#include <LiquidCrystal.h>

/* Display */
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

byte statusLed = 13;

byte sensorInterrupt = 0; 
byte sensorPin = 2;       

float calibrationFactor = 4.8; // YF-G1 DN25 1inch Water Flow Sensor

volatile byte pulseCount;

float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;

unsigned long oldTime;
unsigned long current_value=0;
////////////////////////////////
const int btn_enter = 6;
const int btn_up = 5;
const int btn_down = 4;
const int btn_left = 3;

signed long setpoint_value=0;
String v;
char str[17];
char str_num[10];
int mode=0;

unsigned int cursor_loc=1;

unsigned long multiple_value(int v);

void setup()
{
    // Initialize a serial connection for reporting values to the host
    Serial.begin(9600);

    // Set up the status LED line as an output
    pinMode(statusLed, OUTPUT);
    digitalWrite(statusLed, HIGH); // We have an active-low LED attached

    pinMode(sensorPin, INPUT);
    digitalWrite(sensorPin, HIGH);

    pulseCount = 0;
    flowRate = 0.0;
    flowMilliLitres = 0;
    totalMilliLitres = 0;
    oldTime = 0;

    // The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
    // Configured to trigger on a FALLING state change (transition from HIGH
    // state to LOW state)
    attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
    
    lcd.begin(16, 2);
    //init_icons(lcd);
    delay(100);
    
    lcd.clear();
  
    pinMode(btn_enter, INPUT);
    pinMode(btn_up, INPUT);
    pinMode(btn_down, INPUT);
    pinMode(btn_left, INPUT);
}

void loop()
{   
  if (mode == 0){
    setpoint();
  }else{
    if ((millis() - oldTime) > 1000) // Only process counters once per second
    {
        detachInterrupt(sensorInterrupt);
        flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor; // F = 4.8 * Q => Q = F/4.8 (L/min)
        oldTime = millis();
        flowMilliLitres = (flowRate / 60) * 1000;
        totalMilliLitres += flowMilliLitres;

        unsigned int frac;

        // Print the flow rate for this second in litres / minute
        Serial.print("Flow rate: ");
        Serial.print(int(flowRate)); // Print the integer part of the variable
        Serial.print("L/min");
        Serial.print("t"); // Print tab space

        // Print the cumulative total of litres flowed since starting
        Serial.print("Output Liquid Quantity: ");
        Serial.print(totalMilliLitres);
        Serial.println("mL");
        Serial.print("t"); // Print tab space
        Serial.print(totalMilliLitres / 1000);
        Serial.print("L");

        // Reset the pulse counter so we can start incrementing again
        pulseCount = 0;

        // Enable the interrupt again now that we've finished sending output
        attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
    }
  }
}
/*
Insterrupt Service Routine
 */
void pulseCounter()
{
    // Increment the pulse counter
    pulseCount++;
}
void checkbutton(){
    if (digitalRead(btn_up) == 0){
   delay(150);
    if (digitalRead(btn_up) == 0){
      //unsigned long value = pow(10,cursor_loc);
        Serial.println(setpoint_value);
       Serial.println(multiple_value(cursor_loc));
      setpoint_value = (signed long)setpoint_value + (signed long)multiple_value(cursor_loc) ;
      Serial.println(setpoint_value);
      if (setpoint_value > 99999) setpoint_value=0;
      dislay_change_value_setpoint();
      }
  }
  //
    if (digitalRead(btn_down) == 0){
    delay(150);
    if (digitalRead(btn_down) == 0){
      //unsigned long value = pow(10,cursor_loc);
       
      setpoint_value = setpoint_value - (signed long)multiple_value(cursor_loc) ;
      if (setpoint_value < 0) setpoint_value=0;
      dislay_change_value_setpoint();
      }
  }
  //
  if (digitalRead(btn_left) == 0){
    delay(150);
    if (digitalRead(btn_left) == 0) {
      cursor_loc++;
      if (cursor_loc >=5) cursor_loc =0;
      lcd.setCursor(strlen(str_num)-1-cursor_loc, 1);
    }
  }
  //
  if (digitalRead(btn_enter) == 0){
    delay(150);
    if (digitalRead(btn_enter) == 0) 
     mode=1;
  }
  
  }
void setpoint(){
  
  dislay_setpoint();
  cursor_loc =0;
  lcd.setCursor(strlen(str_num)-1, 1);
  lcd.blink();

  while(mode ==0){
      checkbutton();
    }
  lcd.noBlink();
 
  mode=1;
  start_mode();
  }
void start_mode(){
  lcd.setCursor(0, 0);
  snprintf(str_num, sizeof(str_num), "VOLUME %05ld", current_value); 
  lcd.print(str_num);
  }
void dislay_setpoint(){
  lcd.clear();
  lcd.setCursor(0, 1);
  //    int whole = (int)l;                      // phần nguyên
//    int frac = (int)((l - whole) * 10); // làm tròn 1 chữ số
//    snprintf(str_num, sizeof(str_num), "SET %3d.%01d", whole, frac); setpoint_value
  snprintf(str_num, sizeof(str_num), "SET %05ld", setpoint_value); 
  lcd.print(str_num);
  lcd.setCursor(0, 0);
  lcd.print("Setpoint ..."); 
  }

void dislay_change_value_setpoint(){
  lcd.setCursor(0, 1);
  snprintf(str_num, sizeof(str_num), "SET %05ld", setpoint_value); 
  lcd.print(str_num);
  lcd.setCursor(strlen(str_num)-1-cursor_loc, 1);
  }
unsigned long multiple_value(int v){
  switch(v){
    case 0:
      return 1;
    case 1:
      return 10;
    case 2:
      return 100;
    case 3:
      return 1000;
    case 4:
      return 10000;
    default:
      return 1;
  }
}