// Robust Rotary encoder reading // // Copyright John Main - best-microcontroller-projects.com
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Encoder.h>

#define SCREEN_WIDTH 128  // OLED display width, in pixels
#define SCREEN_HEIGHT 64  // OLED display height, in pixels
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

#define CLK 2
#define DATA 3
Encoder encoder(DATA, CLK);
int lastEncoderValue = 0;
int state=0;
int test=0;

int readDelta() {
  //int value = encoder.read();
  int value = encoder.read() / 4;
  int delta = value - lastEncoderValue;
  lastEncoderValue = value;
  return delta;
}

#define MENU_LENGTH 5
int constrainMenu(int value) {
  return value - MENU_LENGTH * floor((float) value / MENU_LENGTH);
}

void setup() {
  //pinMode(CLK, INPUT);
  //pinMode(CLK, INPUT_PULLUP);
  //pinMode(DATA, INPUT);
  //pinMode(DATA, INPUT_PULLUP);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.display();
  delay(500);  // Pause for 4 seconds
  Serial.begin(115200);
  Serial.println("KY-040 Start:");
  

}

static uint8_t prevNextCode = 0;
static uint16_t store = 0;
void loop() {
  display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(5, 12);
    display.println(F("Encoder Value:"));
  test+=readDelta();
  //test=constrainMenu(test+readDelta()); //test menu rotativo
  if(test!=state){
    Serial.println(test);
    state=test;
  }
  display.setTextSize(2);
    display.setTextColor(WHITE);
    display.setCursor(90, 8);
    display.println(test);
    display.display();


  /*
  static int8_t c, val;
   display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(WHITE);
    display.setCursor(5, 12);
    display.println(F("Encoder Value:"));
    //display.display();
  if (val = read_rotary()) {
    c += val;
    Serial.print(c);
    display.setTextSize(2);
    display.setTextColor(WHITE);
    display.setCursor(90, 8);
    display.println(c);
    display.display();
    Serial.print(" ");
    if (prevNextCode == 0x0b) {
      Serial.print("eleven ");
      Serial.println(store, HEX);
    }
    if (prevNextCode == 0x07) {
      Serial.print("seven ");
      Serial.println(store, HEX);
    }
  }*/
  
}
// A vald CW or CCW move returns 1, invalid returns 0.
int8_t read_rotary() {
  static int8_t rot_enc_table[] = { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };
  prevNextCode <<= 2;
  if (digitalRead(DATA)) prevNextCode |= 0x02;
  if (digitalRead(CLK)) prevNextCode |= 0x01;
  prevNextCode &= 0x0f;  // If valid then store as 16 bit data.
  if (rot_enc_table[prevNextCode]) {
    store <<= 4;
    store |= prevNextCode;  
    //if (store==0xd42b) return 1; 
    //if (store==0xe817) return -1;
    if ((store & 0xff) == 0x2b) return -1;
    if ((store & 0xff) == 0x17) return 1;
  }
  return 0;
}