M5Atom using Microphone

M5AtomMic.ino

/**
 * @file M5AtomMic.ino
 * @author botamochi6277 
 * @brief Analog Microphone Test fot M5Atom Series
 * @version 0.1
 * @date 2021-05-07
 * 
 * 
 * @licence MIT LICENCE
 * 
 */
#include "M5Atom.h"

int const ANALOG_PIN = 33;

// buffer for moving avarage filter
int const NUM_BUFFER = 5;
int buffer[NUM_BUFFER];

void setup()
{
    M5.begin(true, false, true);
    pinMode(ANALOG_PIN, INPUT);
    M5.IMU.Init();
}

void loop()
{
    M5.update();
    int value = analogRead(ANALOG_PIN); // 0--4096
    int v = abs(value - 2048);
    v = map(v, 0, 2048, 0, 255);

    pushBack(buffer, v); // update buffer values
    int magnitude = average(buffer);
    // CHSV (uint8_t ih, uint8_t is, uint8_t iv)
    CHSV color = CHSV(127, 255, magnitude);
    M5.dis.clear();
    if (magnitude > 32)
    {
        M5.dis.drawpix(0, color);
    }
    Serial.print(value);
    Serial.print(",");
    Serial.println(magnitude);
    delay(50);
}

int average(int *values)
{
    int sum = 0;
    for (int i = 0; i < NUM_BUFFER; i++)
    {
        sum += values[i];
    }
    return sum / NUM_BUFFER;
}

int pushBack(int *values, int new_value)
{
    for (int i = NUM_BUFFER - 1; i > 0; i--)
    {
        values[i] = values[i - 1];
    }
    values[0] = new_value;
}