KD2129 Kidsbits STEM Electronic Brick ICS Microphone Module

1. Introduction

This module mainly adopts an ICS-43432 digital microphone chip, which is a high-performance and low-noise MEMS microphone with a bottom microphone hole. It is equipped with an internal MEMS sensor, Σ-Δ ADC, anti-aliasing filter, power manager and interfaces conforming to the I2S standard, and it can directly output 24-bit digital audio signals. Besides, two positioning holes are reserved on it with a diameter of 4.8mm, which is convenient for fixing it on other devices.

2. Parameters

Operating voltage : 3.3V - 5V DC
Interface : I2S digital interface
Signal-to-noise ratio : 65 dBA
Sensitivity : -26 dBFS
Power consumption : 1.5mA
Directivity : Omnidirectional
Data format : 24-bit I2S
Sensitivity tolerance : ±1 dB
Acoustic overload point : 116 dB SPL
Frequency response : 50 HZ - 20 kHZ
Operating temperature : -40°C to +85°C
Dimensions : 48mm × 24mm

3. Working Principle

Chip features:

High-precision 24-bit digital I2S interface
A sensitivity tolerance of -± 1 dB, suitable for microphone array applications
Broadband response, covering both voice and audio ranges
Low-power consumption, suitable for portable devices

I2S interface timing:

The I2S bus consists of three main signals:

SCK: bit clock
WS: word selection
DIN: serial audio data

Function diagram:

Schematic diagram：

4. Pin Description

GND: power ground
VCC: power positive
SCK: bit clock input
DIN: data output
WS: Left and right channel clocks

5. Wiring

Here we take kidsIOT development board as an example:

Component	Quantity
kidsIOT	1
ICS-43432 microphone module	1
Left button 6P6C registered jack 6-core flat PET soft wire	1
TypeC cable	1

Microphone module	kidsIOT
VCC	3.3V
GND	GND
SCK	GPIO14
WS	GPIO12
DIN	GPIO13

6. Environment and Code

Environment Construction

For details, please refer to KidsIOT STEM Education Development Board.

Test Code

Arduino IDE code(based on ESP32):

#include "driver/i2s.h"
#include <Arduino.h>

long avgVol = 0;  

void setup() {
  Serial.begin(115200);
  
  // I2S configuration
  i2s_config_t config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
    .sample_rate = 44100,
    .bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
    .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
    .communication_format = I2S_COMM_FORMAT_STAND_I2S,
    .intr_alloc_flags = 0,
    .dma_buf_count = 4,
    .dma_buf_len = 64,
    .use_apll = false
  };

  i2s_pin_config_t pins = {
    .bck_io_num = 14,
    .ws_io_num = 12,
    .data_out_num = I2S_PIN_NO_CHANGE,
    .data_in_num = 13
  };

  i2s_driver_install(I2S_NUM_0, &config, 0, NULL);
  i2s_set_pin(I2S_NUM_0, &pins);
  i2s_start(I2S_NUM_0);
}

void loop() {
  int32_t samples[64];
  size_t bytes_read;
  
  i2s_read(I2S_NUM_0, samples, sizeof(samples), &bytes_read, portMAX_DELAY);
  
  long total = 0;
  for(int i = 0; i < 64; i++) {
    total += abs(samples[i]);
  }
  
  int raw = total / 64;  
  int scaled = raw / 30000;  
  avgVol = (avgVol * 9 + scaled) / 10;  
  int vol = constrain(avgVol, 0, 1000);  
  Serial.println(vol);  
   
  delay(200); 
}

7. Test Result

After burning the test code, wire up and power on, and turn on the serial monitor.

Normally receive external sounds:

Blow on the module:

Make some noise: