VU metru cu Arduino si ST7735

 Va salut !

La cererea prietenului Dragos (care mi-a trimis un clip cu un vu-metru cu display color), bazandu-ma pe IA am conceput acest vu-metru, cu un Arduino Nano si un display LCD tip ST7735. 

Are un encoder care permite selectia diferitelor tipuri de afisare ; rotirea encoderului permite navigarea printre moduri, apasarea permite selectarea/deselectarea modurilor (se pot selecta toate). Prin combinatiile intre moduri se poate ajunge la o functionare conforma preferintelor.

Semnalul audio se aplica pe pinii A0 si A1.

Aici am postat un mic clip cu functionarea.

Enjoy ! 

 

UPDATE 12.07.2026 : Soft modificat ; functioneaza bine cu preamp de microfon condenser cu LM386

#include <Adafruit_GFX.h>    
#include <Adafruit_ST7735.h> 
#include <SPI.h>
#include <Encoder.h>         

#define TFT_CS     10
#define TFT_RST    9
#define TFT_DC     8
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_RST);

Encoder myEnc(2, 3);
#define ENC_SW 4 

const char* menuOptions[] = {"PEAK HLD", "FULL SCR", "WIDE AGC", "SMOOTH"};
const uint16_t menuColors[] = {ST7735_WHITE, ST7735_YELLOW, 0x07E0, 0x07FF}; 

bool optStates[] = {true, false, false, false}; 
int menuIndex = 0;
int lastMenuIndex = -1; 
long oldPosition = -999;
int leftPeak = 0, rightPeak = 0;
int lastLeftPeakY = 139, lastRightPeakY = 139;
unsigned long lastPeakMillis = 0;
unsigned long lastButtonMillis = 0; 

byte lastStateL[15]; 
byte lastStateR[15];
int lastLvlH = -1;

const int BORDER_X = 65;      
const int BORDER_W = 58;      
const int BAR_W = 18;         
const int PADDING = 6;        
const int POS_L = BORDER_X + PADDING;      
const int POS_R = BORDER_X + BORDER_W - PADDING - BAR_W; 

void setup() {
  pinMode(ENC_SW, INPUT_PULLUP);
  tft.initR(INITR_BLACKTAB);
  tft.setRotation(0); 
  tft.fillScreen(ST7735_BLACK);
  
  for(int i = 0; i < 15; i++) {
    lastStateL[i] = 255; 
    lastStateR[i] = 255;
  }
  
  deseneazaInterfataStatica();
  actualizeazaSelector(0);
}

void loop() {
  // 1. ROTATIE ENCODER
  long newPos = myEnc.read() / 4;
  if (newPos != oldPosition) {
    menuIndex = abs(newPos % 4);
    actualizeazaSelector(menuIndex);
    oldPosition = newPos;
  }

  // 2. APASARE BUTON
  if (digitalRead(ENC_SW) == LOW) {
    if (millis() - lastButtonMillis > 300) { 
      optStates[menuIndex] = !optStates[menuIndex];
      tft.fillRect(59, 40 + (menuIndex * 12), 4, 8, ST7735_BLACK);
      if (optStates[menuIndex]) {
        tft.fillRect(59, 43 + (menuIndex * 12), 3, 3, ST7735_GREEN);
      }
      lastButtonMillis = millis();
    }
  }

  // --- 3. ESANTIONARE AUDIO STEREO REALA ---
  int signalMaxL = 0, signalMinL = 1023;
  int signalMaxR = 0, signalMinR = 1023;
  
  unsigned long startMillis = millis();
  while (millis() - startMillis < 30) {
    int sampleL = analogRead(A0);
    int sampleR = analogRead(A1);
    
    if (sampleL < 1024) {
      if (sampleL > signalMaxL) signalMaxL = sampleL;
      if (sampleL < signalMinL) signalMinL = sampleL;
    }
    if (sampleR < 1024) {
      if (sampleR > signalMaxR) signalMaxR = sampleR;
      if (sampleR < signalMinR) signalMinR = sampleR;
    }
  }

  // Calculam amplitudinea Peak-to-Peak (Stereo Independent)
  int peakToPeakL = signalMaxL - signalMinL;
  int peakToPeakR = signalMaxR - signalMinR;


  // Sensibilitatea dinamica din meniu (WIDE AGC)
  int maxVal = optStates[2] ? 40 : 180; 

  int segL = constrain(map(peakToPeakL, 4, maxVal, 0, 15), 0, 15);
  int segR = constrain(map(peakToPeakR, 4, maxVal, 0, 15), 0, 15);
  
  // 4. LOGICA PEAK HOLD
  int curPeakL = map(segL, 0, 15, 0, 92);
  int curPeakR = map(segR, 0, 15, 0, 92);
  
  if (curPeakL > leftPeak) leftPeak = curPeakL;
  if (curPeakR > rightPeak) rightPeak = curPeakR;

