Published July 3, 2020 © MIT

Blink LED via Mobile Bluetooth

We access the bluetooth module to relay information and convey it via switching LED on/off.

BeginnerProtip5,221

Things used in this project

Hardware components

HC-05 Bluetooth Module

Male/Female Jumper Wires

Arduino UNO R3

Software apps and online services

Arduino IDE

Arduino bluetooth controller

Story

Here, we learn how to plug-in a Bluetooth module and communicate via our android smartphone. This is a simple application anyone can learn and also use for bigger projects.

Working

The bluetooth module gets the characters sent via the application and passes it to the arduino board via transmitter. We read these characters and code a simple logic of turning LED on/off.

Bluetooth module

This module is a stand-alone module, which can connect to any hardware via bluetooth. The first time one connects we need to enter the pass key, which is 1234. I paired the first time via the bluetooth setting in my smartphone.

Uploading the sketch

Do not connect the TX and RX on Arduino while uploading the sketch. We get an error referring to non-sync, if we try to upload the sketch while the TX, RX pins are connected.

Testing the project

Finally, after we have uploaded the sketch successfully, we then make the necessary connections from the Bluetooth module to the Arduino board. We then run the app and connect to HC-05 module. Then we can enter the characters from the terminal tab in the app.

We can have the serial monitor open to check if we are receiving the characters correctly.

Code

bt_blink

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available()>0)
   {     
      char data= Serial.read(); // reading the data received from the bluetooth module
      switch(data)
      {
        case '1': 
        {
          digitalWrite(LED_BUILTIN, HIGH);
          break;
        }
        case '2': 
        {
          digitalWrite(LED_BUILTIN, LOW);
          break;
        }
        default : break;
      }
      Serial.println(data);
   }
   delay(50);     
}

Credits

Bhaskar C

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Happy to learn!

Blink LED via Mobile Bluetooth

Things used in this project

Hardware components

Software apps and online services

Story

Working

Bluetooth module

Uploading the sketch

Testing the project

Schematics

Schematics

Code

bt_blink

Credits

Bhaskar C

Comments

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Blink LED via Mobile Bluetooth

Blink LED via Mobile Bluetooth

Things used in this project

Hardware components

Software apps and online services

Story

Working

Bluetooth module

Uploading the sketch

Testing the project

Schematics

Schematics

Code

bt_blink

Credits

Bhaskar C

Comments

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