Published January 16, 2025

Bluetooth RGB LED Controller for iPhone & Android

It is an engaging Arduino project that empowers users to control an RGB LED strip via Bluetooth using their iPhone or Android device.

IntermediateFull instructions provided245

Bluetooth RGB LED Controller for iPhone & Android

Things used in this project

Hardware components

Arduino Nano R3

HM-10

Power Supply 5V 8A

Digilent WS2812 Addressable LED Strip

2m, 60LED/1m, IP30

Resistor 220 ohm

Resistor 100 ohm

Software apps and online services

STEMpedia Dabble

Hand tools and fabrication machines

Soldering iron (generic)

3D Printer (generic)

(Highly optional)

Story

Are you annoyed by those cheap RGB LED strips you see advertised online? I am too. That’s why I decided to create an easy-to-use RGB LED strip controller with Bluetooth that you can modify anytime you want. While the strips sold online can sometimes be decent, they’re usually not customizable enough to suit individual tastes. With my project, you get full control.

How to Use

If you’ve recreated my project or made your own version, here’s what to do:

Check your hardware: Make sure everything is connected and working.
Download the Dabble app on your smartphone.
Connect your Bluetooth module to your phone.
Open the Terminal function in the app, where you can type commands to control your RGB LED strip.

Commands You Can Use

Colors

Type any of these to change the color of the strip:

RED, GREEN, BLUE, YELLOW, MAGENTA, WHITE, ORANGE, PURPLE, GOLD, SKYBLUE, KHAKI, INDIGO, VIOLET, CRIMSON, LIME, TEAL, MAROON, SPRINGGREEN, MIDNIGHTBLUE, FORESTGREEN, PERU, ORCHID.

Animations

These commands trigger animations:

PARTY, CYLON, SEA.

Brightness

To adjust the brightness, type BRIGHTNESS followed by a number between 0 and 255.

Example: BRIGHTNESS 255 sets it to maximum brightness, while BRIGHTNESS 128 gives medium brightness.

Turning Off

To turn off the LEDs before starting a new color or animation, just type OFF. After that, you can enter a new command.

Parts I Used

Arduino Nano

I went with the Nano because it’s cheap and does the job. The only downside is its small SRAM, which fills up quickly with complex animations. My setup, with a few animations and colors, works fine, but if you want to do more advanced stuff, I recommend using an ESP32 instead.

LED Strip

I chose the WS2812B LED strip because it’s affordable, widely available, and pretty high quality for the price. I used a 5V, 2m, 60 LEDs per meter, IP30 strip.

If you’re using longer or denser strips, make sure you have a power supply that can handle the extra current.
Waterproofing (IP65 or higher) isn’t important for me because I’m using it indoors.

HM-10 Bluetooth Module

This module uses Bluetooth Low Energy (BLE), which works on both iOS and Android. Its best feature is cross-platform compatibility. The only downside is that it communicates using 3.3V logic, so you’ll need a voltage divider (I’ve included it in the schematic).

Power Supply

To calculate the power needed:

To find the optimal Power supply, you should evaluate how much power will your strip use. For example, my strips has 120 leds in total, while one led consumes around 60mA. Afterwards the math is simple, 60mA * 120 leds = 7, 2A. My strip is using 5V, so for total power, we use the formula: P = I*U. Total power consumed for my strip is 36W. I got a 40W power supply, so that is totally good enough for me (other parts use low levels of power). It’s always better to get a slightly larger power supply than you need. A smaller one could cause issues like dim LEDs or unstable behavior.

Voltage Divider

The HM-10’s RX pin works with 3.3V signals, but the Arduino sends 5V. To fix this, I used a voltage divider with two resistors. The formula for calculating the resistor values is:

Vout=Vin×(R2/R1+R2)

Code

I used the FastLED library, which is easy to work with. To set it up, you just need to tell the library how many LEDs you’re using, which pin they’re connected to, and the type of LED strip.

Customizing Colors and Animations:If you want to add or change colors, you can find a list of predefined colors here. You can also create your own animations by modifying the code.

Adjusting Brightness:The code includes a brightness command so you can change the brightness anytime without touching the hardware.

I won’t bore you with too many code details here, but if you have any questions, feel free to reach out—I’d be happy to help. 😀

Why I Chose Dabble

I used the Dabble app because it has a Terminal function where you can send commands directly to the Bluetooth module. It’s much more flexible than other apps that limit you with preset options. Dabble lets you get creative with colors, animations, and brightness.

Final Thoughts

This is my first published Arduino project, and I think it turned out great! I’m already thinking about upgrading it with an ESP32 for more advanced features, but for now, this version is enough for my needs.

Thanks for reading! If you have suggestions or feedback, I’d love to hear them. 😀

Here are some photos:

1 / 3

Custom parts and enclosures

Sketchfab still processing.

