#include "U8glib.h"

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST); // Fast I2C / TWI

#define BUTTON_LEFT_PIN 4 //pin for left button
#define BUTTON_ENTER_PIN 8 //pin for enter button
#define BUTTON_RIGHT_PIN 12 //pin for right button

int item_sel = 0; //which item is selected
int item_sel_previous = 0; //which item is previous
int item_sel_next = 0; // which item is next

int current_screen = 1; // 0=start menu 1=breaker rating, 2=breaker type , 3=cable size, 4=BR, 5=BT, 6=CS

int button_left_clicked = 0; // only perform action when button is clicked, and wait until another press
int button_enter_clicked = 0; // same as above
int button_right_clicked = 0; // same as above


const int analogPin = A0;
//int raw = 0;
//int Vin = 5;
//float Vout = 0;
//float R1 = 30;
//float R2 = 0;
//float buffer = 0;

// ' scrollbar_background', 128x8px
const unsigned char epd_bitmap__scrollbar_background [] PROGMEM = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x54,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
// 'arrow_right', 16x16px
const unsigned char epd_bitmap_arrow_right [] PROGMEM = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0x00, 0x70, 0xff, 0xf8, 0xff, 0xfc, 0xff, 0xfe, 0xff, 0xff,
  0xff, 0xff, 0xff, 0xfe, 0xff, 0xfc, 0xff, 0xf8, 0x00, 0x70, 0x00, 0x60, 0x00, 0x00, 0x00, 0x00
};
// 'arrow_left', 16x16px
const unsigned char epd_bitmap_arrow_left [] PROGMEM = {
  0x00, 0x00, 0x00, 0x00, 0x06, 0x00, 0x0e, 0x00, 0x1f, 0xff, 0x3f, 0xff, 0x7f, 0xff, 0xff, 0xff,
  0xff, 0xff, 0x7f, 0xff, 0x3f, 0xff, 0x1f, 0xff, 0x0e, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00
};

// ' border', 128x21px
const unsigned char epd_bitmap__border [] PROGMEM = {
  0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8,
  0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03,
  0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06,
  0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfc,
  0x0f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8
};

// ' breaker_rating_icon', 16x16px
const unsigned char epd_bitmap__breaker_rating_icon [] PROGMEM = {
  0x00, 0x00, 0x0f, 0xf0, 0x0f, 0xf0, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c,
  0x3c, 0x3c, 0x3f, 0xfc, 0x3f, 0xfc, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x00, 0x00
};
// ' breaker_type_icon', 16x16px
const unsigned char epd_bitmap__breaker_type_icon [] PROGMEM = {
  0x0f, 0xf0, 0x08, 0x10, 0x09, 0x90, 0x08, 0x10, 0x08, 0x10, 0x08, 0x10, 0x0b, 0xd0, 0x09, 0x90,
  0x09, 0x90, 0x08, 0x10, 0x08, 0x10, 0x08, 0x10, 0x08, 0x10, 0x09, 0x90, 0x08, 0x10, 0x0f, 0xf0
};
// ' cable_size_icon', 16x16px
const unsigned char epd_bitmap__cable_size_icon [] PROGMEM = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x10, 0x02, 0x10, 0x31, 0x20, 0x09, 0x40,
  0x05, 0x40, 0x05, 0x40, 0x05, 0x40, 0x0a, 0xa0, 0x08, 0xa0, 0x08, 0xa0, 0x0a, 0xa0, 0x0a, 0xa0
};

// Array of all bitmaps for convenience. (Total bytes used to store images in PROGMEM = 192)
const unsigned char* bitmap_icons[3] = {
  epd_bitmap__breaker_rating_icon,
  epd_bitmap__breaker_type_icon,
  epd_bitmap__cable_size_icon,
};
const int NUM_ITEMS = 3;
char menu_items [NUM_ITEMS] [15] = {
  {"Breaker Rating"},
  {"Breaker Type  "},
  {"Cable Size    "}
};

