// pulse an output if switch changes to low
// using a finite state machine
// https://forum.arduino.cc/t/switching-circuit-using-relays-and-ups-with-arduino/1019626/

#define DEBUG 1    // 1 debug messages, 0 off
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

int UPSrestrtCount = 0;      // Integer for UPS restart count if it failed to start
int period = 2000;           // Voltage update delay time (ms)
unsigned long time_now = 0;
const word PWM_FREQ_HZ = 25000; //Adjust this value to adjust the frequency
const word TCNT1_TOP = 16000000/(2*PWM_FREQ_HZ);
#define SIGNAL_PIN A0        // Define analog input for voltage measurement
float adc_voltage = 0.0;     //   Floats for ADC voltage 
float in_voltage = 0.0;      //   Floats for  Input voltage
float R1 = 100000.0;         //   Resistor values in Voltage divider (in ohms)
float R2 = 20000.0;          //   Resistor values in Voltage divider (in ohms)
float ref_voltage = 5.0;     //   Float for Reference Voltage
float thres_voltage = 1.007222216606498;     //  Threshold voltage for calibration
float CHOFF_voltage = 28.1;     //  Charger Turn OFF voltage
float CHON_voltage  = 27.3;     //  Charger Turn ON voltage
int adc_value = 0;           //   Integer for ADC value
byte Battery[] = {
  0x00,
  0x04,
  0x0E,
  0x0E,
  0x0E,
  0x0E,
  0x0E,
  0x00
};

byte BatteryCharging[] = {
  0x00,
  0x02,
  0x04,
  0x08,
  0x1E,
  0x04,
  0x08,
  0x10
};

/* The easy circuit for temperature measurement with 10K thermistor:
 *                  Analog pin 2,3
 *                        |
 *    5V |-----/\/\/\-----+-----/\/\/\-----| GND
 *               ^                ^ 
 *        10K thermistor     10K resistor
 */


#define ThermistorPin A2 // First 10K thermistor connected at PIN A2 (For Ambient Temp. Measurement)
#define Thermistor2Pin A3 // Second 10K thermistor connected at PIN A3 (For UPS Temp. Measurement )
long A2_Value;
long A3_Value;
float RT1 = 10000; // Value of Resistor connected in series with First Thermistor
float logRT2, RT2, T;
float RT3 = 10000; //  Value of Resistor connected in series with Second Thermistor
float logRT4, RT4, T2;
float c1 = 0.001129148, c2 = 0.000234125, c3 = 0.0000000876741;  //steinhart-hart coeficients for thermistor
float temp_c, temp_c2, temp_f, temp_f2;
float FNOFF_temp = 1;     //  Minimum Temperature difference in °C at which FANs are Turned OFF
float FNON_temp  = 4;     //  Minimum Temperature difference in °C at which FANs are Turned ON
byte FAN1[] = {
  0x00,
  0x00,
  0x04,
  0x04,
  0x1F,
  0x04,
  0x04,
  0x00
};
byte FAN2[] = {
  0x00,
  0x00,
  0x11,
  0x0A,
  0x04,
  0x0A,
  0x11,
  0x00
};

#if defined(ARDUINO) && ARDUINO >= 100
#define printByte(args)  write(args);
#else
#define printByte(args)  print(args,BYTE);




#endif

LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display

constexpr uint8_t UPSsupply {4};         // Current state of UPS (ON/OFF)
constexpr uint8_t FANrelay {6};            // Cooling FAN relay
constexpr uint8_t MAINSsupply {7};         // AC power detection using a 5v charger
constexpr uint8_t button {8};              // Push button detection
const byte        OC1A_PIN = 9;
constexpr uint8_t CHARGErelay {10};        // Battery Charger relay
//constexpr uint8_t upsSwitch {11};        // connected to UPS on/off switch
constexpr uint8_t MAINSrelay {12};         // MAINS relay
constexpr uint8_t UPSrelay {13};            // UPS relay

constexpr uint16_t intervalOn {300};      // pulse time for UPS ON signal
constexpr uint16_t intervalOff {5000};     // pulse time for UPS OFF signal
constexpr uint16_t intervalWarning {3000}; // time before UPS will get switched on
constexpr uint16_t intervalUPS {30000};     // Waiting Time for UPS to turn off properly.
constexpr uint16_t intervalRecover {5000}; // time before UPS will be switched off
constexpr uint16_t intervalCheckMAINS {10000}; // MAINS checking Time
constexpr uint16_t intervalLCD {30000};    // LCD light TURN ON Time

