

(2) Adafruit PDM Microphone Breakout 2

(3) AliExpress Digital MP34DT01 Microphone Module Simple Pulse Density Modulation Output PDM Digital MEMS Microphone Module - HK$27

(4) TaoBao MP34DT01 MEMS PDM Microphone - ¥25

(5) 1000 Hz Test Tone - Sonic Electronix

Appendices

Appendix A - MicroPython program blinking two LEDs simulating two MEMS digital microphone output signals

# Pico W Blink Two LEDs - tlfong01 2023jan01hkt1941

# *** Modules ***
import machine
from machine import Pin, Timer

# *** Configuration***
redLed      = Pin(0, Pin.OUT)
greenLed    = Pin(1, Pin.OUT)

redFreq     = 2
greenFreq   = 4

redTimer    = Timer()
greenTimer  = Timer()

# *** Callbacks ***
def blinkRedLed(dummy):
    redLed.toggle()
    return

def blinkGreenLed(dummy):
    greenLed.toggle()
    return

# *** Main ***
redTimer.init(freq = redFreq, mode = Timer.PERIODIC, callback = blinkRedLed)
greenTimer.init(freq = greenFreq, mode = Timer.PERIODIC, callback = blinkGreenLed)

# *** End of program ***

Appendix B - Blinking LEDs Video

PicoW blinking two LEDS