【Follow me第二季第4期】任务三：学习PDM麦克风技术知识，调试PDM麦克风，通过串...
<p>好了，很快来到了第三个任务，麦克风识别</p><p> </p>
<p>板子上的MP34DT06JTR麦克风还是蛮好好玩的Arduino的代码如下。</p>
<pre>
<code class="language-cpp">#include <WiFiNINA.h>
#include <PDM.h>
bool LED_SWITCH = false;
// default number of output channels
static const char channels = 1;
// default PCM output frequency
static const int frequency = 20000;
// Buffer to read samples into, each sample is 16-bits
short sampleBuffer;
// Number of audio samples read
volatile int samplesRead;
void setup() {
Serial.begin(9600);
pinMode(LEDB, OUTPUT);
while (!Serial);
// Configure the data receive callback
PDM.onReceive(onPDMdata);
// Optionally set the gain
// Defaults to 20 on the BLE Sense and -10 on the Portenta Vision Shields
// PDM.setGain(30);
// Initialize PDM with:
// - one channel (mono mode)
// - a 16 kHz sample rate for the Arduino Nano 33 BLE Sense
// - a 32 kHz or 64 kHz sample rate for the Arduino Portenta Vision Shields
if (!PDM.begin(channels, frequency)) {
Serial.println("启动PDM失败!");
while (1);
}
}
void loop() {
// Wait for samples to be read
if (samplesRead) {
// Print samples to the serial monitor or plotter
for (int i = 0; i < samplesRead; i++) {
if (channels == 2) {
Serial.print("左:");
Serial.print(sampleBuffer);
Serial.print(" 右:");
i++;
}
Serial.println(sampleBuffer);
if (sampleBuffer > 10000 || sampleBuffer <= -10000) {
LED_SWITCH = !LED_SWITCH;
if (LED_SWITCH) {
Serial.println();
digitalWrite(LEDB, HIGH);
Serial.println("开启!");
Serial.println();
delay(1000);
}
else {
Serial.println();
digitalWrite(LEDB, LOW);
Serial.println("关闭!");
Serial.println();
delay(1000);
}
}
}
// Clear the read count
samplesRead = 0;
}
}
/**
Callback function to process the data from the PDM microphone.
NOTE: This callback is executed as part of an ISR.
Therefore using `Serial` to print messages inside this function isn't supported.
* */
void onPDMdata() {
// Query the number of available bytes
int bytesAvailable = PDM.available();
// Read into the sample buffer
PDM.read(sampleBuffer, bytesAvailable);
// 16-bit, 2 bytes per sample
samplesRead = bytesAvailable / 2;
}</code></pre>
<p> </p>
<p>编译完成后就可以在串口监视器和图形窗口看到如下显示了：</p>
<div style="text-align: center;"></div>
<p> </p>
<p>串口曲线显示的是麦克风接收到的声音大小吗？</p>
<p>串口曲线怎么让它显示的数据更多？好像只能显示50连续的50个数</p>
秦天qintian0303 发表于 2024-11-27 08:29
串口曲线怎么让它显示的数据更多？好像只能显示50连续的50个数
<p>这个好像是Arduino为了避免内存占用设计的。绘图仪只是看图，实际数据还是串口输出的更多。</p>
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