Published October 17, 2022 © CERN-OHL

arduino-bluetooth-rgb-led-control-using-android-app

Hello all, in this project I will control RGB led using Bluetooth.

IntermediateFull instructions provided1,682

arduino-bluetooth-rgb-led-control-using-android-app

Things used in this project

Hardware components

Arduino UNO

HC-05 Bluetooth Module

RGB Diffused Common Cathode

Resistor 220 ohm

Jumper wires (generic)

Story

RGB LEDs play a large part in applications like outdoor decoration lighting in cities, stage lighting designs, home decoration lighting and LED display matrix. Recently, RGB color mixing technology can also be found in LCD backlighting and projectors.
In this tutorial we will learn how the RGB LED works and how we can control RGB led using HC-05 Bluetooth module, Arduino IDE and an Android application.
What is RGB LED?
RGB LED is actually three LEDs, red, green, and blue inside one package. Three PWM Outputs are used to control the RGB LED. A PWM value of 0.0 would be off and a 1.0 full on for each color LED. This allows a program to vary both the color and brightness level of the LED.
Typically an RGB LED has four pins. One common pin and one for each of the three LEDs. In the LED seen below, the common pin is the longest pin. The RGB LED can be classified as either common anode or common cathode. The common pin in the common anode RGB LED is connected to VCC while in the common cathode it is connected to the ground.
NOTE: Red, Green and Blue are called primary colors and by mixing each other with different intensity we may get millions of color outcomes. This is the basic concept of the RGB led.
Connecting the RGB LED and HC-05 Bluetooth module to Arduino
VCC – to VCC of Arduino.
GND – to GND of Arduino.
RX – to digital pin 0(TX pin) of Arduino.
TX – to digital pin 1(RX pin) of Arduino.
Note:
i).Connect RX and TX pins after uploading the code
ii).The terminals of the RGB LED should be connected to PWM pins of the Arduino.
Android App used for Arduino RGB led Bluetooth control
For this project we use Arduino RGB Led Control app which is got from the Google play store. This Application enables us to connect the phone and the Arduino board through Bluetooth.
You can get the Application from here

After connecting the circuit , now you can upload the code and test the 
output results.

Code

BT control RGB led

#include <SoftwareSerial.h>
#include <Wire.h>
SoftwareSerial mySerial(0,1); // RX and TX pins
int PIN_RED = 9;
int PIN_GREEN = 10;
int PIN_BLUE = 11;
String RGB = "";
String RGB_Previous = "255.255.255";
String ON = "ON";
String OFF = "OFF";
boolean RGB_Completed = false;
void setup()
{
pinMode (PIN_RED, OUTPUT);
pinMode (PIN_GREEN, OUTPUT);
pinMode (PIN_BLUE, OUTPUT);
Serial.begin(9600);
mySerial.begin(9600);
RGB.reserve(30);
}
void loop()
{
while(mySerial.available())
{
char ReadChar = (char)mySerial.read();
if(ReadChar == ')')
{
RGB_Completed = true;
}else{
RGB += ReadChar;
}
}
if(RGB_Completed)
{
Serial.print("RGB:");
Serial.print(RGB);
Serial.print(" PreRGB:");
Serial.println(RGB_Previous);
if(RGB==ON)
{
RGB = RGB_Previous;
Light_RGB_LED();
}
else if(RGB==OFF)
{
RGB = "0.0.0";
Light_RGB_LED();
}else{
Light_RGB_LED();
RGB_Previous = RGB;
}
RGB = "";
RGB_Completed = false;
}
}
void Light_RGB_LED()
{
int SP1 = RGB.indexOf(' ');
int SP2 = RGB.indexOf(' ', SP1+1);
int SP3 = RGB.indexOf(' ', SP2+1);
String R = RGB.substring(0, SP1);
String G = RGB.substring(SP1+1, SP2);
String B = RGB.substring(SP2+1, SP3);
Serial.print("R=");
Serial.println( constrain(R.toInt(),0,255));
Serial.print("G=");
Serial.println(constrain(G.toInt(),0,255));
Serial.print("B=");
Serial.println( constrain(B.toInt(),0,255));
analogWrite(PIN_RED, (R.toInt()));//comment if colors are inverted
analogWrite(PIN_GREEN, (G.toInt()));//and uncomment part below.
analogWrite(PIN_BLUE, (B.toInt()));
// analogWrite(PIN_RED, (255-R.toInt()));//uncomment if colors are inverted
// analogWrite(PIN_GREEN, (255-G.toInt()));//and comment above part.
// analogWrite(PIN_BLUE, (255-B.toInt()));
}

Credits

Rayan kiwan

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arduino-bluetooth-rgb-led-control-using-android-app

Things used in this project

Hardware components

Story

Schematics

Bluetooth Control RGB led

Code

BT control RGB led

Credits

Rayan kiwan

Comments

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arduino-bluetooth-rgb-led-control-using-android-app

arduino-bluetooth-rgb-led-control-using-android-app

Things used in this project

Hardware components

Story

Schematics

Bluetooth Control RGB led

Code

BT control RGB led

Credits

Rayan kiwan

Comments

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