const int NUM_RATING = 9;
char Breaker_items [NUM_RATING] [4] = {
  {"6A "},
  {"10A"},
  {"16A"},
  {"20A"},
  {"25A"},
  {"32A"},
  {"40A"},
  {"50A"},
  {"63A"}
};
const int NUM_TYPE = 3;
char Breaker_type [NUM_TYPE] [7] = {
  {"Type B"},
  {"Type C"},
  {"Type D"}
};


const int CS_10 = 2;
char Cable_sz_1 [CS_10] [6] = {
  "1.0mm",
  "1.5mm"
};

const int CS_16 = 2;
char Cable_sz_2 [CS_16] [6] = {
  "1.5mm",
  "2.5mm"
};

const int CS = 6;
char Cable_sz_0 [CS] [6] = {
  "1.0mm",
  "2.5mm",
  "4.0mm",
  "6.0mm",
  "10mm ",
  "16mm "
};

bool B_Type [3] = {false, false, false};
byte btype = 0;

bool B_Rating [9]  = {false, false, false, false, false, false, false, false, false};
byte brating = 0;
byte brating1 = 0;

bool C_Size [7] = {false, false, false, false, false, false, false};
byte csize = 0;

const int BREAKER_TYPES = 3;
const int BREAKER_RATINGS = 9;
int breakerRating = 0;
int breakerType = 0;
const float resistanceTable[BREAKER_RATINGS][BREAKER_TYPES] = {
  //6A
  {
    6.1, 3.3, 2.0 // Type B, C, D - 1mm
  },
  //10A
  {
    3.7, 2.0, 1.2 // Type B, C, D - 1mm & 1.5mm
  },
  //16A
  {
    2.3, 1.2, 0.7 // Type B, C, D - 1.5mm & 2.5mm
  },
  //20A
  {
    1.8, 1.0, 0.6 // Type B, C, D - 2.5mm
  },
  //25A
  {
    1.5, 0.8, 0.5 // Type B, C, D - 4mm
  },
  //32A
  {
    1.2, 0.6, 0.4 // Type B, C, D - 4mm
  },
  //40A
  {
    0.9, 0.5, 0.3 // Type B, C, D - 6mm
  },
  //50A
  {
    0.7, 0.4, 0.2 // Type B, C, D - 10mm    
  },
  //63A
  {
    0.6, 0.3, 0.2 // Type B, C, D - 16mm
  }
};

const int CONFIRM = 2;
char Confirm [CONFIRM] [17] = {
  {"Enter to Confirm"},
  {" Left to Cancel "}
};

void setup() {

  pinMode(BUTTON_LEFT_PIN, INPUT_PULLUP);
  pinMode(BUTTON_ENTER_PIN, INPUT_PULLUP);
  pinMode(BUTTON_RIGHT_PIN, INPUT_PULLUP);

  u8g.setFont(u8g_font_tpssb);
  u8g.setColorIndex(1);

}

void loop() {

  float resistanceValue = resistanceTable[breakerRating][breakerType];

  int sensorValue = analogRead(analogPin);

  // Assuming a 5V reference voltage
  float voltage = sensorValue * (5.0 / 1024.0);

  // Calculate the resistance using the voltage divider formula
  // R1 = R2 * (Vin / Vout - 1)
  const int knownResistance = 20;  // Replace with the resistance value of R2 in ohms
  float unknownResistance = knownResistance * (5.0 / voltage);

  //raw = analogRead(analogPin);
  //if (raw) {
  //  buffer = raw * Vin;
  //  Vout = (buffer) / 1024.0;
  //  buffer = (Vin / Vout) - 1;
  //  R2 = R1 * buffer;
  //}
  u8g.firstPage();
  do {
    
    for (int i = 0; i < 3; i++) { //Breaker type

      btype |= (B_Type[i] << (2 - i));
    }
    for (int b = 0; b < 8; b++) { //Breaker rating

      brating |= (B_Rating[b] << (7 - b));
    }
    brating1 = B_Rating[8] << 7;
    for (int c =  0; c < 7; c++) { //Cable Size
      csize |= (C_Size[c] << (6 - c));
    }

