sensor-mic.js

import five from 'johnny-five';

const board = new five.Board();
const SAMPLE_SIZE = 50;
const SAMPLE_FREQ = 1;
const SAMPLE_TIMES = 10;

board.on("ready", function() {
  const mic = new five.Sensor({ 
      pin:"A0",
      freq: SAMPLE_FREQ 
  });

  let data = [];
  let range = [];

  mic.on("data", function() {
    if (data.length === SAMPLE_SIZE) {
        const min = data.reduce((min, current) => min>current ? current : min, 100000);  
        const max = data.reduce((max, current) => max<current ? current : max, 0);
        const voltage = (max-min)*3.3/1024.0;
        range.push(voltage);
        data = [];
    }
    if (range.length === SAMPLE_TIMES) {
        const total = range.reduce((total, current) => total+current, 0);
        console.log(total/range.length);
        range = [];
    }
    data.push(this.value);
  });
});