// Bluetooth controlled lights using arudino uno and hc-05 bluetooth module
// This code was originally written for instructables: https://www.instructables.com/member/piyushsuteri/
// Youtube video available at: https://www.youtube.com/@piyushsuteri and https://youtube.com/shorts/8NufHkCCvnI?feature=share
// Author: Piyush Suteri
// 13:14, 16 March 2023
// bluetooth app link: https://play.google.com/store/apps/details?id=com.himanshu.ArduinoAutomation&pli=1
// disconnect tx and rx pins of bluetooth module before uploading this code


#define led_pin 7    // pin to which anode of indication led is connected
#define relay_pin 11  // pin to which signal pin of relay module is connected
char val;             // integer variable which stores data recieved from mobile app via bluetooth

void setup() {                 // put your setup code here, to run once:
  pinMode(led_pin, OUTPUT);    // define led_pin as output
  pinMode(relay_pin, OUTPUT);  // define relay_pin as output
  Serial.begin(9600);          // initalize serial communication
}

void loop() {                // put your main code here, to run repeatedly:
  if (Serial.available()) {  // check if data is recieved from bluetooth module
    val = Serial.read();     // store data recieved from bluetooth in val
    Serial.println(val);     // print value in Serial monitor

    if (val == 'A') {                 // check if data is 1
      digitalWrite(led_pin, HIGH);    // indicate that lights will be on using indicator led
      digitalWrite(relay_pin, HIGH);  // turn on relay
    }

    else if (val == 'a') {           // othervise data recieved is not 0 so turn off relay
      digitalWrite(led_pin, LOW);    // indicate that lights will be off using indicator led
      digitalWrite(relay_pin, LOW);  // turn off relay
    }
  }
}