Schematics

Code

Led Control

#define CUSTOM_SETTINGS
#define INCLUDE_TERMINAL_MODULE
#include <Dabble.h>
#include <FastLED.h>

#define LED_PIN 6
#define NUM_LEDS 120
CRGB leds[NUM_LEDS];
uint8_t paletteIndex = 0;
uint8_t colorIndex[NUM_LEDS];
String currentAnimation = "";  // Keeps track of the active animation
uint8_t    numdots =   4;                                     // Number of dots in use.
uint8_t   thisfade =   2;                                     // How long should the trails be. Very low value = longer trails.
uint8_t   thisdiff =  16;                                     // Incremental change in hue between each dot.
uint8_t    thishue =   0;                                     // Starting hue.
uint8_t     curhue =   0;                                     // The current hue
uint8_t    thissat = 255;                                     // Saturation of the colour.
uint8_t thisbright = 255;                                     // How bright should the LED/display be.
uint8_t   thisbeat =   5;    
CRGBPalette16 currentPalette;                                 // Use palettes instead of direct CHSV or CRGB assignments
CRGBPalette16 targetPalette;                                  // Also support smooth palette transitioning
TBlendType    currentBlending;    
DEFINE_GRADIENT_PALETTE(club_gp) {
  0, 255, 0, 255,
  64, 186, 85, 211,
  128, 147, 112, 219,
  192, 123, 104, 238,
  255, 100, 76, 204,
};

CRGBPalette16 club = club_gp;


void setup() {
  Serial.begin(9600);
  Dabble.begin(9600);
  currentPalette  = CRGBPalette16(CRGB::Black);
  targetPalette   = club_gp;
  currentBlending = LINEARBLEND;  
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
  FastLED.clear();
  FastLED.show();

  for (int i = 0; i < NUM_LEDS; i++) {
    colorIndex[i] = random8();
  }

  Serial.println("Setup complete. Waiting for commands...");
}
String readCommand() {
    String command = "";  
    while (Terminal.available()) {
        char c = Terminal.read();  
        if (c == '\n' || c == '\r') break;  
        command += c;  
    }
    return command;
}
void loop() {
  Dabble.processInput(); 

 
  if (Terminal.available()) {
    String command = readCommand();
    command.trim();
    processCommand(command);  
  }

 
 else if (currentAnimation == "PARTY") {
    animateParty();
  } else if (currentAnimation == "CYLON") {
    animateCylon();
  }
  else if (currentAnimation == "SEA") {
    animateSea();
  }
}
void processCommand(String cmd) {
    cmd.toUpperCase();  

 if (cmd == "PARTY") {
        currentAnimation = "PARTY"; 
    }    else if (cmd.startsWith("BRIGHTNESS")) {
   
        int spaceIndex = cmd.indexOf(' ');
        if (spaceIndex != -1) {
            String brightnessValue = cmd.substring(spaceIndex + 1);
            int brightness = brightnessValue.toInt();
            if (brightness >= 0 && brightness <= 255) {
                FastLED.setBrightness(brightness);
                FastLED.show();
            } 
        } 
        return;
    }else if (cmd == "CYLON") {
        currentAnimation = "CYLON";  
    } else if (cmd == "SEA") {
        currentAnimation = "SEA";  
    }  else if (cmd == "OFF") {
        currentAnimation = "";  
        setColor(CRGB::Black);
    } else if (cmd == "RED") {
        currentAnimation = "";
        setColor(CRGB::Red);
    } else if (cmd == "GREEN") {
        currentAnimation = "";
        setColor(CRGB::Green);
    } else if (cmd == "BLUE") {
        currentAnimation = "";
        setColor(CRGB::Blue);
    } else if (cmd == "YELLOW") {
        currentAnimation = "";
        setColor(CRGB::Yellow);
    } else if (cmd == "MAGENTA") {
        currentAnimation = "";
        setColor(CRGB::Magenta);
    }  else if (cmd == "WHITE") {
        currentAnimation = "";
        setColor(CRGB::White);
    } else if (cmd == "ORANGE") {
        currentAnimation = "";
        setColor(CRGB::Orange);
    } else if (cmd == "PURPLE") {
        currentAnimation = "";
        setColor(CRGB::Purple);
    } else if (cmd == "GOLD") {
        currentAnimation = "";
        setColor(CRGB::Gold);
    } else if (cmd == "SKYBLUE") {
        currentAnimation = "";
        setColor(CRGB::DeepSkyBlue);
    } else if (cmd == "KHAKI") {
        currentAnimation = "";
        setColor(CRGB::Khaki);
    } else if (cmd == "INDIGO") {
        currentAnimation = "";
        setColor(CRGB::Indigo);
    } else if (cmd == "VIOLET") {
        currentAnimation = "";
        setColor(CRGB::Violet);
    } else if (cmd == "CRIMSON") {
        currentAnimation = "";
        setColor(CRGB::Crimson);
    }  else if (cmd == "LIME") {
        currentAnimation = "";
        setColor(CRGB::Lime);
    } else if (cmd == "TEAL") {
        currentAnimation = "";
        setColor(CRGB::Teal);
    } else if (cmd == "MAROON") {
        currentAnimation = "";
        setColor(CRGB::Maroon);
    }  else if (cmd == "SPRINGGREEN") {
        currentAnimation = "";
        setColor(CRGB::SpringGreen);
    }   else if (cmd == "MIDNIGHTBLUE") {
        currentAnimation = "";
        setColor(CRGB::MidnightBlue);
    } else if (cmd == "FORESTGREEN") {
        currentAnimation = "";
        setColor(CRGB::ForestGreen);
    }  else if (cmd == "PERU") {
        currentAnimation = "";
        setColor(CRGB::Peru);
    }  else if (cmd == "ORCHID") {
        currentAnimation = "";
        setColor(CRGB::Orchid);
    }    else {
        Serial.println("Unknown command: " + cmd);
    }
}


void animateSea() {
    static uint32_t lastUpdate = 0;
    static uint8_t waveIndex = 0;  

