#include <FastLED.h>

// FASTLED
#define NUM_LEDS             256
#define DATA_PIN             13  

#define MAX_BRIGHTNESS      200
#define MIN_BRIGHTNESS       50
#define FRAMES_PER_SECOND    60

#define  ROWS 16
#define  COLS 16

uint16_t keys[ROWS][COLS];
uint16_t leds[ROWS][COLS];

uint8_t colPins[COLS] = { 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53 }; // Pins connected to R1, R2, R3, R4

CRGB led[NUM_LEDS];  
uint8_t hue = 0;


//-------------------------------------------------------------
void putLeds(){
  int pos = 0;
  for (int x=0; x < COLS; x++) {  
    for (int y=0; y < ROWS; y++) {  
      if(leds[x][y] == 1) {
        led[pos++] = CRGB::Red; 
      } else {
        led[pos++] = CRGB(238, 255, 0); 
      }
    } 
  }
  FastLED.show();
}

//------------------------------------------------------------
uint16_t getKey() {

  uint16_t k = -1;

  // Reset all
  for (uint8_t x=0; x < COLS; x++) {  digitalWrite(colPins[x], HIGH); }

  //Bit schreiben
  for (uint8_t x=0; x < COLS; x++) { 
    digitalWrite(colPins[x], LOW);  // Bit setzen

    //Bit lesen
    for (uint8_t y=0; y < ROWS; y++) { 
      uint16_t key = digitalRead(rowPins[y]);
      if (key == LOW) {
        k = keys[x][y];
        leds[x][y] = 1; 
      }
    }
    digitalWrite(colPins[x], HIGH);  // Bit rücksetzen 
  } 
  return k;
}



//----------------------------------------------------------------
void clearLeds() { 
   for (uint8_t x=0; x<COLS; x++) { 
    for (uint8_t y=0; y<ROWS; y++) {
       leds[x][y] = 0;
    }
  }
}


void rainbow() {
  for (int i = 0; i < NUM_LEDS; ++i) {
    led[i] = CHSV(hue + (i * 10), 255, 255);
  }
  //You can change the pattern speed here
  EVERY_N_MILLISECONDS(15){
    hue++;
  }
  FastLED.show();
}


//----------------------------------------------------------------
void setup() {
  Serial.begin(9600);

  FastLED.addLeds<WS2812B, DATA_PIN, GRB>(led, NUM_LEDS);
  FastLED.setBrightness(MAX_BRIGHTNESS);
  
  // Init Array
  // 0 1 2 3 
  // 7 6 5 4
  // 8 9
 
  /*
  boolean sw = true;
  int value = 0;
  for (uint8_t x=0; x<COLS; x++) { 
    for (uint8_t y=0; y<ROWS; y++) { 
      if(sw == true) {
        sw = !sw;
        keys[x][y] = value++;
      } else {
        sw = !sw;
        keys[x][y] = pos;

      }
    }
  }
  */

  for (uint8_t i=0; i<COLS; i++) { pinMode(colPins[i] , OUTPUT); }
  for (uint8_t i=0; i<ROWS; i++) { pinMode(rowPins[i] , INPUT_PULLUP); }
  
  
  clearLeds();
}



void loop() {

  uint16_t key;
  key = getKey();
  if (key != -1) { 
    Serial.println(key); 

  }
  rainbow();
  //putLeds();
  delay(200);
  
}