Code for the project "Arduino based Smartphone Charging Controller".

Arduino_based_Phone_Charging.ino

#include<LiquidCrystal.h>
#include<EEPROM.h>
LiquidCrystal lcd (8,7,6,5,4,3); 
#define outputA 10 //clk pin of rotary encoder 
#define outputB 11 //dt pin of rotary encoder 
#define button 2   //sw pin of rotary encoder 
#define led 13     //status led
#define relay 12   //in1 of relay

int count = 1; 
int current_state;
int previous_state;  
int hh =0;
int mm=0;
int ss=0;
int h=0;
int m=0;
int s=0;
int ledToggle;
int previousState = HIGH;
unsigned int previousPress;
volatile int buttonFlag;
int buttonDebounce = 20;



void setup() 
{ 
  lcd.begin(16,2);
  pinMode (outputA,INPUT);
  pinMode (outputB,INPUT);
  pinMode (button,INPUT_PULLUP);
  pinMode (led, OUTPUT);
  pinMode (relay, OUTPUT);
  digitalWrite(relay, HIGH);
  attachInterrupt(digitalPinToInterrupt(2), button_ISR, CHANGE);
  Serial.begin (9600);
  previous_state = digitalRead(outputA);   
  
   
    if(EEPROM.read(0)!=0 || EEPROM.read(1)!=0 || EEPROM.read(2)!=0)
    {
      lcd.setCursor(0,0);
      lcd.print("Load Preset ?");
      lcd.print(" ");
      lcd.setCursor(0,1);
      lcd.print("      <NO>      ");
      int temp=5;
      while(temp>0 && ledToggle==0)
      {
        lcd.setCursor(14,0);
        lcd.print(temp);
        temp--;
        delay(1000);
      }
      if(temp==0 && ledToggle==0)
      {
       hh=EEPROM.read(0);
       mm=EEPROM.read(1);
       ss=EEPROM.read(2);
       timer();
      }
      else 
      {
       EEPROM.write(0,0);
       EEPROM.write(1,0);
       EEPROM.write(2,0);
       ledToggle=0;
      }
    }
    lcd.clear();    
    lcd.setCursor(0,0);
    lcd.print(" HH  MM  SS  OK ");
    lcd.setCursor(0,1);
    lcd.print(" 0   0   0      ");
   
} 





void loop() 
{ 
  encoder();
  if(count==1)
  {
    lcd.setCursor(0,0);
      lcd.print("<HH> MM  SS  OK ");
      while(count==1)
      {
        encoder();
        if(ledToggle)
        {
          h=1;
          m=0;
          s=0;
          lcd.setCursor(0,0);
          lcd.print(" HH  MM  SS  OK ");
          lcd.setCursor(1,1);
          lcd.print(hh);
          lcd.setCursor(5,1);
          lcd.print(mm);
          lcd.setCursor(9,1);
          lcd.print(ss);
          lcd.setCursor(0,1);
          lcd.print('<');
          lcd.setCursor(3,1);
          lcd.print('>');
          
          while(ledToggle)
          {
            encoder();
            lcd.setCursor(1,1);            
            lcd.print(hh);
          }
        }
         EEPROM.write(0,hh);
         h=0;
         m=0;
         s=0;
        lcd.setCursor(0,0);
        lcd.print("<HH> MM  SS  OK ");
        lcd.setCursor(0,1);
        lcd.print(' ');
        lcd.setCursor(3,1);
        lcd.print(' ');
      }
  }
  else if(count==2)
   {
    lcd.setCursor(0,0);
      lcd.print(" HH <MM> SS  OK ");
      while(count==2)
      {
        encoder();
        if(ledToggle)
        {
          h=0;
          m=1;
          s=0;
          lcd.setCursor(0,0);
          lcd.print(" HH  MM  SS  OK ");
          lcd.setCursor(1,1);
          lcd.print(hh);
          lcd.setCursor(5,1);
          lcd.print(mm);
          lcd.setCursor(9,1);
          lcd.print(ss);
          lcd.setCursor(4,1);
          lcd.print('<');
          lcd.setCursor(7,1);
          lcd.print('>');
          
