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

#define outputA 2  //CLK pin
#define outputB 3  //DT pin
#define rstbtn  4  //reset button pin
 
int counter = 0;
const float pi = 3.14; // Pi value 
 
const int R = 7;  //Radius of the wheel from center to edge
const int N = 40; //no of steps for one rotation
float distance = 0;
 


#define SCREEN_WIDTH 128 // OLED display width,  in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// declare an SSD1306 display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

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

  // initialize OLED display with address 0x3C for 128x64
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true);
  }

  delay(2000);         // wait for initializing
  oled.clearDisplay(); // clear display

  oled.setTextSize(1);          // text size
  oled.setTextColor(WHITE);     // text color
  oled.setCursor(0, 10);        // position to display
  oled.println ("ricci culo"); // text to display
  oled.display();               // show on OLED
  


  // Initialize encoder pins
  pinMode(outputA, INPUT);
  pinMode(outputB, INPUT);
  pinMode(rstbtn, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(outputA), readEncoder, FALLING);
  
  delay(2000);
  oled.clearDisplay(); // clear display
}


void readEncoder() {
  int bValue = digitalRead(outputB);
  if (bValue == HIGH) {
    counter++; // Clockwise
  }
  if (bValue == LOW) {
    counter--; // Counterclockwise
  }
}
 
// Get the counter value, disabling interrupts.
// This make sure readEncoder() doesn't change the value
// while we're reading it.
int getCounter() {
  int result;
  noInterrupts();
  result = counter;
  interrupts();
  return result;
}
 
void resetCounter() {
  noInterrupts();
  counter = 0;
  interrupts();
}
 





void loop() {
 
   oled.clearDisplay(); // clear display
  distance = ((2*pi*R)/N) * getCounter();
   oled.setCursor(0, 0);        // position to display
  oled.println("Distanza: in cm");
  oled.setCursor(0, 10);
  oled.println(distance);
  oled.println("        ");
  oled.display();               // show on OLED
 
  if (digitalRead(rstbtn) == LOW) {
    resetCounter();
}
}