#include "FastLED.h"

#define NUMBER_LEDS 60
#define STRIP_PIN 6

#define USE_SECOND_HALL 1

CRGB leds[NUMBER_LEDS];

// speed in rounds-per-millisecond
volatile float rpms = 0;

volatile unsigned long current_mus = 0;
volatile unsigned long current_loop_mus = 0;
volatile unsigned long last_mus = 0;
volatile unsigned long revolution_startmus = 0;
volatile byte current_pos = 0;
byte offset = 0;

void setup() {
  Serial.begin(115200);
  Serial.println("Started.");
  attachInterrupt(digitalPinToInterrupt(2), magnet_detect, RISING);//Initialize the intterrupt pin (Arduino digital pin 2)
#ifdef USE_SECOND_HALL
  attachInterrupt(digitalPinToInterrupt(3), magnet_detect2, RISING);
#endif
  FastLED.addLeds<WS2812B, STRIP_PIN, GRB>(leds, NUMBER_LEDS).setCorrection( TypicalLEDStrip );
  showPosition();
}

void loop() {
  current_loop_mus = micros();
  if((current_loop_mus - revolution_startmus) > 1000000) {
    revolution_startmus = current_loop_mus;
    rpms = 0;
    offset = current_pos;
  }

  current_pos = (int)((((float)(current_loop_mus - revolution_startmus)) / 1000.0) * rpms * NUMBER_LEDS + offset) % NUMBER_LEDS;
  showPosition();
  FastLED.delay(50);
}

void showPosition() {
  // show the led at position pos (NUMBER_LEDS must be < 256)!
  for (int i = 0; i < NUMBER_LEDS; i++) {
    leds[i] = CRGB::Black;
  }
  byte next = (current_pos + 1) % NUMBER_LEDS;
  byte prev = (current_pos -1)%NUMBER_LEDS;
  leds[current_pos] = CRGB::White;;
  leds[current_pos].fadeLightBy(32);
  leds[next] = CRGB::DarkOrange;
  leds[next].fadeLightBy(128);
  leds[prev] = CRGB::DarkOrange;
  leds[prev].fadeLightBy(128);
  FastLED.show();
}

void magnet_detect()//This function is called whenever a magnet/interrupt is detected by the arduino
 {
   Serial.println("detect");
   current_mus = micros();
 #ifndef USE_SECOND_HALL
   rpms = 1000.0 / (float)(current_mus - revolution_startmus );
 #else
 // half revolutions
   rpms = 500.0 / (float)(current_mus - revolution_startmus );
 #endif
   Serial.println(rpms, DEC);
   revolution_startmus = current_mus;
   current_pos = 0;
   offset = 0;
   //showPosition();
 }

 #ifdef USE_SECOND_HALL
void magnet_detect2()//This function is called whenever a magnet/interrupt is detected by the arduino
 {
   Serial.println("detect");
   current_mus = micros();
 // half revolutions
   rpms = 500.0 / (float)(current_mus - revolution_startmus );
   Serial.println(rpms, DEC);
   revolution_startmus = current_mus;
   //current_pos = 0;
   //offset = 0;
   //showPosition();
 }
 #endif