  
    CRGBPalette16 seaPalette = CRGBPalette16(
        CRGB::DeepSkyBlue,   
        CRGB::Aqua,          
        CRGB::Aquamarine,         
        CRGB::Blue           
    );


    if (millis() - lastUpdate > 50) {
        lastUpdate = millis();

        for (int i = 0; i < NUM_LEDS; i++) {
            uint8_t colorIndex = sin8(waveIndex + (i * 10)); 
            leds[i] = ColorFromPalette(seaPalette, colorIndex, 255, LINEARBLEND);
        }

        waveIndex += 4;  
        FastLED.show();
    }
}

void animateCylon() {
    static uint32_t lastUpdate = 0;

   
    if (millis() - lastUpdate > 50) {
        lastUpdate = millis();

     
        if (currentAnimation != "CYLON") {
            return; 
        }

     
        EVERY_N_MILLISECONDS(100) { 
            uint8_t maxChanges = 24;
            nblendPaletteTowardPalette(currentPalette, targetPalette, maxChanges);
        }

        ChangeMe();
        juggle_pal();
        FastLED.show();  
    }
}

void animateParty() {
  static uint32_t lastUpdate = 0;
  if (millis() - lastUpdate > 50) { 
    lastUpdate = millis();
    leds[random8(0, NUM_LEDS)] = ColorFromPalette(club, random8(), 255, LINEARBLEND);
    fadeToBlackBy(leds, NUM_LEDS, 1);
    FastLED.show();
  }
}

void setColor(CRGB color) {
  fill_solid(leds, NUM_LEDS, color);
  FastLED.show();
}
void juggle_pal() {                                           
  
  curhue = thishue;                                           
  fadeToBlackBy(leds, NUM_LEDS, thisfade);
  
  for( int i = 0; i < numdots; i++) {
    leds[beatsin16(thisbeat+i+numdots,0,NUM_LEDS)] += ColorFromPalette(currentPalette, curhue , thisbright, currentBlending);    // Munge the values and pick a colour from the palette
    curhue += thisdiff;
  }
  
}



void ChangeMe() {                                             // A time (rather than loop) based demo sequencer. This gives us full control over the length of each sequence.
  
  uint8_t secondHand = (millis() / 1000) % 30;                // IMPORTANT!!! Change '30' to a different value to change duration of the loop.
  static uint8_t lastSecond = 99;                             // Static variable, means it's only defined once. This is our 'debounce' variable.
  
  if (lastSecond != secondHand) {                             // Debounce to make sure we're not repeating an assignment.
    lastSecond = secondHand;
    switch(secondHand) {
      case  0: numdots = 1; thisbeat = 20; thisdiff = 16; thisfade = 2; thishue = 0; break;                  // You can change values here, one at a time , or altogether.
      case 10: numdots = 4; thisbeat = 10; thisdiff = 16; thisfade = 8; thishue = 128; break;
      case 20: numdots = 8; thisbeat =  3; thisdiff =  0; thisfade = 8; thishue=random8(); break;           // Only gets called once, and not continuously for the next several seconds. Therefore, no rainbows.
      case 30: break;
    }
  }
  
}

Credits

Azuolas

1 project • 0 followers

I am a first-year Automation and Control student at KTU, interested in Arduino projects and striving to optimize my environment!

Contact

Comments

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Bluetooth RGB LED Controller for iPhone & Android

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

How to Use

Commands You Can Use

Colors

Animations

Brightness

Turning Off

Parts I Used

Arduino Nano

LED Strip

HM-10 Bluetooth Module

Power Supply

Voltage Divider

Code

Why I Chose Dabble

Final Thoughts

Custom parts and enclosures

Lid

Box

Latch

Schematics

Schematic

Schematic

Code

Led Control

Credits

Azuolas

Comments

Embed the widget on your own site

Bluetooth RGB LED Controller for iPhone & Android

Bluetooth RGB LED Controller for iPhone & Android

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

How to Use

Commands You Can Use

Colors

Animations

Brightness

Turning Off

Parts I Used

Arduino Nano

LED Strip

HM-10 Bluetooth Module

Power Supply

Voltage Divider

Code

Why I Chose Dabble

Final Thoughts

Custom parts and enclosures

Lid

Box

Latch

Schematics

Schematic

Schematic

Code

Led Control

Credits

Azuolas

Comments

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