          while(ledToggle)
          {
            encoder();
            lcd.setCursor(5,1);            
            lcd.print(mm);
          }
        }
        EEPROM.write(1,mm);
        h=0;
        m=0;
        s=0;
        lcd.setCursor(0,0);
        lcd.print(" HH <MM> SS  OK ");
        lcd.setCursor(4,1);
        lcd.print(' ');
        lcd.setCursor(7,1);
        lcd.print(' ');
      }
  }
  else if(count==3)
  {
    lcd.setCursor(0,0);
      lcd.print(" HH  MM <SS> OK ");
      while(count==3)
      {
        encoder();
        if(ledToggle)
        {
          h=0;
          m=0;
          s=1;
          lcd.setCursor(0,0);
          lcd.print(" HH  MM  SS  OK ");
          lcd.setCursor(1,1);
          lcd.print(hh);
          lcd.setCursor(5,1);
          lcd.print(mm);
          lcd.setCursor(9,1);
          lcd.print(ss);
          lcd.setCursor(8,1);
          lcd.print('<');
          lcd.setCursor(11,1);
          lcd.print('>');
          while(ledToggle)
          {
            encoder();
            lcd.setCursor(9,1);            
            lcd.print(ss);
          }
         EEPROM.write(2,ss);
         h=0;
         m=0;
         s=0;
        }
          lcd.setCursor(0,0);
          lcd.print(" HH  MM <SS> OK ");
          lcd.setCursor(8,1);
          lcd.print(' ');
          lcd.setCursor(11,1);
          lcd.print(' ');
      }
  }
  else if(count==4)
  {
    lcd.setCursor(0,0);
    lcd.print(" HH  MM  SS <OK>");
      while(count==4)
      {
        encoder();
        if(ledToggle)
        {
          timer();
        }
      }
  }
}


void encoder (void)
{
  current_state = digitalRead(outputA);
  if (current_state != previous_state)
  {     
    if (digitalRead(outputB) != current_state) 
    { 
      if(count<4 && ledToggle==0)
      count ++;
      else
      {
        if(h==1)
        {
          if(hh<23)
          hh=hh+1;
        }
        else if(m==1)
        {
          if(mm<59)
          mm=mm+1;
        }
        else if(s==1)
        {
          if(ss<59)
          ss=ss+1;
        }
      }
      
    } 
    else 
    {
      if(count>1 && ledToggle==0)
      count --;
      else
      {
        if(h==1)
        {
          if(hh>0)
          hh=hh-1;
        }
        else if(m==1)
        {
          if(mm>0)
          mm=mm-1;
        }
        else if(s==1)
        {
          if(ss>0)
          ss=ss-1;
        }
      }
    }
    Serial.print("Position: ");
    Serial.println(count);
  } 
  previous_state = current_state; 
  
}

void button_ISR()
{
   buttonFlag = 1;
   if((millis() - previousPress) > buttonDebounce && buttonFlag)
  {
    previousPress = millis();
    if(digitalRead(button) == LOW && previousState == HIGH)
    {
      ledToggle =! ledToggle;
      digitalWrite(led, ledToggle);
      previousState = LOW;
      //Serial.println(ledToggle);
    }
    
    else if(digitalRead(button) == HIGH && previousState == LOW)
    {
      previousState = HIGH;
    }
    buttonFlag = 0;
  }
}

void timer (void)
{
  digitalWrite(relay, LOW);
  while(1)
  {
   lcd.setCursor(0,0);
   lcd.print("Charging...     ");
   lcd.setCursor(0,1);
   if(hh<10)
   {
    lcd.print('0');
    lcd.print(hh);
    lcd.print(':');
   }
   else 
   {
    lcd.print(hh);
    lcd.print(':');
   }
   if(mm<10)
   {
    lcd.print('0');
    lcd.print(mm);
    lcd.print(':');
   }
   else
   {
    lcd.print(mm);
    lcd.print(':');
   }
   if(ss<10)
   {
    lcd.print('0');
    lcd.print(ss);
    lcd.print("          ");
   }
   else
   {
    lcd.print(ss);
    lcd.print("          ");
   }
   Serial.println(ss);
   for(ss;ss>0;ss--)
   {
      Serial.println(ss);
    if(ss<10)
    {
     lcd.setCursor(6,1);
     lcd.print('0');
     lcd.print(ss);
     EEPROM.write(2,ss);
    }
    else
    {
     lcd.setCursor(6,1);
     lcd.print(ss);
     EEPROM.write(2,ss);
    }
    delay(1000);
   }
   if(ss==0 && mm==0 && hh==0)
   {
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Charged");
    digitalWrite(relay, HIGH);
    EEPROM.write(0,0);
    EEPROM.write(1,0);
    EEPROM.write(2,0);
    while(1);
   }
   ss=59;
   if(mm!=0)
   mm=mm-1;
   if(hh!=0)
   hh=hh-1;
   EEPROM.write(0,hh);
   EEPROM.write(1,mm);
   EEPROM.write(2,ss);
   
  }
}