DIY Arduino VFO with AD9850 & TM1638 Pure Sine Wave Signal

// by mircemk Mar.2026

#include <TM1638lite.h>

TM1638lite module(4, 3, 2); 

#define W_CLK 8
#define FQ_UD 9
#define DATA 10
#define RESET 11
#define ENC_A A0
#define ENC_B A1
#define ENC_SW A2 // Копчето на енкодерот

unsigned long freq = 7000000; 
unsigned long steps[] = {10, 100, 1000, 10000, 100000, 1000000};
int stepIndex = 2; 
const char* modes[] = {"A       ", "USB     ", "LSB     "};
int modeIndex = 0;
long offset = 0; 
bool offsetActive = false;

// Brightness контроли
int brightnessPercent = 50; // Почетна на 50%
bool brightnessMode = false;

unsigned long tempDisplayTimer = 0;
bool showingTemp = false;

const byte segmentMap[] = { 0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F };

void setup() {
  pinMode(W_CLK, OUTPUT); pinMode(FQ_UD, OUTPUT);
  pinMode(DATA, OUTPUT);  pinMode(RESET, OUTPUT);
  pinMode(ENC_A, INPUT_PULLUP); 
  pinMode(ENC_B, INPUT_PULLUP);
  pinMode(ENC_SW, INPUT_PULLUP);
  
  ad9850_reset();
  updateDDS(freq + offset);
  setBrightnessLevel(brightnessPercent);
  updateMainDisplay();
}

void loop() {
  // Читање на копчето на енкодерот (A3)
  if (digitalRead(ENC_SW) == LOW) {
    brightnessMode = !brightnessMode;
    if (brightnessMode) showTempMsg("BRIGHT  ");
    else updateMainDisplay();
    delay(300); // Debounce
  }

  uint8_t buttons = module.readButtons();

  // Додека сме во Brightness Mode, другите тастери се деактивирани
  if (!brightnessMode) {
    if (buttons == 1) { 
      stepIndex = (stepIndex + 1) % 6;
      char buffer[9];
      sprintf(buffer, "S%7ld", steps[stepIndex]); 
      showTempMsg(buffer);
      while(module.readButtons() == 1); 
    }
    if (buttons == 2) {
      modeIndex = (modeIndex + 1) % 3;
      showTempMsg(modes[modeIndex]);
      while(module.readButtons() == 2);
    }
    if (buttons == 4)   setBand(1800000, 2); 
    if (buttons == 8)   setBand(3500000, 3); 
    if (buttons == 16)  setBand(7000000, 4); 
    if (buttons == 32)  setBand(14000000, 5); 
    if (buttons == 64)  setBand(21000000, 6); 

    if (buttons == 128) {
      offsetActive = !offsetActive;
      offset = offsetActive ? 455000 : 0;
      showTempMsg(offsetActive ? "_455_   " : "OFF     ");
      module.setLED(7, offsetActive ? 1 : 0); 
      updateDDS(freq + offset);
      while(module.readButtons() == 128);
    }
  }

  // Енкодер логика (за Фреквенција или за Brightness)
  static int lastA = HIGH;
  int currentA = digitalRead(ENC_A);
  if (currentA != lastA && currentA == LOW) {
    if (brightnessMode) {
      // Менување на осветленост (чекор по 10%)
      if (digitalRead(ENC_B) == LOW) brightnessPercent -= 10;
      else brightnessPercent += 10;
      brightnessPercent = constrain(brightnessPercent, 0, 100);
      
      setBrightnessLevel(brightnessPercent);
      char brBuf[9];
      sprintf(brBuf, "BR  %3d ", brightnessPercent);
      module.displayText(brBuf);
    } else {
      // Стандардна фреквенција
      if (digitalRead(ENC_B) == LOW) freq -= steps[stepIndex];
      else freq += steps[stepIndex];
      freq = constrain(freq, 0, 49999999);
      updateDDS(freq + offset);
      if (!showingTemp) updateMainDisplay();
    }
  }
  lastA = currentA;

  if (showingTemp && (millis() > tempDisplayTimer) && !brightnessMode) {
    showingTemp = false;
    updateMainDisplay();
  }
}

void showTempMsg(const char* msg) {
  module.displayText(msg);
  tempDisplayTimer = millis() + 1000;
  showingTemp = true;
}

void setBrightnessLevel(int percent) {
  // TM1638 користи 0x88 (минимум) до 0x8F (максимум) за осветленост
  byte level = map(percent, 0, 100, 0, 7);
  digitalWrite(4, LOW); // STB
  shiftOut(2, 3, LSBFIRST, 0x88 + level); 
  digitalWrite(4, HIGH); // STB
}

void updateMainDisplay() {
  unsigned long tempFreq = freq;
  for (int i = 7; i >= 0; i--) {
    byte segs = 0;
    if (tempFreq > 0 || i == 7) { 
      segs = segmentMap[tempFreq % 10];
      tempFreq /= 10;
    } else {
      segs = 0x00; 
    }
    if (i == 1 || i == 4) segs |= 0x80; 
    sendRawData(i, segs);
  }
}

void sendRawData(byte position, byte data) {
  digitalWrite(4, LOW);
  shiftOut(2, 3, LSBFIRST, 0xC0 + (position * 2));
  shiftOut(2, 3, LSBFIRST, data);
  digitalWrite(4, HIGH);
}

void setBand(unsigned long f, int ledIndex) {
  freq = f;
  for (int i = 0; i < 7; i++) module.setLED(i, 0); 
  module.setLED(ledIndex, 1); 
  updateDDS(freq + offset);
  updateMainDisplay();
}

void ad9850_reset() {
  digitalWrite(W_CLK, LOW); digitalWrite(FQ_UD, LOW);
  digitalWrite(RESET, LOW); digitalWrite(RESET, HIGH); digitalWrite(RESET, LOW);
}

void updateDDS(unsigned long f) {
  unsigned long tuning_word = f * 4294967296ULL / 125000000;
  for (int i = 0; i < 32; i++) {
    digitalWrite(DATA, tuning_word & 0x01);
    digitalWrite(W_CLK, HIGH); digitalWrite(W_CLK, LOW);
    tuning_word >>= 1;
  }
  for (int i = 0; i < 8; i++) {
    digitalWrite(DATA, LOW);
    digitalWrite(W_CLK, HIGH); digitalWrite(W_CLK, LOW);
  }
  digitalWrite(FQ_UD, HIGH); digitalWrite(FQ_UD, LOW);
}