#include <driver/ledc.h>
#include <math.h>

// Define PWM properties
const int pwmFreq = 390000;  // 390kHz PWM frequency
const int pwmResolution = 7;  // 7-bit resolution

// Define output pins for H-bridge (connected to MOSFET gates)
const int pwmPinA = 16; // PWM for half-bridge A
const int pwmPinB = 17; // PWM for half-bridge B

// Define enable pins for H-bridge
const int enablePin1 = 18; // Enable pin for H-bridge side 1
const int enablePin2 = 19; // Enable pin for H-bridge side 2

// Define sine wave parameters
const int sineResolution = 100;  // Number of points in one sine wave cycle
int sineTable[sineResolution];

// Define pulse timing parameters
const unsigned long pulseDuration = 100;  // 100ms
const unsigned long pulseInterval = 1000;  // 1s
unsigned long lastPulseTime = 0;

// Define deadband parameters
const int deadband = 5; // Deadband duration in microseconds

void setup() {
  // Configure PWM pins as outputs
  pinMode(pwmPinA, OUTPUT);
  pinMode(pwmPinB, OUTPUT);

  // Configure enable pins as outputs
  pinMode(enablePin1, OUTPUT);
  pinMode(enablePin2, OUTPUT);

  // Enable H-bridge initially
  digitalWrite(enablePin1, HIGH);
  digitalWrite(enablePin2, HIGH);

  // Configure and attach PWM pins
  ledcAttach(pwmPinA, pwmFreq, pwmResolution);
  ledcAttach(pwmPinB, pwmFreq, pwmResolution);

  // Generate sine table
  for (int i = 0; i < sineResolution; i++) {
    sineTable[i] = (int)(sin(i * 2.0 * PI / sineResolution) * ((1 << pwmResolution) - 1) / 2);
  }
}

void loop() {
  unsigned long currentTime = millis();

  // Check if it's time to start a new pulse
  if (currentTime - lastPulseTime >= pulseInterval) {
    lastPulseTime = currentTime;
  }

  // Generate a sine pulse if within the pulse duration
  if (currentTime - lastPulseTime < pulseDuration) {
    static unsigned long lastTime = 0;
    static int index = 0;

    // Calculate time for one full sine wave cycle at 40kHz
    unsigned long cycleTime = 1000 / 40;

    // Update index based on elapsed time
    if (micros() - lastTime >= cycleTime * 1000 / sineResolution) {
      lastTime = micros();

      // Set PWM duty cycle based on sine table
      int dutyCycle = sineTable[index];

      // Implement deadband
      digitalWrite(enablePin1, LOW);
      digitalWrite(enablePin2, LOW);
      delayMicroseconds(deadband);

      // Bipolar modulation: activate MOSFETs alternately
      if (dutyCycle >= 0) {
        ledcWrite(pwmPinA, dutyCycle);
        ledcWrite(pwmPinB, 0);
      } else {
        ledcWrite(pwmPinA, 0);
        ledcWrite(pwmPinB, -dutyCycle);
      }

      // Enable H-bridge after deadband
      digitalWrite(enablePin1, HIGH);
      digitalWrite(enablePin2, HIGH);

      // Update index and reset if it reaches sine resolution
      index++;
      if (index >= sineResolution) {
        index = 0;
      }
    }
  } else {
    // Disable PWM output outside the pulse duration
    ledcWrite(pwmPinA, 0);
    ledcWrite(pwmPinB, 0);
  }
}