Arduino Bluetooth Basics

Categories:DIY Projects
[tabby title=”Overview”] This video will show you the basics of controlling an Arduino through bluetooth. Click the “Step” tags for a walkthrough!

[tabby title=”Step 1″]

Acquiring the Parts
Here’s what you will need:

  • A Bluetooth Capable Smartphone (I’ll be using an Android).
  • An Arduino ($10.99)
  • An Arduino Bluetooth Module ($6.45)
  • An LED ($0.99)
[tabby title=”Step 2″]


You can download the Fritzing sketch here.

Screen Shot 2014-03-08 at 7.38.33 PM

[tabby title=”Step 3″]



A good Android program for Arduino is called Ardudroid on the Google Play store.


int ledPin = 13; 
int state = 0;
int flag = 0; 
void setup() {
 pinMode(ledPin, OUTPUT);
 digitalWrite(ledPin, LOW);
 Serial.begin(9600); // Default connection rate for my BT module
void loop() {

 if(Serial.available() > 0){
 state =;

 if (state == '0') {
 digitalWrite(ledPin, LOW);
 if(flag == 0){
 Serial.println("LED: off");
 flag = 1;

 else if (state == '1') {
 digitalWrite(ledPin, HIGH);
 if(flag == 0){
 Serial.println("LED: on");
 flag = 1;
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  1. edmandowling
    March 22, 2016 at 5:30 pm

    Hi, I have done the set up as shown and I have connected the bluetooth module to my phone but when I try send information to turn off the LED, nothing happens. It I have the LED set HIGH in setup and try to turn it off via blutooth nothing happens. Any advice how to solve this for me?

  2. schwad
    July 9, 2016 at 6:22 pm

    I am having the same problem as edmandowling. I am using the HC-06, will this make any difference?

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