  // --- TIMING SI VITEZA ACCELERATA DE REVENIRE LA ZERO ---
  int fallSpeed = optStates[3] ? 90 : 35; // Mai rapid decat inainte (35ms vs 50ms)
  if (millis() - lastPeakMillis > fallSpeed) {
    if (leftPeak > 0) leftPeak -= 3;   // REPARAT: Scade cu 3 pixeli deodata pentru o coborare mult mai alerta
    if (rightPeak > 0) rightPeak -= 3; // REPARAT: Scade cu 3 pixeli deodata pentru o coborare mult mai alerta
    
    if (leftPeak < 0) leftPeak = 0;
    if (rightPeak < 0) rightPeak = 0;
    lastPeakMillis = millis();
  }

  if (!optStates[0]) { leftPeak = 0; rightPeak = 0; }

  // 5. DESENARE STEREO INDEPENDENTA
  actualizeazaBaraBruta(POS_L, segL, leftPeak, lastLeftPeakY, optStates[0], lastStateL); 
  actualizeazaBaraBruta(POS_R, segR, rightPeak, lastRightPeakY, optStates[0], lastStateR);

  // 6. INDICATOR LEVEL
  int lvlH = constrain(map(peakToPeakL, 4, maxVal, 0, 49), 0, 49); 
  if (lvlH != lastLvlH) {
    int yBaseLevel = 140; 
    tft.fillRect(30, yBaseLevel - lvlH, 10, lvlH, 0x5DFF);
    if (lvlH < 49) {
       tft.fillRect(30, 91, 10, 49 - lvlH, 0x000F);
    }
    lastLvlH = lvlH;
  }
}

void actualizeazaBaraBruta(int x, int val, int peak, int &lY, bool peakActive, byte last[]) {
  for (int i = 0; i < 15; i++) {
    byte s = (i < val) ? 1 : 0;
    if (s != last[i]) {
      uint16_t c = (s == 1) ? (i < 9 ? ST7735_GREEN : (i < 12 ? ST7735_YELLOW : ST7735_RED)) : 0x1082;
      tft.fillRect(x, 135 - (i * 6), BAR_W, 4, c);
      last[i] = s;
    }
  }
  int cY = 139 - peak;
  if (cY != lY) {
    tft.drawFastHLine(x, lY, BAR_W, ST7735_BLACK); 
    lY = cY;
  }
  if (peakActive && peak > 2) {
    tft.drawFastHLine(x, cY, BAR_W, ST7735_WHITE); 
  }
}

void deseneazaInterfataStatica() {
  tft.fillRect(5, 5, 118, 20, ST7735_BLUE);
  tft.setTextColor(ST7735_WHITE);
  tft.setCursor(38, 12); tft.print("VU METER");
  for (int i = 0; i < 4; i++) {
    tft.setTextColor(menuColors[i]);
    tft.setCursor(10, 40 + (i * 12)); tft.print(menuOptions[i]);
  }
  tft.drawRect(BORDER_X, 40, BORDER_W, 101, ST7735_WHITE); 
  tft.fillRect(POS_L, 145, BAR_W, 12, ST7735_RED);
  tft.fillRect(POS_R, 145, BAR_W, 12, ST7735_RED);
  tft.setTextColor(ST7735_WHITE); 
  tft.setCursor(POS_L + 6, 147); tft.print("L");
  tft.setCursor(POS_R + 6, 147); tft.print("R");
  int xLvl = 30; int yTop = 90; int yBot = 141;
  tft.drawRect(xLvl - 1, yTop, 12, (yBot - yTop) + 1, ST7735_WHITE); 
  tft.setCursor(12, yTop + 2); tft.print("10");
  tft.setCursor(18, yBot - 8); tft.print("0"); 
  tft.setCursor(20, 147); tft.print("LEVEL");
  for (int i = 0; i <= 10; i++) {
    int yT = yBot - (i * 5);
    tft.drawFastHLine(xLvl - 4, yT, 3, ST7735_WHITE);
    tft.drawFastHLine(xLvl + 11, yT, 3, ST7735_WHITE);
  }
}

void actualizeazaSelector(int index) {
  if (index != lastMenuIndex) {
    if (lastMenuIndex >= 0) tft.fillRect(1, 40 + (lastMenuIndex * 12), 6, 8, ST7735_BLACK);
    tft.setTextColor(ST7735_RED); tft.setCursor(1, 40 + (index * 12)); tft.print(">");
    lastMenuIndex = index;
  }
  for(int i = 0; i < 4; i++) {
    tft.fillRect(59, 40 + (i * 12), 4, 8, ST7735_BLACK); 
    if (optStates[i]) tft.fillRect(59, 43 + (i * 12), 3, 3, ST7735_GREEN);
  }
}