Arduino+MAX9814制作简易录音机

MAX9814

这个示例是用MAX9814进行录音，并生成一个wav文件保存到SD上。如果用ESP8266可以不使用SD卡模块直接将文件存到云。

BOM

• MAX9814 模块
• MicroSDCard 模块
• Arduino Uno

线路图

电路图

代码

这里我使用了一个叫TMRpcm的库，这个库在Arduino上非常好用，它本来是做软DAC用的，可以用来扩展Arduino进行直接的声音解码播放。另外TMRpcm里面还有一个用于录音的方法，源码中是被注释掉的，在安装该库之后需要打开源码库中的pcmConfig.h文件将以下的行取消注释，否则会编译不通过：

#define buffSize 128. May need to increase.
#define ENABLE_RECORDING 
#define BLOCK_COUNT 10000UL

以下是 Arduino 代码:

#include 
#include 
#include 

#define SD_ChipSelectPin 10  //using digital pin 4 on arduino nano 328, can use other pins

TMRpcm audio;   // create an object for use in this sketch 
void setup() {
  
  audio.speakerPin = 4; 

  Serial.begin(115200);
  
  if (!SD.begin(SD_ChipSelectPin)) {  
    Serial.println("SD Fail");
    return;
  }else{
    Serial.println("SD OK"); 
  }
  // The audio library needs to know which CS pin to use for recording
  audio.CSPin = SD_ChipSelectPin;
}


void loop() {
  
    if(Serial.available()){                          //Send commands over serial to play
      char c = Serial.read();
      Serial.println(c);
      switch(c){
        case 'r': audio.startRecording("test.wav",16000,A0); break;    //Record at 16khz sample rate on pin A0
        case 'R': audio.startRecording("test.wav",16000,A0,1); break;  //Record, but with passthrough to speaker.
        case 't': audio.startRecording("test.wav",16000,A0,2); break;  //Do not record. Output direct to speaker
                                           //Note: If samples are dropped before writing, it
                                           //      will not be heard in passthrough mode
        case 's': audio.stopRecording("test.wav"); break;              //Stop recording
        case 'p': audio.play("test.wav"); break;                       //Play the recording 
        case '=': audio.volume(1); break;                              //Increase volume by 1. Does not affect recording
        case '-': audio.volume(0); break;                              //Decrease volume by 1. Does not affect recording
        case 'S': audio.stopPlayback(); break;                         //Stop all playback
        
      }
    }
}

参考

• Make your own spy bug Arduino Voice recorder
• TMRpcm库
• MAX9814 - Adafruit 上的产品介绍