#include <Arduino.h>

#define LED 2
#define BUTTON_PIN 32
#define SLIDER_BPM 34
#define SLIDER_AMPLITUDE 35

hw_timer_t *My_timer = NULL;
volatile bool arythmiaMode = false;
volatile float adValue = -10;
volatile float bpm = 60; // Default BPM
volatile float amplitude = 1.0; // Full amplitude

void IRAM_ATTR onTimer() {
  static int vector = 0;
  if (!arythmiaMode) {
    // Normal sinus rhythm
    adValue = 120 + 120 * sin(vector * PI / 180) * amplitude; // Centered around 120, amplitude of 120
  } else {
    // Ventricular fibrillation simulation
    adValue = 120 + 120 * (random(-100, 100) / 100.0) * amplitude; // Random fluctuations centered around 120
  }

  if (++vector >= 360) vector = 0;
}

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(SLIDER_BPM, INPUT);
  pinMode(SLIDER_AMPLITUDE, INPUT);
  My_timer = timerBegin(0, 80, true); // Prescaler 80, timer 0
  timerAttachInterrupt(My_timer, &onTimer, true);
  timerAlarmWrite(My_timer, 1000000 / (bpm / 60), true); // Correct timer period calculation
  timerAlarmEnable(My_timer);
  Serial.begin(115200);
}

void loop() {
  if (digitalRead(BUTTON_PIN) == LOW) {
    arythmiaMode = !arythmiaMode;
    delay(500); // Debouncing
  }

  // Read and map BPM from the analog reading
  int newBpmReading = analogRead(SLIDER_BPM);
  bpm = map(newBpmReading, 0, 4095, 40, 240);

  // Read and convert amplitude percentage directly
  int newAmplitudeReading = analogRead(SLIDER_AMPLITUDE);
  amplitude = map(newAmplitudeReading, 0, 4095, 10, 100) / 100.0;

  // Update the timer based on the new BPM
  timerAlarmWrite(My_timer, 1000000 / (bpm / 60), true);

  if (adValue != -10) {
    Serial.print(adValue, 6);
    Serial.println();
    dacWrite(GPIO_NUM_25, map(adValue * 10, -1, 1, 0, 255));
    adValue = -10;
  }
}