Tiny fire simulation for QT Py or any FastLED-supporting board

FastLEDTinyFireSim.ino

// modeled after https://github.com/todbot/qtpy-tricks#fire-simulation-on-external-neopixel-strip
// must use latest FastLED checkout from https://github.com/FastLED/FastLED
// as FastLED 3.3.3 doesn't have QT Py support
#include "FastLED.h"
#define LED_PIN 0
#define NUM_LEDS 8

CRGB leds[NUM_LEDS];

void setup() { 
   FastLED.addLeds<WS2812, LED_PIN,GRB>(leds, NUM_LEDS);
   FastLED.setBrightness( 50 ); // out of 255
}

void loop() { 
  // dim all LEDs by (30,30,30)
  for(int i=0; i<NUM_LEDS; i++) {
    leds[i] -= CRGB(30,30,30);
  }
  // shift LEDs down by one
  for(int i=NUM_LEDS-1; i>0; i--) {
    leds[i] = leds[i-1];
  }  
  // set first LED to random fire color
  leds[0] = CRGB( random(150,255), random(50,100), 0);

  FastLED.show();
  delay(100);
}

Apologies, I was using the latest FastLED checkout from github, not the one in the Library Manager (the github checkout version is still 3.3.3, confusingly) And there hasn't been a FastLED full release yet with QT Py support.

If you are familiar with git you can use it to replace the FastLED library in your Arduino "libraries" directory. On a Mac in terminal this would look like:

cd $HOME/Documents/Arduino/libraries
rm -rf FastLED
git clone https://github.com/FastLED/FastLED

and then recompiling in the Arduino IDE.

In Windows and without git you can download a zipfile of the repository by clicking on the "Code" button and clicking "Download ZIP" (see screenshot below). Then place that zip file in your "Documents/Arduino/libraries" folder, right-click on it to Extract All, and then rename the resulting folder of "FastLED-master" to just "FastLED"

Thank you for the code.

I tried increasing the number of LEDs to 30, but it seems only 9 work.

Hi @Yousefff1,
You will need to decrease the amount of fading from CRGB(30,30,30) to something like CRGB(10,10,10)

Thank you! I'll test it out.

I appreciate it!