【Follow me第二季第4期】-任务3：学习PDM麦克风技术知识，调试PDM麦克风，通过串...

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【Follow me第二季第4期】-任务3：学习PDM麦克风技术知识，调试PDM麦克风，通过串... [复制链接]

 

本次任务为学习PDM麦克风，并打印麦克风采集到的数据。

1、麦克风不需要安装单独的库，在板载资源里有“PDM.h”；

2、初始化串口，启动PDM，选择通道及设置采样频率；如果启动失败，则打印启动PDM失败；

static const char channels = 1;
static const int frequncy  = 24000;
short sampleBuffer[512];
volatile int samplesRead;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  PDM.onReceive(onPDMdata);
  if(!PDM.begin(channels,frequncy))
  {
    Serial.println("Failed to start PDM!!!");
    while(1);


  }

}

3、循环执行声音采样，并打印采样值；

void loop() {
  // put your main code here, to run repeatedly:

  if(samplesRead)
  {
    for(int i = 0; i < samplesRead; i++)
    {
      Serial.println(sampleBuffer[i]);
    }
    samplesRead=0;

  }
  delay(1);

}

4、用串口查看数据；可选择数据才看，也可选择波形查看；波形查看更直观。

 

 

总体代码如下：

#include "PDM.h"

static const char channels = 1;
static const int frequncy  = 24000;
short sampleBuffer[512];
volatile int samplesRead;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  PDM.onReceive(onPDMdata);
  if(!PDM.begin(channels,frequncy))
  {
    Serial.println("Failed to start PDM!!!");
    while(1);


  }

}

void loop() {
  // put your main code here, to run repeatedly:

  if(samplesRead)
  {
    for(int i = 0; i < samplesRead; i++)
    {
      Serial.println(sampleBuffer[i]);
    }
    samplesRead=0;

  }
  delay(1);

}

void onPDMdata(){
  int bytesAvailable = PDM.available();
  PDM.read(sampleBuffer,bytesAvailable);
  samplesRead = bytesAvailable / 2;

}