#include <Wire.h>                 // I2C Library
#include <Adafruit_GFX.h>         // OLED Library
#include <Adafruit_SSD1306.h>     // OLED Library
#include "SSD1306Ascii.h"
#include "SSD1306AsciiWire.h"
#include <DallasTemperature.h>    // Temperature sensor Library
#include <Adafruit_MPU6050.h>
#include <LiquidCrystal_I2C.h>

// LCD Display Settings
#define LCD_ADDR 0x27        // LCD I2C address
#define LCD_COLUMNS 20       // Number of columns
#define LCD_ROWS 4           // Number of rows
LiquidCrystal_I2C lcd(LCD_ADDR, LCD_COLUMNS, LCD_ROWS); // Declaring the display name (lcd)

// OLED Display Settings
#define SCREEN_WIDTH 128     // OLED display width, in pixels
#define SCREEN_HEIGHT 64     // OLED display height, in pixels
#define OLED_RESET -1        // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(OLED_RESET); // Declaring the display name (display)

// Accelerometer Setting
Adafruit_MPU6050 mpu;
sensors_event_t accelerometer, gyroscope, temp;
const float STEP_THRESHOLD = 1.5; // Adjust this value to fine-tune step detection
float accMag, gyroMag;
int stepCount = 0;

// Temperature Sensor Setting
#define ONE_WIRE_BUS 3          // Define input pin
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature temperatureSensors(&oneWire);

// Pulse Generator Setting
#define PULSE_PER_BEAT 1
#define PULSE_PIN 2
#define SAMPLING_INTERVAL 1000
volatile uint16_t pulse;
uint16_t count;
float heartRate;

// Interrupt function for pulse generator
void HeartRateInterrupt() {
  pulse++;
}

void setup() {
  // Setup serial monitor
  Serial.begin(115200);
  Serial.println("Started Temperature sensor...");
  lcd.init();
  lcd.backlight();

  // Setup OLED display
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  delay(2000); 
  display.clearDisplay();

  // Setup Temperature sensor
  temperatureSensors.begin();

  // Setup Accelerometer
  while (!mpu.begin()) {
    Serial.println("Accelerometer not working.");
    delay(1000);
  }
  Serial.println("Accelerometer is ready.");

  // Setup pulse generator
  pinMode(PULSE_PIN, INPUT);
  attachInterrupt(digitalPinToInterrupt(PULSE_PIN), HeartRateInterrupt, RISING);
  Serial.println("Started Pulse sensor...");
}

void loop() {
  // Codes for timing
  static unsigned long startTime;
  if (millis() - startTime < SAMPLING_INTERVAL) {
    return;
  }
  startTime = millis();

  // Get temperature readings
  temperatureSensors.requestTemperatures();
  float temperature = temperatureSensors.getTempCByIndex(0);


  // Output temperature to LCD Display
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C");

  // Output temperature to Serial monitor
  Serial.print("Body Temperature: ");
  Serial.print(temperature);
  Serial.println(" C");

  // Calculate and output heart rate
  count = pulse;
  pulse = 0;
  heartRate = map(count, 0, 220, 0, 220);

  lcd.setCursor(0, 1);
  lcd.print("HR: ");
  lcd.print(String(heartRate, 2) + " BPM");
  Serial.println("Heart Rate: " + String(heartRate, 2) + " BPM");

  display.setCursor(0, 10);
  display.print("HR: ");
  display.print(String(heartRate, 2) + " BPM");


}