#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd (0x27, 20,4);

#define T_OFF_STATE 0
#define T_ON_STATE  1

int state = T_OFF_STATE;    // set initial state
int Relay = 4;              // set output solinoid 
int t_on_show,t_off_show;

long tt_on,tt_off;

long Time_on , Time_off;

unsigned long previousTime_Scan = millis();
long timeInterval_Scan = 1000;

unsigned long timer1 = millis();
unsigned long currentTime = millis();

void setup() {
  Serial.begin(9600);      // set broad rate
  lcd.begin(20,4);             // set lcd  
  lcd.backlight();         // on blacklight
  pinMode(Relay,OUTPUT);   // set pin output
  lcd.setCursor(0,3);
  lcd.print("Loop Time ");
}

void loop() {
  unsigned long currentTime = millis();
  //----------------------- task 1  -----------------------
  if(currentTime - previousTime_Scan > timeInterval_Scan) {  // เมื่อถึงเวลา 1 วินาที จะทำการอ่านค่าใหม่ตลอด
             previousTime_Scan = currentTime;
             tt_on = analogRead(A0);
             tt_on = map(tt_on,0,1023,0,60);
             Time_on = tt_on * 60000;
             t_on_show = map(Time_on,0,360000,0,60)/10;
             Serial.println(Time_on);
             tt_off = analogRead(A1);
             tt_off = map(tt_off,0,1023,0,60);
             Time_off = tt_off * 60000;
             t_off_show = map(Time_off,0,360000,0,60)/10;
             Serial.println(Time_off);  
           }
  switch (state){
    case T_OFF_STATE:
        Serial.println("T_OFF");
        digitalWrite(Relay,LOW);
        lcd.setCursor(14,2);
        lcd.print(" OFF ");
        if (millis() - timer1 >= Time_off){
          timer1 = millis();
          state = T_ON_STATE;
        }
    break;
    case T_ON_STATE:
        Serial.println("T_ON");
        digitalWrite(Relay,HIGH);
        lcd.setCursor(14,2);
        lcd.print(" ON ");
        if (millis() - timer1 >= Time_on){
          timer1 = millis();
          state = T_OFF_STATE;
        } 
    break;
  }
 show();  
}

void show()
{
  lcd.setCursor(0,0);
  lcd.print("Time On = ");
  lcd.print(t_on_show);
  lcd.print(" Min ");

  lcd.setCursor(0,1);
  lcd.print("Time Off = ");
  lcd.print(t_off_show);
  lcd.println(" Min ");

  lcd.setCursor(0,2);
  lcd.print("Status : Water");

  lcd.setCursor(0,3);
  lcd.print("Loop Time ");
  lcd.print(t_on_show + t_off_show);
  lcd.print(" Min ");
}