Flickering Neopixel Candle
For my final project, I have decided to create a mock candle using the Arduino and a set of Neopixels. The idea of this project is for the Neopixels to mimic the flicker of a candle burning, essentially recreating the organic motion of a burning, flickering, and fluttering candle.
Materials
-Arduino Board
-USB (to connect Arduino board to laptop/computer)
-9V Battery
-9V Battery Snap connector
-1 piece of white computer paper
-Neopixels
-330K Resistor
-1 box with drawer
-1 medium to large mason jar with twist off cap
General materials:
-Duct tape
-Small drill bits
-Small screws
-Drill
-Solder wire
-Solder iron
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| Materials |
Set-Up
For the initial set-up, I had used a 9-piece Neopixel strip and soldered jumper wires to the according wire, making the black wire ground, orange Power, and the green Din. To the Din jumper, I had soldered on a 330K resistor. I then connected the wires to their corresponding placement on the Arduino board and uploaded the code, making adjustment to the code where needed.
Next, I had used a drill to attach the cap of the jar to the box itself. I then drilled a hole in the middle in order to string through the wires for the Arduino, which is located inside the box.
I then reconnected the wires to the Arduino and connected the 9V battery to the snap connector, plugging it into the Arduino to power the “candle”.
I had then used white paper in order to diffuse the light emitted by the Neopixels, making it seem more realistic and candle-like. Lastly, I screwed on the jar onto the cap attached to the box.
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| Finished Project |
Video:
Code:
#include <Adafruit_NeoPixel.h>
#define PIN 6
// color variables: mix RGB (0-255) for desired yellow
int redPx = 255;
int grnHigh = 85;
int bluePx = 5;
// animation time variables, with recommendations
int burnDepth = 15; //how much green dips below grnHigh for normal burn –
int flutterDepth = 10; //maximum dip for flutter
int cycleTime = 110; //duration of one dip in milliseconds
// pay no attention to that man behind the curtain
int fDelay;
int fRep;
int flickerDepth;
int burnDelay;
int burnLow;
int flickDelay;
int flickLow;
int flutDelay;
int flutLow;
Adafruit_NeoPixel strip = Adafruit_NeoPixel(9, PIN, NEO_GRB + NEO_KHZ800);
void setup() {
flickerDepth = (burnDepth + flutterDepth) / 2.4;
burnLow = grnHigh – burnDepth;
burnDelay = (cycleTime / 2) / burnDepth;
flickLow = grnHigh – flickerDepth;
flickDelay = (cycleTime / 2) / flickerDepth;
flutLow = grnHigh – flutterDepth;
flutDelay = ((cycleTime / 2) / flutterDepth);
strip.begin();
strip.show();
}
// In loop, call CANDLE STATES, with duration in seconds
// 1. on() = solid yellow
// 2. burn() = candle is burning normally, flickering slightly
// 3. flicker() = candle flickers noticably
// 4. flutter() = the candle needs air!
void loop() {
burn(25);
flicker(5);
burn(20);
flutter(3);
burn(3);
on(5);
burn(10);
flicker(5);
}
// basic fire funciton – not called in main loop
void fire(int grnLow) {
for (int grnPx = grnHigh; grnPx > grnLow; grnPx–) {
int halfGrn = grnHigh – ((grnHigh – grnPx) / 2);
int darkGrn = grnPx – 70;
darkGrn = constrain(darkGrn, 5, 255);
strip.setPixelColor(0, redPx-180, darkGrn, 0);
strip.setPixelColor(1, redPx-180, darkGrn, 0);
strip.setPixelColor(2, redPx-120, grnPx-50, bluePx-5);
strip.setPixelColor(3, redPx-60, grnPx-35, bluePx-2);
strip.setPixelColor(4, redPx, grnPx, bluePx);
strip.setPixelColor(5, redPx, grnPx, bluePx);
strip.setPixelColor(6, redPx, halfGrn, bluePx);
strip.setPixelColor(7, redPx, grnHigh, bluePx);
strip.show();
delay(fDelay);
}
for (int grnPx = grnLow; grnPx < grnHigh; grnPx++) {
int halfGrn = grnHigh – ((grnHigh – grnPx) / 2);
int darkGrn = grnPx-70;
darkGrn = constrain(darkGrn, 5, 255);
strip.setPixelColor(0, redPx-180, darkGrn, 0);
strip.setPixelColor(1, redPx-180, darkGrn, 0);
strip.setPixelColor(2, redPx-120, grnPx-50, bluePx-5);
strip.setPixelColor(3, redPx-60, grnPx-35, bluePx-2);
strip.setPixelColor(4, redPx, grnPx, bluePx);
strip.setPixelColor(5, redPx, grnPx, bluePx);
strip.setPixelColor(6, redPx, halfGrn, bluePx);
strip.setPixelColor(7, redPx, grnHigh, bluePx);
strip.show();
delay(fDelay);
}
}
// fire animation
void on(int f) {
fRep = f * 1000;
int grnPx = grnHigh – 6;
strip.setPixelColor(0, redPx-180, grnPx-70, 0);
strip.setPixelColor(1, redPx-180, grnPx-70, 0);
strip.setPixelColor(2, redPx-120, grnPx-50, bluePx-5);
strip.setPixelColor(3, redPx-60, grnPx-35, bluePx-2);
strip.setPixelColor(4, redPx, grnPx, bluePx);
strip.setPixelColor(5, redPx, grnPx, bluePx);
strip.setPixelColor(6, redPx, grnPx, bluePx);
strip.setPixelColor(7, redPx, grnHigh, bluePx);
strip.show();
delay(fRep);
}
void burn(int f) {
fRep = f * 8;
fDelay = burnDelay;
for (int var = 0; var < fRep; var++) {
fire(burnLow);
}
}
void flicker(int f) {
fRep = f * 8;
fDelay = burnDelay;
fire(burnLow);
fDelay = flickDelay;
for (int var = 0; var < fRep; var++) {
fire(flickLow);
}
fDelay = burnDelay;
fire(burnLow);
fire(burnLow);
fire(burnLow);
}
void flutter(int f) {
fRep = f * 8;
fDelay = burnDelay;
fire(burnLow);
fDelay = flickDelay;
fire(flickLow);
fDelay = flutDelay;
for (int var = 0; var < fRep; var++) {
fire(flutLow);
}
fDelay = flickDelay;
fire(flickLow);
fire(flickLow);
fDelay = burnDelay;
fire(burnLow);
fire(burnLow);
}