Play Grove Analog Microphone With Wio Terminal

Introduction: Play Grove Analog Microphone With Wio Terminal

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The Grove-Analog Microphone is based on high-performance SiSonic MEMS technology, offering an extremely-low-noise, low-current, reliable, and small microphone to opensource hardware industry, and it has improved performance under severe conditions. Grove-Analog Microphone is an ideal choice of sound sensors where excellent audio performance is required. It can provide up to 20dB of gain and it also features low current, max RF protection, which makes it a perfect microphone for Arduino and Raspberry Pi.

This instructable is going to introduce how this Grove-Analog Microphone works via Serial Port commonly, and meanwhile we will display its excellent function on our new-born Wio Terminal, one of the most popular newly-published products of our Seeed Studio! Can't wait? Let's START!!!

Step 1: Play With Arduino

If this is the first time you work with Arduino, we firmly recommend you to see Getting Started with Arduino before the start.

Materials required:


  1. Connect Grove-Sound Sensor to port A0 of Grove-Base Shield. And Plug Grove-Base Shield into Seeeduino and connect Seeeduino to PC via a USB cable.
  2. Please copy below code to Arduino IDE and upload. If you do not know how to upload the code, please check how to upload code.
  Analog input, analog output, serial output

  Reads an analog input pin, maps the result to a range from 0 to 255 and uses
  the result to set the pulse width modulation (PWM) of an output pin.
  Also prints the results to the Serial Monitor.

// These constants won't change. They're used to give names to the pins used:
const int analogInPin = A0;  // Analog input pin that the potentiometer is attached to
const int analogOutPin = 9; // Analog output pin that the LED is attached to

int sensorValue = 0;        // value read from the pot
int outputValue = 0;        // value output to the PWM (analog out)

void setup() {             
  Serial.begin(9600);      // initialize serial communications at 9600 bps

void loop() {
  sensorValue = analogRead(analogInPin);        // read the analog in value
  outputValue = map(sensorValue, 0, 1023, 0, 255);       // map it to the range of the analog out
  analogWrite(analogOutPin, outputValue);               // change the analog out value

  Serial.println(outputValue);    // print the results to the Serial Monitor

  // wait 2 milliseconds before the next loop for the analog-to-digital
  // converter to settle after the last reading:


Click on Serial > Plotter to get the changing curve of the sensor. Please make a noise to view the change of the value.

Step 2: Play With Wio Terminal

Materials required:


  1. Plug Grove-Analog Microphone to Wio Terminal via Grove cable and also connect Wio Terminal to PC through a USB cable.
  2. Copy the demo code into your Arduino IDE and upload.
#include "seeed_line_chart.h" //include the library

TFT_eSPI tft;
#define LINE_DIS 0X00
#define STRING_DIS 0X01
#define max_size 30 //maximum size of data
doubles data;       //Initilising a doubles type to store data
int brightness;
TFT_eSprite spr = TFT_eSprite(&tft); // Sprite

const int MIC = A0; //the microphone amplifier output is connected to pin A0
int adc;
int dB, PdB; //the variable that will hold the value read from the microphone each time
uint8_t mode = LINE_DIS;
void setup()
    Serial.begin(9600); //sets the baud rate at 9600 so we can check the values the microphone is obtaining on the Serial Monitor
    pinMode(A0, INPUT);
    pinMode(WIO_BUZZER, OUTPUT);
    spr.createSprite(TFT_HEIGHT, TFT_WIDTH);

void loop() {
    if (digitalRead(WIO_KEY_C) == LOW) {
        mode ++;
        if(mode > STRING_DIS ) mode = LINE_DIS;

void display(uint8_t mode)
    adc = analogRead(MIC); //Read the ADC value from amplifer
    //Serial.println (adc);//Print ADC for initial calculation
    dB = (adc + 83.2073) / 7.003; //Convert ADC value to dB using Regression values

    if(dB > 50)
        analogWrite(WIO_BUZZER, 128);

        analogWrite(WIO_BUZZER, 0);


    if (data.size() == max_size)
        data.pop(); //this is used to remove the first read variable
    data.push(dB); //read variables and store in data

    //Settings for the line graph title
    auto header = text(0, 0)
                      .value("MIC DB Readings")

    header.height(header.font_height() * 2);
    header.draw(); //Header height is the twice the height of the font
    if (LINE_DIS == mode){
    //Settings for the line graph
    auto content = line_chart(20, header.height()); //(x,y) where the line graph begins
        .height(tft.height() - header.height() * 1.5) //actual height of the line chart
        .width(tft.width() - content.x() * 2)         //actual width of the line chart
        .based_on(0.0)                                //Starting point of y-axis, must be a float
        .show_circle(false)                           //drawing a cirle at each point, default is on.
        .value(data)                                  //passing through the data to line graph
        .color(TFT_RED)                               //Setting the color for the line
    } else if (STRING_DIS == mode){
        for(int8_t line_index = 0;line_index < 5 ; line_index++)
            spr.drawLine(0, 50 + line_index, tft.width(), 50 + line_index, TFT_GREEN);
        auto header =  text(0, 0)
        if(dB > 50){
        spr.drawString(" dB",80 + 100,110,1);
    spr.pushSprite(0, 0);


The image will display on the screen of Wio Terminal if everything goes well.

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    3 months ago on Step 2

    Hi, great project, but I was wondering if you could answer a couple questions for me. How did you determine the equation to convert the analog value to dB? Did you first have to calibrate the microphone? Are these values the same for every sensor module? Why is the conversion from analog value to dB linear if dB are on a logarithmic scale?

    dB = (adc + 83.2073) / 7.003; //Convert ADC value to dB using Regression values