// simple project using Arduino UNO and 16x2 character display to display smooth gauge, 
// created by upir, 2022
// modified by herma, 02/2024 legge potenziometro

// youtube channel: https://www.youtube.com/upir_upir
// FULL TUTORIAL: https://youtu.be/ZzIGHiHObYw 
// GAUGE IN 11 MINUTES TUTORIAL: https://youtu.be/upE17NHrdPc

// Links
// character creator - https://maxpromer.github.io/LCD-Character-Creator/
// sprintf explanation - https://www.programmingelectronics.com/sprintf-arduino/
// custom characters simplest project - https://wokwi.com/projects/294395602645549578
// Arduino I2C scanner - https://playground.arduino.cc/Main/I2cScanner/
// 16x2 available characters - https://docs.wokwi.com/parts/wokwi-lcd1602#font



#include <LiquidCrystal_I2C.h> 
#include "H_BarGraph.h"

LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display
//LiquidCrystal_I2C lcd(0x3f,16,2);    // set the LCD address to 0x3f for a 16 chars and 2 line display

int val_trimmer=0;


void setup()
{ lcdSetup();

}


void loop()
{
  
  val_gauge = map(analogRead(A0), 0, 1023, 0, 100);
  
  drawGraph();

  delay(500);  // wait for a while 
}

void lcdSetup(void) {
  lcd.init();                       // initialize the 16x2 lcd module
  lcd.createChar(7, gauge_empty);   // middle empty gauge
  lcd.createChar(1, gauge_fill_1);  // filled gauge - 1 column
  lcd.createChar(2, gauge_fill_2);  // filled gauge - 2 columns
  lcd.createChar(3, gauge_fill_3);  // filled gauge - 3 columns
  lcd.createChar(4, gauge_fill_4);  // filled gauge - 4 columns  
  lcd.createChar(0, warning_icon); // warning icon - just because we have one more custom character that we could use  
  lcd.backlight();                  // enable backlight for the LCD module
}

void drawGraph (void) {
  float units_per_pixel = (gauge_size_chars*5.0)/100.0;        //  every character is 5px wide, we want to count from 0-100
  int value_in_pixels = round(val_gauge * units_per_pixel);    // cpu_gauge value converted to pixel width

  int tip_position = 0;      // 0= not set, 1=tip in first char, 2=tip in middle, 3=tip in last char

  if (value_in_pixels < 5) {tip_position = 1;}                            // tip is inside the first character
  else if (value_in_pixels > gauge_size_chars*5.0-5) {tip_position = 3;}  // tip is inside the last character
  else {tip_position = 2;}                                                // tip is somewhere in the middle

  move_offset = 4 - ((value_in_pixels-1) % 5);      // value for offseting the pixels for the smooth filling

  for (int i=0; i<8; i++) {   // dynamically create left part of the gauge
     if (tip_position == 1) {gauge_left_dynamic[i] = (gauge_fill_5[i] << move_offset) | gauge_left[i];}  // tip on the first character
     else {gauge_left_dynamic[i] = gauge_fill_5[i];}                                                     // tip not on the first character
 
     gauge_left_dynamic[i] = gauge_left_dynamic[i] & gauge_mask_left[i];                                 // apply mask for rounded corners
  }

  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];}  // tip on the last character
     else {gauge_right_dynamic[i] = gauge_right[i];}                                                       // tip not on the last character

     gauge_right_dynamic[i] = gauge_right_dynamic[i] & gauge_mask_right[i];                                // apply mask for rounded corners
  }  

  lcd.createChar(5, gauge_left_dynamic);     // create custom character for the left part of the gauge
  lcd.createChar(6, gauge_right_dynamic);    // create custom character for the right part of the gauge

  for (int i=0; i<gauge_size_chars; i++) {  // set all the characters for the gauge
      if (i==0) {gauge_string[i] = byte(5);}                        // first character = custom left piece
      else if (i==gauge_size_chars-1) {gauge_string[i] = byte(6);}  // last character = custom right piece
      else {                                                        // character in the middle, could be empty, tip or fill
         if (value_in_pixels <= i*5) {gauge_string[i] = byte(7);}   // empty character
         else if (value_in_pixels > i*5 && value_in_pixels < (i+1)*5) {gauge_string[i] = byte(5-move_offset);} // tip
         else {gauge_string[i] = byte(255);}                        // filled character
      }
  }

  // gauge drawing
  lcd.setCursor(0,0);                         // move cursor to top left
  sprintf(buffer, "val:%3d%% ", val_gauge);    // set a string as val: XX%, with the number always taking at least 3 character
  lcd.print(buffer);                          // print the string on the display
  
  lcd.setCursor(14,0);
  lcd.write(byte(0));                         // print warning character  
  
  lcd.setCursor(0,1);              // move the cursor to the next line
  lcd.print(gauge_string);         // display the gauge

}