// PWM2LED
// goebish 2017
//

#include <FastLED.h> // (lib available at https://github.com/FastLED/FastLED/archive/master.zip )
// see https://github.com/FastLED/FastLED/wiki/Pixel-reference for reference

// settings
#define NUM_LEDS 12

#define WS2812_pin 4 // ws2812 stripe Din

#define PWM_pin 3    // throttle PWM input

#define PWM_MIN     1000
#define PWM_NEUTRAL 1445
#define PWM_MAX     2000

// FastLed hue chart: http://i.imgur.com/0utnZcB.jpg
#define BRAKE_HUE   0  // red
#define NEUTRAL_HUE 160 // blue
#define ACCELERATE_HUE 96 // green

// end settings

CRGB leds[NUM_LEDS];

void setup() {
    // init PWM input
    pinMode(PWM_pin, INPUT_PULLUP);
    // init leds
    FastLED.addLeds<NEOPIXEL, WS2812_pin>(leds, NUM_LEDS);
    FastLED.showColor(CRGB::Black);
    delay(100);
}

void loop()
{
    // set leds hue according to throttle value
    uint8_t hue;
    uint16_t pwm = pulseIn(PWM_pin, HIGH);
    if (pwm >= PWM_NEUTRAL) { // accelerate
        hue = map(pwm, PWM_NEUTRAL, PWM_MAX, NEUTRAL_HUE, ACCELERATE_HUE);
    }
    else { // brake
        hue = map(pwm, PWM_NEUTRAL, PWM_MIN, NEUTRAL_HUE, BRAKE_HUE);
    }
    FastLED.showColor(CHSV(hue, 255, 255));
    delay(25);
}