I want some explanation the code
#include <Encoder.h>
#include <Adafruit_NeoPixel.h>
const int NUM_LEDS = 144; // number of leds in strip
const int LED_PIN = 5; // pin for led strip
const int BRIGHTNESS = 255; // brightness of all leds
const int WHEEL_SIZE = 256; // how many entries in the color wheel
const boolean MOVE_LIGHT = false; // move one light around or keep all lights on
const int ENCODER_PIN_1 = 1;
const int ENCODER_PIN_2 = 2;
const int ENCODER_BUTTON = 7;
Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, LED_PIN, NEO_RGB + NEO_KHZ800);
Encoder encoder(ENCODER_PIN_1, ENCODER_PIN_2);
int mode = 0;
long lastPush = 0;
int autoPosition = 0;
void initializeToBlack() {
for (int i =0; i < NUM_LEDS; i++) {
strip.setPixelColor(i, 0);
}
}
void setup() {
Serial.begin(9600);
pinMode(ENCODER_BUTTON, INPUT);
digitalWrite(ENCODER_BUTTON, HIGH); //turn pullup resistor on
strip.begin();
initializeToBlack();
strip.show();
}
long normalize(long value, long radix) {
long rval = value % radix;
if (rval < 0) return radix + rval;
else return rval;
}
void loop() {
int button= digitalRead(ENCODER_BUTTON);
if (button == 0) {
if ((millis() - lastPush) > 250) {
lastPush = millis();
mode++;
if (mode > 4) mode = 0;
}
}
long knobValue = encoder.read() / 2;
long ledPosition = normalize(knobValue, NUM_LEDS);
long colorValue = normalize(knobValue * 5, WHEEL_SIZE);
long sleepValue = abs(knobValue) % 500;
switch(mode) {
// off
case 0: initializeToBlack();
break;
// knob moves led
case 1: initializeToBlack();
strip.setPixelColor(ledPosition, colorWheel(BRIGHTNESS, colorValue));
break;
// all on, knob makes rainbow
case 2: for (int i =0; i < NUM_LEDS; i++) {
strip.setPixelColor(i, colorWheel(BRIGHTNESS, colorValue));
}
break;
// one auto moving light, knob adjusts speed
case 3:
delay(sleepValue);
initializeToBlack();
strip.setPixelColor(autoPosition, colorWheel(BRIGHTNESS, autoPosition * (WHEEL_SIZE / NUM_LEDS)));
autoPosition++;
if (autoPosition >= NUM_LEDS) {
autoPosition = 0;
}
break;
// slug of rainbow auto moving lights, knob adjusts speed
case 4:
const int SLUG_SIZE = 15;
delay(sleepValue);
initializeToBlack();
for (int i = 0; i < SLUG_SIZE; i++) {
strip.setPixelColor((i + autoPosition) % NUM_LEDS, colorWheel(BRIGHTNESS, i * (WHEEL_SIZE / SLUG_SIZE)));
}
autoPosition++;
if (autoPosition >= NUM_LEDS) {
autoPosition = 0;
}
break;
}
strip.show();
}
// given a wheel position in 0-255 range
// return a rainbow color adjusted by intensity 0 to 1.0
uint32_t colorWheel(float intensity, byte wheelPos)
{
const int WHEEL_THIRD = (WHEEL_SIZE - 1) / 3;
if (intensity < 0.0 ) intensity = 0.0;
if (intensity > 1.0) intensity = 1.0;
// as wheelPos progresses from 0 to 255 once, colorIndex should progress from 0 to 255 3 times
// find out position in current third of wheel then multiple by 3 to get full color value
byte colorIndex = (wheelPos % WHEEL_THIRD) * 3;
int fadeColor = (255 - colorIndex) * intensity; // color going down
int increaseColor = colorIndex * intensity; // color going up
switch (wheelPos / WHEEL_THIRD) {
case 0: // first third of the wheel, red fading, no green, blue increasing
return Adafruit_NeoPixel::Color(fadeColor, 0, increaseColor);
break;
case 1: // second third of the wheel no red, green increasing, blue fading
return Adafruit_NeoPixel::Color(0, increaseColor, fadeColor);
break;
case 2: // last third of the wheel, red increasing, green fading, no blue
return Adafruit_NeoPixel::Color(increaseColor, fadeColor, 0);
break;
}
}