#include <Arduino.h>
#include <U8g2lib.h>
#include <Wire.h>
 
#define RotaryEncoderA 16
#define RotaryEncoderB 17
#define mosfetA 2
#define buttonA 18
#define pinHall 26
 
int counter = 0; 
int aState;
int aLastState;  
int buttonState = 0;
int lengthx = 1;
 
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);
 
void setup() {
  u8g2.begin();
  pinMode(RotaryEncoderA, INPUT);
  pinMode(RotaryEncoderB, INPUT);
  pinMode(buttonA, INPUT_PULLUP);
  pinMode(pinHall, INPUT);
  Serial.begin(9600);
  aLastState = digitalRead(RotaryEncoderA);
  u8g2.setFont(u8g2_font_logisoso32_tr);// choose a suitable font
}
 
void loop() { // INPUT HANDLER
 
  //ROTARY ENCODER
  aState = digitalRead(RotaryEncoderA);
  if (aState != aLastState) {
    if (digitalRead(RotaryEncoderB) != aState) { 
      counter ++;
    } else {
      counter --;
    }
    Serial.print("Position: ");
    Serial.println(counter);
  } else { delay(100); }
  aLastState = aState;
 
  //ROTARY ENCODER BUTTON
  if (buttonState != digitalRead(buttonA)) {
    buttonState = digitalRead(buttonA);
  }

  loop1();
}
void setup1() {
}
void loop1() { // RENDERER
 
  int dataout = analogRead(pinHall) * 0.001 * counter;
  u8g2.clearBuffer();
  char buf[8];
  itoa(counter, buf, 10);
  u8g2.drawStr(0, 32, buf);
  u8g2.drawBox(0, 32, counter, 32);
  u8g2.sendBuffer();
 
  if((counter > 0 ) && (counter < 255)) {
    analogWrite(mosfetA, counter);
  }
}