Exemplu de schemă bloc: http://www.robs-projects.com/mp3proj/newplayer.html

• listă de piese
• scheme electrice (se pot lua şi de pe Internet şi din datasheet-uri, e.g. http://www.captain.at/electronic-atmega16-mmc-schematic.png)
• diagrame de semnal
• rezultatele simulării

const int maxScale = 11; const int sensorPin = A4; const int sampleWindow = 50; 50ms = 20Hz unsigned int sample; unsigned long startMillis; unsigned long timeCycle; unsigned int signalMax = 0; unsigned int signalMin = 1024; unsigned char index = 0; unsigned int peakToPeak[8]; unsigned int displayPeak[8]; unsigned int temp[8]={0,0,0,0,0,0,0,0}; unsigned int signalMaxBuff[8]; unsigned int signalMinBuff[8]; void setup() { Led matrix

lc.shutdown(0, false); // bật hiện thị
lc.setIntensity(0, 1); // chỉnh độ sáng 
lc.clearDisplay(0); // tắt tất cả led

Serial.begin(9600);

}

void loop() {

startMillis = millis();
//peakToPeak = 0;

signalMax = 0;
signalMin = 1024;

// Get data in 50ms
while (millis() - startMillis < sampleWindow) {
  sample = analogRead(sensorPin);
  
  if (sample < 1024) {
    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, 1023, 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]--;
  }
  
  lc.setLed(0, i, temp[i], true);
  delayMicroseconds(250);
}
 

}

void displayLed(int displayPeak, int row) {

switch (displayPeak) {
  case 0 : lc.setRow(0, row, 0x80); break;
  case 1 : lc.setRow(0, row, 0xC0); break;
  case 2 : lc.setRow(0, row, 0xE0); break;
  case 3 : lc.setRow(0, row, 0xF0); break;
  case 4 : lc.setRow(0, row, 0xF8); break;
  case 5 : lc.setRow(0, row, 0xFC); break;
  case 6 : lc.setRow(0, row, 0xFE); break;
  case 7 : lc.setRow(0, row, 0xFF); break;
}

}