// Forum: https://forum.arduino.cc/t/counter-misfunctioning-with-oled-i2c-display/1009288

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

int inputCLK = 6;
int inputDT = 5;
int inputSW = 4;

int counter = 0;
int currentStateCLK;
int previousStateCLK;

//int SCLPin=A5;
//int SDAPin=A4;

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 oled (SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

void setup() {
  // put your setup code here, to run once:

  // Start serial
  Serial.begin(9600);


  // Start screen
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true);
  }

  //define pinModes
  pinMode(inputCLK, INPUT);
  pinMode(inputDT, INPUT);
  pinMode(inputSW, INPUT);

  //current state
  previousStateCLK = digitalRead(inputCLK);

  //delay setup
  delay(2000);

}

void loop() {
  // put your main code here, to run repeatedly:
  currentStateCLK = digitalRead(inputCLK);

  if (currentStateCLK != previousStateCLK) {
    //se se mexeu CCW
    if (digitalRead(inputDT) != currentStateCLK) {
      counter = counter + 1;
      if (counter > 3) {
        counter = 3;
      }
    }
    // se se mexeu CW
    if (digitalRead(inputDT) == currentStateCLK) {
      counter = counter - 1;
      if (counter < 0) {
        counter = 0;
      }
    }
  }

  Serial.println(counter);

  if (counter == 0) {
    oled.clearDisplay();
    oled.setCursor(0, 0);
    oled.setTextColor(WHITE);
    oled.setTextSize(2);
    oled.println("Temp");
    oled.println("Humidade");
    oled.println("Luz");
    oled.display();
    previousStateCLK = currentStateCLK;
  }

  if (counter == 1) {
    oled.clearDisplay();
    oled.setCursor(0, 0);
    oled.setTextColor(WHITE);
    oled.setTextSize(2);
    oled.println(">Temp");
    oled.println("Humidade");
    oled.println("Luz");
    oled.display();
    previousStateCLK = currentStateCLK;
  }

  if (counter == 2) {
    oled.clearDisplay();
    oled.setCursor(0, 0);
    oled.setTextColor(WHITE);
    oled.setTextSize(2);
    oled.println("Temp");
    oled.println(">Humidade");
    oled.println("Luz");
    oled.display();
    previousStateCLK = currentStateCLK;
  }

  if (counter == 3) {
    oled.clearDisplay();
    oled.setCursor(0, 0);
    oled.setTextColor(WHITE);
    oled.setTextSize(2);
    oled.println("Temp");
    oled.println("Humidade");
    oled.println(">Luz");
    oled.display();
    previousStateCLK = currentStateCLK;
  }

  previousStateCLK = currentStateCLK;
}