Skip to content

Bluetooth control Bulb with arduino Uno and bluetooth module

Hey!!! Now i will show you how to make Bluetooth controlled Bulb with arduino Uno and Bluetooth module Here home appliances are controlled by smart phone with help of the Bluetooth module (HC-05) and Arduino Bluetooth control apk. You can download this application (Arduino Bluetooth Control) from the google play store.
App download link:- Arduino Bluetooth Control Apk.
arduinot bluetooth contol car 
In this project bulb is controlled by the mobile through bluetooth module. 

  • 1. Arduino Uno Board
  • 2. HC-05 (Bluetooth)
  • 3. Relay Module
  • 4. Bulb holder
  • 4. Bulb
  • 5. 9v batteries or 5v adapter
  • 6.Connecting wires as per required
Bluetooth controlled Bulb

Bluetooth controlled Bulb
  • Make the connections as shown in the circuit diagram and in this Bluetooth controlled bulb Bluetooth module (HC-05) RX and TX pins are directly connected to the arduino uno TX and RX pins respectively. 
  • Here we are using 4 channel relay module, VCC and GND of relay module is connected to the voltage source from the arduino uno. 
  • And channel-1 is connected to the pin 3 of the arduino uno. 
  • Bulb and power supply (240v, 50Hz) is connected to the relay-1 of the relay module as shown in circuit diagram.


Click here to DOWNLOAD



String inputs;
#define relay1 2 //Connect relay1 to pin 9
#define relay2 3 //Connect relay2 to pin 8
#define relay3 4 //Connect relay3 to pin 7
#define relay4 5 //Connect relay4 to pin 6
#define relay5 6 //Connect relay5 to pin 5
#define relay6 7 //Connect relay6 to pin 4
#define relay7 8 //Connect relay7 to pin 3
#define relay8 9 //Connect relay8 to pin 2
void setup()
Serial.begin(9600); //Set rate for communicating with phone
pinMode(relay1, OUTPUT); //Set relay1 as an output
pinMode(relay2, OUTPUT); //Set relay2 as an output
pinMode(relay3, OUTPUT); //Set relay1 as an output
pinMode(relay4, OUTPUT); //Set relay2 as an output
pinMode(relay5, OUTPUT); //Set relay1 as an output
pinMode(relay6, OUTPUT); //Set relay2 as an output
pinMode(relay7, OUTPUT); //Set relay1 as an output
pinMode(relay8, OUTPUT); //Set relay2 as an output
digitalWrite(relay1, LOW); //Switch relay1 off
digitalWrite(relay2, LOW); //Swtich relay2 off
digitalWrite(relay3, LOW); //Switch relay1 off
digitalWrite(relay4, LOW); //Swtich relay2 off
digitalWrite(relay5, LOW); //Switch relay1 off
digitalWrite(relay6, LOW); //Swtich relay2 off
digitalWrite(relay7, LOW); //Switch relay1 off
digitalWrite(relay8, LOW); //Swtich relay2 off
void loop()
while(Serial.available()) //Check if there are available bytes to read
delay(10); //Delay to make it stable
char c =; //Conduct a serial read
if (c == ‘#’){
break; //Stop the loop once # is detected after a word
inputs += c; //Means inputs = inputs + c
if (inputs.length() >0)

if(inputs == “A”)

digitalWrite(relay1, LOW);
else if(inputs == “a”)
digitalWrite(relay1, HIGH);
else if(inputs == “B”)
digitalWrite(relay2, LOW);
else if(inputs == “b”)
digitalWrite(relay2, HIGH);
else if(inputs == “C”)

digitalWrite(relay3, LOW);
else if(inputs == “c”)
digitalWrite(relay3, HIGH);
else if(inputs == “D”)
digitalWrite(relay4, LOW);
else if(inputs == “d”)
digitalWrite(relay4, HIGH);
else if(inputs == “E”)

digitalWrite(relay5, LOW);

else if(inputs == “e”)
digitalWrite(relay5, HIGH);
else if(inputs == “F”)
digitalWrite(relay6, LOW);
else if(inputs == “f”)
digitalWrite(relay6, HIGH);
else if(inputs == “G”)

digitalWrite(relay7, LOW);
else if(inputs == “g”)
digitalWrite(relay7, HIGH);
else if(inputs == “H”)
digitalWrite(relay8, LOW);
else if(inputs == “h”)
digitalWrite(relay8, HIGH);


Leave a Reply

Your email address will not be published. Required fields are marked *