Arduino--音乐频谱

news2025/1/21 15:43:50

本文主要介绍基于Arduino实现的音乐频谱显示，音乐频谱原理就是声音传感器（MIC）接收音频信号后通过FFT将时域信号转换成频域信号，再将音频信号频域分量分别显示在对应的LED点阵屏上，呈现出音乐随频律动的感觉，整体效果比较赏心悦目
完整代码见文末链接（含相关头文件）

（1）简介

首先介绍实现本文所需要的主要器件：
（1）Arduino开发板：全系列均可以，本文主要以UNO为例
（2）MAX7219 LED点阵模块
有关于该模块的详细介绍见：https://blog.csdn.net/u011816009/article/details/124309755
（3）声音传感器：要求能模拟量输出，理论上只要能输出模拟量的都可以，我是电子大楼随意几块钱买了个，也能正常使用
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（2）接线图

接线图相对比较简单，按照下图示意接线即可
在这里插入图片描述

（3）程序代码

初始化配置

include "LedControl.h"

/* Led matrix - Max7219 Declared */
LedControl lc = LedControl(7, 6, 5, 1);

const int maxScale = 50;

/* Sensor - Max9812 Declared */
const int sensorPin = A4;
const int sampleWindow = 50; // 50ms = 20Hz
unsigned int sample;

主函数如下

void loop() {
startMillis = millis();
//peakToPeak = 0;

signalMax = 0;
signalMin = 255;

// Get data in 50ms
while (millis() - startMillis < sampleWindow) {
sample = analogRead(sensorPin);

if (sample < 255) {
if (sample > signalMax) {
signalMax = sample;
}
if (sample < signalMin) {
signalMin = sample;
}
}

// 20Hz - 64Hz - 125Hz - 250Hz - 500Hz - 1kHz (timeCycle = 1/F)(ms)
timeCycle = millis() - startMillis;
if (timeCycle == 1 || timeCycle == 2 || timeCycle == 4 || timeCycle == 8
|| timeCycle == 16 || timeCycle == 32 || timeCycle == 40 || timeCycle == 50) {
signalMaxBuff[index] = signalMax;
signalMinBuff[index] = signalMin;
index = (index + 1) % 8;
delay(1);
//Serial.println(timeCycle);
}
}

// Delete pointer to array
index = 0;

// Calculation after get samples
for (int i = 0; i < 8; i++) { // i = row (led matrix)
// sound level
peakToPeak[i] = signalMaxBuff[i] - signalMinBuff[i];

// Map 1v p-p level to the max scale of the display
displayPeak[i] = map(peakToPeak[i], 0, 254, 0, maxScale);

// Show to led matrix
displayLed(displayPeak[i], i);

// Led drop down
if (displayPeak[i] >= temp[i]) {
temp[i] = displayPeak[i];
}
else {
temp[i]--;
}