    if (current_screen == 1) { // breaker rating
      //left arrow
      u8g.drawBitmapP((64 - u8g.getStrWidth(Breaker_items[item_sel]) / 2) - 21, 30, 16 / 8, 16, epd_bitmap_arrow_left);
      //right arrow
      u8g.drawBitmapP((64 + u8g.getStrWidth(Breaker_items[item_sel]) / 2) + 5, 30, 16 / 8, 16, epd_bitmap_arrow_right);
      //breaker rating icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[0]);
      u8g.drawStr(22, 15, menu_items[0]);
      // selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Breaker_items[item_sel]) / 2, 42, Breaker_items[item_sel]);
      //scrollbar
      u8g.drawBitmapP(1, 56, 128 / 8, 8, epd_bitmap__scrollbar_background);
      u8g.drawBox(128 / NUM_RATING * item_sel, 59, 128 / NUM_RATING, 3);

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {//UP button is pressed
        item_sel = item_sel - 1;
        button_left_clicked = 1;
        if (item_sel < 0) {
          item_sel = NUM_RATING - 1;
        }
      }

      if ((digitalRead(BUTTON_RIGHT_PIN) == LOW) && (button_right_clicked == 0)) {//DOWN button is pressed
        item_sel = item_sel + 1;
        button_right_clicked = 1;
        if (item_sel >= NUM_RATING) {
          item_sel = 0;
        }
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        current_screen = 2;
      }


      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) { // unclick

        button_left_clicked = 0;
      }
      if ((digitalRead(BUTTON_RIGHT_PIN) == HIGH) && (button_right_clicked == 1)) { // unclick
        button_right_clicked = 0;
      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }

      item_sel_previous = item_sel - 1;
      if (item_sel_previous < 0) {
        item_sel_previous = NUM_RATING - 1;
      }
      item_sel_next = item_sel + 1;
      if (item_sel_next >= NUM_RATING) {
        item_sel_next = 0;
      }

    }
    else if (current_screen == 2) {//Breaker Rating selection screen
      u8g.setColorIndex(1);
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Breaker_items[item_sel]) / 2, 42, Breaker_items[item_sel]);
      u8g.setFont(u8g_font_5x8);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 7, Confirm[0]);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 63, Confirm[1]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        if (Breaker_items[item_sel] == Breaker_items [0]) {
          current_screen = 5; //6A
          B_Rating[0] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[1]) {
          current_screen = 6; //10A
          //ten = true;
          B_Rating[1] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[2]) {
          current_screen = 7; //16A
          B_Rating[2] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[3]) {
          current_screen = 8; //20A
          B_Rating[3] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[4]) {
          current_screen = 9; //25A
          B_Rating[4] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[5]) {
          current_screen = 13; //32A
          B_Rating[5] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[6]) {
          current_screen = 10; //40A
          B_Rating[6] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[7]) {
          current_screen = 11; //50A
          B_Rating[7] = true;
        }
        else if (Breaker_items[item_sel] == Breaker_items[8]) {
          current_screen = 12; //63A
          B_Rating[8] = true;
        }

      }

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {
        current_screen --;

      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) {
        button_left_clicked = 0;
      }
    }


    else if (current_screen == 3) {//breaker type

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {//UP button is pressed
        item_sel = item_sel - 1;
        button_left_clicked = 1;
        if (item_sel < 0) {
          item_sel = NUM_TYPE - 1;
        }
      }

      if ((digitalRead(BUTTON_RIGHT_PIN) == LOW) && (button_right_clicked == 0)) {//DOWN button is pressed
        item_sel = item_sel + 1;
        button_right_clicked = 1;
        if (item_sel >= NUM_TYPE) {
          item_sel = 0;
        }
      }
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0 )) {

        button_enter_clicked = 1;
        current_screen ++;
      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }

      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) { // unclick
        button_left_clicked = 0;
      }
      if ((digitalRead(BUTTON_RIGHT_PIN) == HIGH) && (button_right_clicked == 1)) { // unclick
        button_right_clicked = 0;
      }

