//Power LED on pin 4
//Fault LED on pin 13
//relay module on pin 7
//voltage sensor digital on pin 12
//updated sensor to A0 to monitor voltage

#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

int sensorState = 0;

void setup() {
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
  Serial.println();
  pinMode(7, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(12, INPUT);
  pinMode(13, OUTPUT);
}

void loop() {
lcd.init();
lcd.setCursor(0, 0);
lcd.print("HELLO");
lcd.setCursor(0, 1);
lcd.print("SYSTEM STARTUP");
delay(1000);
startloop:
// Print something
Serial.println("Rebooting");
lcd.init();  
lcd.setCursor(0, 0);
lcd.print("REBOOTING");
for (int i = 0; i <= 10; i++) {
  digitalWrite(4, HIGH);
  delay(500);  
  digitalWrite(4, LOW);
  delay(500);
}
  
  digitalWrite(4, HIGH);
  digitalWrite(7, HIGH);
  delay(500);  
  digitalWrite(7, LOW);
  delay(100); 
  digitalWrite(4, HIGH);
  delay(2000); 
  //exit(0);

  lcd.init();
  monitorloop:
  int sensorValue = analogRead(A0);
  delay(100); 
  float voltage = sensorValue * (5.0 / 1023.0);
  delay(100); 
  if (voltage < 4) {
  //voltage is low
  digitalWrite(13, HIGH);
  lcd.setCursor(0, 0);
  lcd.init();
  lcd.print("FAULT DETECTED");
  lcd.setCursor(0, 1);
  lcd.print(voltage);
  lcd.setCursor(4, 1);
  lcd.print("V");
  Serial.println("Fault detected");
  Serial.println(voltage);
  delay(5000);
  goto startloop;
  } else {
  //voltage is good
  digitalWrite(13, LOW);
  lcd.init();
  lcd.setCursor(0, 0);
  lcd.print("SYSTEM OK");
  lcd.setCursor(0, 1);
  lcd.print(voltage);
  lcd.setCursor(4, 1);
  lcd.print("V");
  Serial.println("System OK");
  Serial.println(voltage);
  delay(5000);
  goto monitorloop;
  }
}