#include <LiquidCrystal_I2C.h>
#include <RTClib.h>

// LCD
LiquidCrystal_I2C lcd(0x27,20,4);

// Ultrasonic sensor
const int trigPin = 5;
const int echoPin = 18;

// Potentiometers
const int turbidityPin = 32;
const int pHPin = 33;
const int tdsPin = 34;
const int flowPin = 35;

// RTC
RTC_DS1307 rtc;

float getDistance() {
  digitalWrite(trigPin, LOW); delayMicroseconds(2);
  digitalWrite(trigPin, HIGH); delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long dur = pulseIn(echoPin,HIGH);
  return dur*0.034/2.0;
}

float readPot(int pin) {
  return map(analogRead(pin),0,4095,0,1000);
}

String getTimeStr() {
  DateTime now = rtc.now();
  char buf[9];
  sprintf(buf,"%02d:%02d:%02d", now.hour(), now.minute(), now.second());
  return String(buf);
}

void setup() {
  Serial.begin(115200);

  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("Overhead Tank ESP");
  delay(2000);
  lcd.clear();

  if(!rtc.begin()){
    Serial.println("RTC not found!");
  }
}

void loop() {
  float level = getDistance();
  float turbidity = readPot(turbidityPin);
  float pH = readPot(pHPin)/100.0*14;
  float tds = readPot(tdsPin);
  float flow = readPot(flowPin);
  String timeStr = getTimeStr();

  // LCD display
  lcd.setCursor(0,0); lcd.print("Lvl:"); lcd.print(level,1);
  lcd.setCursor(0,1); lcd.print("Turb:"); lcd.print(turbidity,0);
  lcd.setCursor(0,2); lcd.print("pH:"); lcd.print(pH,1);
  lcd.setCursor(0,3); lcd.print("Flow:"); lcd.print(flow,1);

  // Serial output
  Serial.print("Overhead Level: "); Serial.print(level,1);
  Serial.print("%, Turbidity: "); Serial.print(turbidity,0);
  Serial.print(", pH: "); Serial.print(pH,1);
  Serial.print(", TDS: "); Serial.print(tds,0);
  Serial.print(", Flow: "); Serial.print(flow,0);
  Serial.print(", Time: "); Serial.println(timeStr);

  delay(2000);
}