      //left arrow
      u8g.drawBitmapP((64 - u8g.getStrWidth(Breaker_type[item_sel]) / 2) - 21, 30, 16 / 8, 16, epd_bitmap_arrow_left);
      //right arrow
      u8g.drawBitmapP((64 + u8g.getStrWidth(Breaker_type[item_sel]) / 2) + 5, 30, 16 / 8, 16, epd_bitmap_arrow_right);
      //breaker rating icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[1]);
      u8g.drawStr(22, 15, menu_items[1]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Breaker_type[item_sel]) / 2, 42, Breaker_type[item_sel]);
      //scrollbar
      u8g.drawBitmapP(1, 56, 128 / 8, 8, epd_bitmap__scrollbar_background);
      u8g.drawBox(128 / NUM_TYPE * item_sel, 59, 128 / NUM_TYPE, 3);

    }
    else if (current_screen == 4) {//Breaker type selection screen
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Breaker_type[item_sel]) / 2, 42, Breaker_type[item_sel]);
      u8g.setFont(u8g_font_5x8);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 7, Confirm[0]);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 63, Confirm[1]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        current_screen = 17;
        if (Breaker_type[item_sel] == Breaker_type[0]) {
          B_Type[0] = true;
        }
        else if (Breaker_type[item_sel] == Breaker_type[1]) {
          B_Type[1] = true;
        }
        else if (Breaker_type[item_sel] == Breaker_type[2]) {
          B_Type[2] = true;
        }
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {
        current_screen --;
        item_sel = 1;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;

      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) {
        button_left_clicked = 0;
      }

    }

    else if (current_screen == 5) {//cable size 6A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.getStrWidth(Cable_sz_0[0]);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0[0]) / 2, 42, Cable_sz_0[0]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }

    else if (current_screen == 6) {//cable size 10A

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {//UP button is pressed
        item_sel = item_sel - 1;
        button_left_clicked = 1;
        if (item_sel < 0) {
          item_sel = CS_10 - 1;
        }
      }

      if ((digitalRead(BUTTON_RIGHT_PIN) == LOW) && (button_right_clicked == 0)) {//DOWN button is pressed
        item_sel = item_sel + 1;
        button_right_clicked = 1;
        if (item_sel >= CS_10) {
          item_sel = 0;
        }
      }
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 14;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) { // unclick
        button_left_clicked = 0;
      }
      if ((digitalRead(BUTTON_RIGHT_PIN) == HIGH) && (button_right_clicked == 1)) { // unclick
        button_right_clicked = 0;
      }
      item_sel_previous = item_sel - 1;
      if (item_sel_previous < 0) {
        item_sel_previous = CS_10 - 1;
      }
      item_sel_next = item_sel + 1;
      if (item_sel_next >= CS_10) {
        item_sel_next = 0;
      }

      //left arrow
      u8g.drawBitmapP((64 - u8g.getStrWidth(Cable_sz_1[item_sel]) / 2) - 21, 30, 16 / 8, 16, epd_bitmap_arrow_left);
      //right arrow
      u8g.drawBitmapP((64 + u8g.getStrWidth(Cable_sz_1[item_sel]) / 2) + 5, 30, 16 / 8, 16, epd_bitmap_arrow_right);
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.getStrWidth(Cable_sz_1[item_sel]);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_1[item_sel]) / 2, 42, Cable_sz_1[item_sel]);
      //scrollbar
      u8g.drawBitmapP(1, 56, 128 / 8, 8, epd_bitmap__scrollbar_background);
      u8g.drawBox(128 / CS_10 * item_sel, 59, 128 / CS_10, 3);
    }

    else if (current_screen == 7) {//cable size 16A

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {//UP button is pressed
        item_sel = item_sel - 1;
        button_left_clicked = 1;
        if (item_sel < 0) {
          item_sel = CS_16 - 1;
        }
      }

      if ((digitalRead(BUTTON_RIGHT_PIN) == LOW) && (button_right_clicked == 0)) {//DOWN button is pressed
        item_sel = item_sel + 1;
        button_right_clicked = 1;
        if (item_sel >= CS_16) {
          item_sel = 0;
        }
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 15;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) { // unclick
        button_left_clicked = 0;
      }
      if ((digitalRead(BUTTON_RIGHT_PIN) == HIGH) && (button_right_clicked == 1)) { // unclick
        button_right_clicked = 0;
      }

