Arduino RGB LED Strip Controller

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Introduction: Arduino RGB LED Strip Controller

About: Software Developper by day, maker and learner by night/weekends ;)

I was curious about using RGB LED Strip, so I got one and decided to do a little controller to see what I can do with it... so here it is.

If you have any questions, comments, constructive criticism... don't hesitate to write :)

If you like my build, please like the video on YouTube and subscribe, it would be nice :)

Step 1: Components

Step 2: The Schematic

This is what the circuit looks like... I used "123D Circuits" by Autodesk.

They don't have an LED Strip component, so I replaced it with the RGB LED here... but never connect an LED to a 9V battery without resistance, you will blow the LED.

Now let's build it

Step 3: Voltage and Ground

Connect the voltage and the ground from your Arduino to the tracks of your breadboard.

Step 4: Potentiometers

Install the potentiometers on your breadboard

Step 5: Inputs

Connect the middle pin of you potentiometers to the analog pins A0, A1 and A2 of your Arduino, this will send a different voltage to the pins of the Arduino depending of the position of the potentiometer. Check the specs of your potentionmeters to know which pin is which.

Step 6: Potentiometers Voltages and Grounds

Connect the voltage and grounds to the potentiometers. Check the specs of your potentionmeters to know which pin is which.

Step 7: Transistors

Install the transistors on your breadboard. Google the model number of your transistor to know the pin configuration. Here you can find the documentation of the transistors I used, the BC547B, but don't rely on this for your transistors, because the pin configuration isn't standard.

Step 8: Outputs

Connect the "base" pin of your transistor to digital PWM pins on your Arduino, I used pins 3, 5 and 6. Those will send the desired current to the transistors to light up the amount of each colour (red, green and blue) separately.

Step 9: Transistors Grounds

Connect the "emitter" pins of your transistors to the ground. Again check the documentation of the transistor your are using to know the correct pin configuration.

Step 10: The Battery and the Strip

Finally, connect the "collector" pin of your transistors to the LED strip,check your strip to know which pin is which colour. Then connect your battery snap wires, black to the ground and red to the anode (positive) pins of the strip. Now we just need to program the Arduino and try it.

Step 11: The Code

This is the code to be able to run the controller. It's very basic, taking the value of the resistance coming from the potentiometers, limiting it and sending it to the LED strip via the transistors.

int const rPotPin = A2;
int const gPotPin = A1;
int const bPotPin = A0;

int const rOutPin = 3;
int const gOutPin = 5;
int const bOutPin = 6;

int rVal;
int gVal;
int bVal;

void setup()
{
  pinMode(rOutPin, OUTPUT);
  pinMode(gOutPin, OUTPUT);
  pinMode(bOutPin, OUTPUT);
}

void loop()
{
  rVal = analogRead(rPotPin) / 4;
  gVal = analogRead(gPotPin) / 4;
  bVal = analogRead(bPotPin) / 4;

  analogWrite(rOutPin, rVal);
  analogWrite(gOutPin, gVal);
  analogWrite(bOutPin, bVal);
}

Step 12: The Final Product

Here you can see some of the colours you can create with different potentiometer positions :)

Step 13: Here's How to Build It and What It Does

If you like my build, please like the video on YouTube and subscribe, it would be nice :)

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34 Discussions

Hello,

I am looking to build a (remarkably) similar circuit to this, however, I have been considering 9 volt batteries. What kind of resistance should I use (or how do i calculate it) in order to keep my arduino and leds safe?

Thanks!

Hi. My rgb led is glowing only on pink color, arduino uno

what are transistors used for? i'm very new to this arduino, but i want to learn alot :)

can I use this thing as a night lamp? do the transistors able to withstand workload of turned on for 8 hours each day? (assume that heatsink is on each of the transistors)

what if i change the power to 12v using power supply ?

1 reply

Well it depends on your led strip... if it takes 12 volts then sure go ahead

0
user
h0tm

1 year ago

you are using a random rgb led strip ?

1 reply

Well I specify the product number in the instructable

when I connect up the battery first, the led strip blinks and goes off. Why?

1 reply

i experienced the same thing when i connected the arduino and led strip to the same supply.

Try giving the arduino and the leds a different source ,it should work then.

Very nice!

How can you make it happen only on battery...

I need it for a show and I can't plug it to any kind of power supply..

Thanks!!

1 reply

powerbanks with dual usb out maybe, thats what i use

Great project. Worked first try. There is a slight flicker when it's on but nothing too noticable.

1 reply

It was the green flickering. I unplugged it from the breadboard and it has stopped. I still have no idea what it is. By the way my strip needs 12v and I am using a 12v power supply. The flicker gets worse with different colors. Could the limiter settings need changing?

How many LEDs you are able to glow using BC547B transistor? As per the spec, the transistor can support 100mA continuous current. As per my understanding, each segment of LED strip (comprising of 3 LEDs requires 60mA. But in the video i can see there are more than 3 LEDs glowing. Can you please provide more details on the LED strip? Also how much current is the strip consuming through the transistor?

Thanks.

4 replies

I was thinking the same, bc547 ic=100mA, so this should burnouts within very short time if we plug a led strip consist of even 20rgb leds

Well you got me there... I have no idea how much it is consuming. I could plug 2 strips in a row... so 100 LEDs and it was still working. Would I have fried the transistor after a while ? That's possible, I would have to build the thing again and make the measurements.

I think since you are using a 9V source, you might be saved. But you might not get true colors after some time as the battery voltage drops.
Do let me know what current ratings you are getting if possible? You can try connecting the led strip directly to the battery and check the current rating when each color is switched on and when all colors are on.

I'll have to check, unfortunately time is lacking these days, I don't even have time for my current project.

my code shows me 'rpotpin' was not declared in his scope

What should I do please

I using a spark fun led strip