ESP32藍芽音樂分頻播放器

esp32藍芽音樂

https://github.com/tierneytim/btAudio  下載涵式庫安裝，執行範例裡的minimalAudio 

TFT_LCD驅動

使用ARDUION管理程式庫下載TFT_eSPI安裝，安裝之後需依你使用的TFT進行設定Documents\Arduino\libraries\TFT_eSPI目錄裡的User_Setup.h，以我這次使用的ST7789為例：

可以參考這篇：github.com/Makerfabs/Makerfabs-MakePython-ESP32-Color-LCD 

整個機構的運作原理是用手機或平板的藍芽連上它，開始播放聲音，聲音感測器接收了聲音分成了七個音頻段利用TFT動態地顯示，以這個範例來說：程式不停地偵測PIN34接收的聲音並依接收值區分成七個頻率段，再利用displayBand這個涵式將這個值轉換成TFT螢幕上的動態方塊

void loop()

{

    for (int i = 0; i < SAMPLES; i++) {

        newTime = micros()-oldTime;

        oldTime = newTime;

        vReal[i] = analogRead(34); // A conversion takes about 1uS on an ESP32

        vImag[i] = 0;

        while (micros() < (newTime + sampling_period_us)) { /* do nothing to wait */ }

        }

    FFT.Windowing(vReal, SAMPLES, FFT_WIN_TYP_HAMMING, FFT_FORWARD);

    FFT.Compute(vReal, vImag, SAMPLES, FFT_FORWARD);

    FFT.ComplexToMagnitude(vReal, vImag, SAMPLES);

    tft.fillScreen(color[6]);

    tft.setCursor(0, 210);

    tft.setTextColor(0xf81f);

    tft.setTextSize(2);

    tft.println("01 02 05 1k 2k 4k 8k ");

    for (int i = 2; i < (SAMPLES/2); i++){

    if (vReal[i] > 1500) { 

      if (i<=2 )             displayBand(0,(int)vReal[i]); // 125Hz

      if (i >2   && i<=4 )   displayBand(1,(int)vReal[i]); // 250Hz

      if (i >4   && i<=7 )   displayBand(2,(int)vReal[i]); // 500Hz

      if (i >7   && i<=15 )  displayBand(3,(int)vReal[i]); // 1000Hz

      if (i >15  && i<=40 )  displayBand(4,(int)vReal[i]); // 2000Hz

      if (i >40  && i<=70 )  displayBand(5,(int)vReal[i]); // 4000Hz

      if (i >70  && i<=288 ) displayBand(6,(int)vReal[i]); // 8000Hz

      if (i >288           ) displayBand(7,(int)vReal[i]); // 16000Hz

    }

    for (byte band = 0; band <= 7; band++) tft.drawLine(36*band,200-peak[band],36*band+28,200-peak[band],color[4]);

  }

  if (millis()%2 == 0) {for (byte band = 0; band <= 7; band++) {if (peak[band] > 4) peak[band] -= 4;if (peak[band] < 4) peak[band] = 0;}} // Decay the peak

}

void displayBand(int band, int dsize){

  int dmax = 200;

  dsize /= amplitude;

  if (dsize > dmax) dsize = dmax;

  if (band == 7) tft.drawLine(36*6,200, 36*6+28,200,color[7]);

  for (int s = 0; s <= dsize; s=s+8) {

    if (s <30 ) tft.fillRect(band*36,200-s, 28, 5,  color[7]);

    if (s >=30 ) tft.fillRect(band*36,200-s, 28, 5,  color[4]);

  }

  if (dsize > peak[band]) {peak[band] = dsize;}

}