      //left arrow
      u8g.drawBitmapP((64 - u8g.getStrWidth(Cable_sz_2[item_sel]) / 2) - 21, 30, 16 / 8, 16, epd_bitmap_arrow_left);
      //right arrow
      u8g.drawBitmapP((64 + u8g.getStrWidth(Cable_sz_2[item_sel]) / 2) + 5, 30, 16 / 8, 16, epd_bitmap_arrow_right);
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.getStrWidth(Cable_sz_2[item_sel]);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_2[item_sel]) / 2, 42, Cable_sz_2[item_sel]);
      //scrollbar
      u8g.drawBitmapP(1, 56, 128 / 8, 8, epd_bitmap__scrollbar_background);
      u8g.drawBox(128 / CS_16 * item_sel, 59, 128 / CS_16, 3);
    }
    else if (current_screen == 8) {//cable size 20A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0[1]) / 2, 42, Cable_sz_0[1]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 9) {//cable size 25A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0[2]) / 2, 42, Cable_sz_0[2]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 10) {//cable size 40A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0[3]) / 2, 42, Cable_sz_0[3]);
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 11) {//cable size 50A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0[4]) / 2, 42, Cable_sz_0[4]);
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 12) {//cable size 63A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0 [5]) / 2, 42, Cable_sz_0 [5]);
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 13) {//cable size 32A
      //cable size icon & text
      u8g.drawBitmapP(3, 2, 16 / 8, 16, bitmap_icons[2]);
      u8g.drawStr(22, 15, menu_items[2]);
      //selected item
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0 [2]) / 2, 42, Cable_sz_0 [2]);
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) {
        button_enter_clicked = 1;
        current_screen = 16;
      }

      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) {
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 14) {//Cable size selection screen 10A
      u8g.setColorIndex(1);
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_1[item_sel]) / 2, 42, Cable_sz_1[item_sel]);
      u8g.setFont(u8g_font_5x8);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 7, Confirm[0]);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 63, Confirm[1]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        current_screen = 3;
        if (Cable_sz_1[item_sel] == Cable_sz_1[0]) {
          C_Size[0] = true;
        }
        else if (Cable_sz_1[item_sel] == Cable_sz_1[1]) {
          C_Size[1] = true;
        }
      }

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {
        current_screen --;

      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) {
        button_left_clicked = 0;
      }
    }

    else if (current_screen == 15) {//Cable size selection screen 16A
      u8g.setColorIndex(1);
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_2[item_sel]) / 2, 42, Cable_sz_2[item_sel]);
      u8g.setFont(u8g_font_5x8);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 7, Confirm[0]);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 63, Confirm[1]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        current_screen = 3;
        if (Cable_sz_2[item_sel] == Cable_sz_2[0]) {
          C_Size[0] = true;
        }
        else if (Cable_sz_1[item_sel] == Cable_sz_1[1]) {
          C_Size[2] = true;
        }
      }

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {
        current_screen --;

      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) {
        button_left_clicked = 0;
      }
    }

    else if (current_screen == 16) {//Cable size selection screen (6A,20A,25A,32A,50A,63A)
      u8g.setColorIndex(1);
      u8g.setFont(u8g_font_7x14B);
      u8g.drawStr(64 - u8g.getStrWidth(Cable_sz_0[item_sel]) / 2, 42, Cable_sz_0[item_sel]);
      u8g.setFont(u8g_font_5x8);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 7, Confirm[0]);
      u8g.drawStr(64 - u8g.getStrWidth(Confirm[CONFIRM]) / 2, 63, Confirm[1]);

      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        current_screen = 3;
        if (Cable_sz_0[item_sel] == Cable_sz_0[0]) {
          C_Size[0] = true;
        }
        else if (Cable_sz_0[item_sel] == Cable_sz_0[1]) {
          C_Size[2] = true;
        }
        else if (Cable_sz_0[item_sel] == Cable_sz_0[2]) {
          C_Size[3] = true;
        }
        else if (Cable_sz_0[item_sel] == Cable_sz_0[3]) {
          C_Size[4] = true;
        }
        else if (Cable_sz_0[item_sel] == Cable_sz_0[4]) {
          C_Size[5] = true;
        }
        else if (Cable_sz_0[item_sel] == Cable_sz_0[5]) {
          C_Size[6] = true;
        }
      }

      if ((digitalRead(BUTTON_LEFT_PIN) == LOW) && (button_left_clicked == 0)) {
        current_screen --;

