bt_led_controller.ino

/******************************************
 *    Control 3 LEDs using bluetooth      *
 *     EsperienzeElettroniche 2022        *
 ******************************************/
#include <SoftwareSerial.h>

/* Pins used for software serial connection */
#define rxPin 2
#define txPin 3

/* Pins used for LEDs */
#define ledA 4
#define ledB 5
#define ledC 6

/* Bluetooth / Serial connection speed */
#define baudrate 57600

/* Initalize software-emulated serial port (Bluetooth module) */
SoftwareSerial bt(rxPin, txPin);

char data;

void setup() {
  pinMode(ledA, OUTPUT);
  pinMode(ledB, OUTPUT);
  pinMode(ledC, OUTPUT);
  
  bt.begin(baudrate);
  Serial.begin(baudrate);
}

void loop() {
  /* Wait for Bluetooth or serial data */
  while(!bt.available() && !Serial.available())
    ;
    
  if(bt.available())
    data=bt.read();
  else
    data=Serial.read();

  /* Use received character to turn corresponding LED on or off */
  switch(data){
    case 'A':
      digitalWrite(ledA, 1);
      break;
    case 'a':
      digitalWrite(ledA, 0);
      break;
    case 'B':
      digitalWrite(ledB, 1);
      break;
    case 'b':
      digitalWrite(ledB, 0);
      break;
    case 'C':
      digitalWrite(ledC, 1);
      break;
    case 'c':
      digitalWrite(ledC, 0);
      break;
  }
}