Arduino

Bluetooth 220 V voltage switch

Control a household lamp with your smartphone.

Needed:

• Arduino board
• 5v relay for arduino (http://www.play-zone.ch/de/2-kanal-relais-modul-karte.html)
• bluetooth modem (https://www.sparkfun.com/products/12577)
• android sdk
• android phone
• jumper wires

connecting blue tooth modem to arduino

Important thing is that your modem supports 5v power. Many boards are built for 3v. Only four wires needed:

• Connect grd on arduino to grd on modem
• Connect 5v of arduio to vcc on modem
• Connect arduino digital pin 2 to tx on modem
• Connect arduino digital pin 3 to rx on modem

Do not use pins on arduino that have a tx and rx printed on them. They are used to communicate with your pc while connected by usb.

connecting relay to your arduino

This is straight forward too:

• Connect grd on arduino to grd on relay module.
• Connect 5v of arduino to vcc on relay module.
• Connect digital pin 13 to Ch1 or In1 on relay module.
• Connect digital pin 12 to Ch2 or In2 on relay module.
• e.c.t.

arduino code

Whenever a 40 (decimal) byte value is sent from smartphone, then the relay1 switches state. Whenever a 41 (decimal) byte value is sent from smartphone, then the relay2 switches state.

#include <SoftwareSerial.h>  
 

int relay1 = 13;
int relay2 = 12;
int bluetoothTx = 2;  
int bluetoothRx = 3;

int relay1on = 0;
int relay2on = 0;

SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);

// the setup routine runs once when you press reset:
void setup() {     
  

  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  
  Serial.begin(9600);  // Begin the serial monitor§§§§9600bps

  bluetooth.begin(115200);  // The Bluetooth Mate defaults to 115200bps
}

// the loop routine runs over and over again forever:
void loop() {
  if(bluetooth.available())  // If the bluetooth sent any characters
  {
    byte btInput = bluetooth.read();
    Serial.print((char)btInput);  
    
    if(btInput == 41)
    {
      if(relay1on == 0)
      {
       digitalWrite(relay1, HIGH);
       bluetooth.print("A1 ON");
       relay1on = 1;
       
      }
      else
      {
        digitalWrite(relay1, LOW);
         bluetooth.print("A1 OFF");
         relay1on = 0;
      }
    }
    if(btInput == 42)
    {
      if(relay2on == 0)
      {
       digitalWrite(relay2, HIGH);
       bluetooth.print("A2 ON");
       relay2on = 1;
      }
      else
      {
        digitalWrite(relay2, LOW);
         bluetooth.print("A2 OFF");
         relay2on = 0;
      }
    }
    
  }

  if(Serial.available())  // If stuff was typed in the serial monitor, for testing purposes.
  {
    // Send any characters the Serial monitor prints to the bluetooth
    bluetooth.print((char)Serial.read());
  }
}