      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }
      if ((digitalRead(BUTTON_LEFT_PIN) == HIGH) && (button_left_clicked == 1)) {
        button_left_clicked = 0;
      }
    }
    else if (current_screen == 17) {//final confirmation screen
      switch (btype) {
        case 0b100: //Btype
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_type[0]) / 2, 15, Breaker_type[0]);
          breakerType = 0;
          break;
        case 0b010: //Ctype
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_type[1]) / 2, 15, Breaker_type[1]);
          breakerType = 1;
          break;
        case 0b001: //Dtype
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_type[2]) / 2, 15, Breaker_type[2]);
          breakerType = 2;
      }
      switch (brating) {
        case 0b10000000: //6A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[0]) / 2, 42, Breaker_items[0]);
          breakerRating = 0;
          break;
        case 0b01000000: //10A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[1]) / 2, 42, Breaker_items[1]);
          breakerRating = 1;
          break;
        case 0b00100000: //16A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[2]) / 2, 42, Breaker_items[2]);
          breakerRating = 2;
          break;
        case 0b00010000: //20A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[3]) / 2, 42, Breaker_items[3]);
          breakerRating = 3;
          break;
        case 0b00001000: //25A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[4]) / 2, 42, Breaker_items[4]);
          breakerRating = 4;
          break;
        case 0b00000100: //32A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[5]) / 2, 42, Breaker_items[5]);
          breakerRating = 5;
          break;
        case 0b00000010: //40A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[6]) / 2, 42, Breaker_items[6]);
          breakerRating = 6;
          break;
        case 0b00000001: //50A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[7]) / 2, 42, Breaker_items[7]);
          breakerRating = 7;
          break;
      }
      switch (brating1) {
        case 0b10000000: //63A
          u8g.setFont(u8g_font_7x14);
          u8g.drawStr(32 - u8g.getStrWidth(Breaker_items[8]) / 2, 42, Breaker_items[8]);
          breakerRating = 8;
          break;
      }
      switch (csize) {
        case 0b1000000: //1mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_0[0]) / 2, 64, Cable_sz_0[0]);
          break;
        case 0b0100000: //1.5mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_1[1]) / 2, 64, Cable_sz_1[1]);
          break;
        case 0b0010000: //2.5mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_0[1]) / 2, 64, Cable_sz_0[1]);
          break;
        case 0b0001000: //4mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_0[2]) / 2, 64, Cable_sz_0[2]);
          break;
        case 0b0000100: //6mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_0[3]) / 2, 64, Cable_sz_0[3]);
          break;
        case 0b0000010: //10mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_0[4]) / 2, 64, Cable_sz_0[4]);
          break;
        case 0b0000001: //16mm
          u8g.setFont(u8g_font_7x14B);
          u8g.drawStr(32 - u8g.getStrWidth(Cable_sz_0[5]) / 2, 64, Cable_sz_0[5]);
          break;
      }
      u8g.setFont(u8g_font_7x14B);
      u8g.setPrintPos(64, 42);
      u8g.print("Confirm?");
      if ((digitalRead(BUTTON_ENTER_PIN) == LOW) && (button_enter_clicked == 0)) { //ENTER button is pressed
        button_enter_clicked = 1;
        current_screen = 18;
      }
      if ((digitalRead(BUTTON_ENTER_PIN) == HIGH) && (button_enter_clicked == 1)) { // unclick
        button_enter_clicked = 0;
      }
    }
    else if (current_screen == 18) {// resistance test

      u8g.setPrintPos(64, 32);
      u8g.print(unknownResistance);
      u8g.setPrintPos(64, 52);
      u8g.print(resistanceValue);
      if (unknownResistance > resistanceValue) {
        u8g.setPrintPos(64,64);
        u8g.print("FAIL");
      }
      else if (unknownResistance <= resistanceValue){
        u8g.setPrintPos(64,64);
        u8g.print("PASS");
      }
      else {
        u8g.setPrintPos(64,64);
        u8g.print("no resistance read");        
      }
    }
  } while  (u8g.nextPage());
}