#include <LiquidCrystal_I2C.h>
#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>
#include <Wire.h>

#define emer_pin 2
#define count_pin 4
#define buzzer_pin 7

LiquidCrystal_I2C lcd(0x27, 16, 2);
Adafruit_MPU6050 mpu;
sensors_event_t event;

volatile byte state = LOW;
unsigned int counts = 0;
int last_x, last_z;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(emer_pin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(emer_pin), alert, FALLING);
  pinMode(count_pin, INPUT_PULLUP);
  pinMode(buzzer_pin, OUTPUT);
  digitalWrite(buzzer_pin, LOW);

  while (!mpu.begin()) {
    Serial.println("MPU6050 not connected!");
    delay(1000);
  }
  Serial.println("MPU6050 ready!");

  lcd.init();
  lcd.backlight();       // เปิด backlight
  lcd.setCursor(0, 0);
  lcd.print("  CHONVC.AC.TH  ");
  lcd.setCursor(0, 1);
  lcd.print("Ready to start !");
  delay(3000);
}

void loop() {
  // put your main code here, to run repeatedly:
  //Serial.println(digitalRead(emer_pin));
  if(digitalRead(count_pin) == LOW){
    lcd.setCursor(0, 0);
    lcd.print("   Walking...   ");
    lcd.setCursor(0, 1);
    lcd.print("Steps count     ");
    lcd.setCursor(12, 1);
    lcd.print(counts);

    mpu.getAccelerometerSensor()->getEvent(&event);
    last_x = event.acceleration.x;
    last_z = event.acceleration.z;
    mpu.getAccelerometerSensor()->getEvent(&event);
    if((last_x - event.acceleration.x >= 3) && (last_z - event.acceleration.z >= 1)){
      counts++;
      Serial.println("1 Step");
    }
  }
  else{
    lcd.setCursor(0, 0);
    lcd.print("Start button is ");
    lcd.setCursor(0, 1);
    lcd.print("steps count.    ");
  }
  delay(1000);
}

void alert() {
  state = !state;
  Serial.println("Emergency button is press");
  if(state == HIGH){
    digitalWrite(buzzer_pin, HIGH);
  }
  else digitalWrite(buzzer_pin, LOW);
}