Realistic Flickering Flame Effect With Arduino and LED's

In this project we will use 3 LED's and an Arduino to create a realistic fire effect that could be used in a diorama, model railway or a fake fireplace in your home or put one inside a frosted glass jar or tube and no-one would know it wasn't a real candle inside.

This is a really simple project suited to beginners.

Step 1: Step 1 - Wire Up the LED's

Wire up 3 LED's. Use 2 x Diffused Yellow and 1 x Diffused RED. You can increase the number of LED's if you wanted a larger or brighter display. Consider the use of transistors if your amperage will go over that which can be supplied by the Arduino.

Use resistors that suit your particular type of LED.

Step 2: Enter the Code

Enter this code:

// LED Fire Effect

int ledPin1 = 10;
int ledPin2 = 9;
int ledPin3 = 11;

void setup()
{
pinMode(ledPin1, OUTPUT);
pinMode(ledPin2, OUTPUT);
pinMode(ledPin3, OUTPUT);
}

void loop() {
analogWrite(ledPin1, random(120)+135);
analogWrite(ledPin2, random(120)+135);
analogWrite(ledPin3, random(120)+135);
delay(random(100));
}

Step 3: Upload and Run

Upload the code to the Arduino and run it. You will now have a pretty realistic flame/fire effect from the LED's. Bounce the light off a white card or a mirror to achieve the full effect.

Step 4: Video of the Effect

Video of the effect. The colours and the effect don't show up very well in the video. In real life it is a very effective flame effect. Give it a try.

Comments

[rastita]

Hi! thanks you very much... i was coding something very complex and you gave us a very simple but efective candle efect ;)

Instead of a full Arduino, i used an ATTiny85, and added a swich...

Thanks a lot!

[LightsAction]

Do you have a circuit diagram by any chance?

[metalhead8711]

hi rastita. this is a very awesome project you created. im interested how you wired it. it. code uses two leds but i see four. lol unless the others are just there. i see you connected leds with resistors on pins 5 and 6. your battery case looks like it takes two 1.5V batteries. AA or AAA? truly and awesome project.

[n71]

Hey Rastita, can you provide the code? Superthanx!

[rastita]

Yeah! for shure.... but it´s almost the same than the original :)

But only using 2 leds, instead of 3...

// LED Fire Effect

int ledPin1 = 5;

int ledPin2 = 6;

//int ledPin3 = 11;

void setup()

{

pinMode(ledPin1, OUTPUT);

pinMode(ledPin2, OUTPUT);

//pinMode(ledPin3, OUTPUT);

}

void loop() {

analogWrite(ledPin1, random(80)+35);

analogWrite(ledPin2, random(120)+135);

//analogWrite(ledPin3, random(120)+135);

delay(random(100));

}

[n71]

Actually there could be 3 random flickers + 2 random fading using PWM on pins 0 and 1 with bursts to simulate little flame with occasional crackers. :-)

[goldenshuttle]

Very simple; & very impressive..

[doktorvortexx]

Thanks for the great Instructable! Saved me a bunch of time writing the code myself!

[0_Nvd_0]

Very COOL Earthshine. You have invented a very nice thing.

[TheArduinoGuy]

Thanks

[anorchis2]

왜 0~255가 아니가 0~120을 해서 135를 더한 거예요?

[altheimallan]

Thanks for the circuit, works well with 3 LEDs. Have used 3 sets of LEDs and obviously to much current as fails after some use. You mention the use of transistors, do you have further info on that circuitry.

Thank you,

Allan

[Nayth-D]

Could I use this code to control lets say 16 3mm 3v Leds? I want to add leds to the thrusters on a model kit and want them to have this flickering effect? I have an arduino UNO.

[TheArduinoGuy]

Yes that would work as long as you have enough current to power all 16 LEDs. You may need to power them from an external source and use the Arduino to control them via transistors or something like that as it is unlikely you'll get enough current from the Arduino pins for that many LEDs.

[DavidB552]

question if I put a 5 or 10k pot on the ground line back to the uno could I get varriable brightness of candle or will it break everything ?

[TheArduinoGuy]

That will also reduce voltage to the Arduino, so yeah it will totally break everything.

[DavidB552]

Sorry I mean the ground going from all 3 leds back to the Arduino?

[TheArduinoGuy]

It would sorta work but it is not ideal as each LED is meant to have it's own current limiting resistor. It would be a lot easier to do it in code using the PWM functions.

[sayville882]

Thanks. Very elegant coding.

[AJ Sikes]

Brilliant. This is just what I've needed for a dollhouse project. Thanks!