#include <LiquidCrystal_I2C.h>    

LiquidCrystal_I2C lcd(0x27,16,2);  

int led1 = 8;
int led2 = 9;
int led3 = 10;
int led4 = 11;
int led5 = 12

byte gauge_empty[8] =  {B11111, B00000, B00000, B00000, B00000, B00000, B00000, B11111};    
byte gauge_fill_1[8] = {B11111, B10000, B10000, B10000, B10000, B10000, B10000, B11111};    
byte gauge_fill_2[8] = {B11111, B11000, B11000, B11000, B11000, B11000, B11000, B11111};    
byte gauge_fill_3[8] = {B11111, B11100, B11100, B11100, B11100, B11100, B11100, B11111};    
byte gauge_fill_4[8] = {B11111, B11110, B11110, B11110, B11110, B11110, B11110, B11111};    
byte gauge_fill_5[8] = {B11111, B11111, B11111, B11111, B11111, B11111, B11111, B11111};    
byte gauge_left[8] =   {B11111, B10000, B10000, B10000, B10000, B10000, B10000, B11111};    
byte gauge_right[8] =  {B11111, B00001, B00001, B00001, B00001, B00001, B00001, B11111};    

byte gauge_mask_left[8] = {B01111, B11111, B11111, B11111, B11111, B11111, B11111, B01111};  
byte gauge_mask_right[8] = {B11110, B11111, B11111, B11111, B11111, B11111, B11111, B11110}; 

byte warning_icon[8] = {B00100, B00100, B01110, B01010, B11011, B11111, B11011, B11111};     

byte gauge_left_dynamic[8];   
byte gauge_right_dynamic[8];  

int battery_gauge = 0;      
char buffer[100];        
int move_offset = 0;    

const int gauge_size_chars = 16;       // width of the gauge in number of characters
char gauge_string[gauge_size_chars+1]; // string that will include all the gauge character to be printed

void setup()
{
  lcd.init();                      
  lcd.createChar(7, gauge_empty);  
  lcd.createChar(1, gauge_fill_1);  
  lcd.createChar(2, gauge_fill_2);  
  lcd.createChar(3, gauge_fill_3);  
  lcd.createChar(4, gauge_fill_4);  
  lcd.createChar(0, warning_icon); 
  lcd.backlight();                  
}


void loop()
{
  float units_per_pixel = (gauge_size_chars*5.0)/100.0;       
  int value_in_pixels = round(battery_gauge * units_per_pixel);    

  int tip_position = 0;     

  if (value_in_pixels < 5) {tip_position = 1;}                            
  else if (value_in_pixels > gauge_size_chars*5.0-5) {tip_position = 3;}  
  else {tip_position = 2;}                                                

  move_offset = 4 - ((value_in_pixels-1) % 5);

  for (int i=0; i<8; i++) {   
     if (tip_position == 1) {gauge_left_dynamic[i] = (gauge_fill_5[i] << move_offset) | gauge_left[i];}  
     else {gauge_left_dynamic[i] = gauge_fill_5[i];}                                                     
 
     gauge_left_dynamic[i] = gauge_left_dynamic[i] & gauge_mask_left[i];                                
  }

  for (int i=0; i<8; i++) {   // dynamically create right part of the gauge
     if (tip_position == 3) {gauge_right_dynamic[i] = (gauge_fill_5[i] << move_offset) | gauge_right[i];}  
     else {gauge_right_dynamic[i] = gauge_right[i];}                                                       

     gauge_right_dynamic[i] = gauge_right_dynamic[i] & gauge_mask_right[i];                              
  }  

  lcd.createChar(5, gauge_left_dynamic);    
  lcd.createChar(6, gauge_right_dynamic);    

  for (int i=0; i<gauge_size_chars; i++) {  
      if (i==0) {gauge_string[i] = byte(5);}                        
      else if (i==gauge_size_chars-1) {gauge_string[i] = byte(6);}  
      else {                                                        
         if (value_in_pixels <= i*5) {gauge_string[i] = byte(7);}  
         else if (value_in_pixels > i*5 && value_in_pixels < (i+1)*5) {gauge_string[i] = byte(5-move_offset);} 
         else {gauge_string[i] = byte(255);}                       
      }
  }

  
  lcd.setCursor(0,0);                         
  sprintf(buffer, "battery:%3d%% ", battery_gauge);    
  lcd.print(buffer);                         
  lcd.write(byte(0));                         
  
  lcd.setCursor(0,1);             
  lcd.print(gauge_string);         



  
  battery_gauge = battery_gauge +1;
  if (battery_gauge > 100) {battery_gauge = 0;}

  delay(1000);  
}