enum class State {INITIALIZE,              // Check if Mains is available
                  IDLE,                    // AC is on,  waiting fo AC black out
                  WARNING,                 // AC is off, waiting for UPS switch on
                  MAINSRELAY_OFF,
                  UPSRELAY_ON,
                  FAIL,                    // AC is off, waiting for AC coming back
                  RECOVER,                 // AC is on,  recovering period, AC is back but we keep UPS running
                  UPSRELAY_OFF,            // UPS RELAY Off
                  BACK                     // preparing things back for idle
                 };                       
// a class to pulse a pin - nonblocking
class PulsePin
{
    const uint8_t pin;
    uint32_t previousMillis = 0;
    uint32_t lcdPreviousMillis = 0;
    bool state = LOW;              // state of the pin    
    uint16_t interval = intervalOn;
  public:
    PulsePin (const uint8_t pin ) : pin (pin) {}
    void begin()
    {
      pinMode(pin, OUTPUT);
    }
    void pulse(uint16_t interval)
    {
      this->interval = interval;
      digitalWrite(pin, HIGH);
      previousMillis = millis();
      state = HIGH;
    }
    void update()
    {
      if (state && millis() - previousMillis > interval )
      {
        digitalWrite(pin, LOW);
        state = LOW;
      }
    }
};
PulsePin upsSwitch(11);


void checkAC()
{
  static uint32_t previousMillis = 0;          // timestamp for state machine
  static uint32_t lcdPreviousMillis = 0;
  static State state {State::INITIALIZE};            // current state
  static uint8_t previousInputState = HIGH;    // previous state of input circuit / AC  
  uint8_t inputState = digitalRead(MAINSsupply);  // current state of input circuit / AC
  uint8_t UPSstate = digitalRead(UPSsupply);  // current state of UPS (ON/OFF)
  static uint8_t previousinputbutton = HIGH;    // previous state of push button
  uint8_t inputbutton = digitalRead(button);  // current state of push button
  static uint8_t CHARGER = HIGH;
  static uint8_t FAN = LOW;
  static uint8_t UPS = LOW;
 

  

  
  switch (state)
  {   case State::INITIALIZE :
      lcd.setCursor(0, 0 );
      lcd.print("INITIALIZING ");
      lcd.setCursor(0, 1 );
      lcd.print("PLEASE WAIT..."); 
      UPSrestrtCount = 0;      
      digitalWrite(CHARGErelay, HIGH);  //  Battery Charger turned ON
      digitalWrite(FANrelay, HIGH);  //  FANs turned ON  
      setPwmDuty(100);         //  Full Speed
      FAN = HIGH   ;
      if (millis() - previousMillis > intervalUPS) 
      {
        if (inputState == HIGH && UPSstate == HIGH )  // check for AC presence
        if (millis() - previousMillis > intervalRecover)
        {
        Serial.println(F("\nAC ON, UPS ON - Turn OFF UPS - Re-Initialize"));
        lcd.setCursor(0, 0 );
        lcd.print("UPS OFF      ");
        digitalWrite(UPSrelay, LOW);  //  UPS relay turned OFF 
        digitalWrite(MAINSrelay, LOW);  //  MAINS relay turned OFF(MAINS ON)
        upsSwitch.pulse(intervalOff);  // switching UPS OFF      
        previousMillis = millis(); 
        lcd.clear();
        lcd.setCursor(14, 1);
        lcd.print ("ON");                  
        state = State::INITIALIZE;           //  Go back to Intialize Mode
       }
        if (inputState == HIGH && UPSstate == LOW )  // check for AC presence
        if (millis() - previousMillis > intervalWarning)
       {
        Serial.println(F("\nAC ON - Enter IDLE"));
        digitalWrite(UPSrelay, LOW);  //  UPS relay turned OFF 
        digitalWrite(MAINSrelay, LOW);  //  MAINS relay turned OFF(MAINS ON)
        previousMillis = millis(); 
        //lcd.clear();
        //lcd.setCursor(14, 1);
        //lcd.print ("ON"); 
        setPwmDuty(10);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("IDLE...   "); 
        lcd.setCursor(9, 0);
        lcd.write(byte(0));        
        lcd.createChar(0,BatteryCharging);               
        state = State::IDLE;         
       }
       if (inputState == LOW && UPSstate == LOW )  // check for AC fail
       if (millis() - previousMillis > intervalWarning)
       {
        Serial.println(F("\nAC off - Enter WARNING"));
        previousMillis = millis();
        lcd.clear();       
        state = State::WARNING;      
       }
       if (inputState == LOW && UPSstate == HIGH )  // check for AC fail
       if (millis() - previousMillis > intervalRecover)
       {
        Serial.println(F("\nAC off, UPS ON - Turn OFF UPS - Re-Initialize"));
        previousMillis = millis();
        digitalWrite(UPSrelay, LOW);  //  UPS relay turned OFF 
        digitalWrite(MAINSrelay, LOW);  //  MAINS relay turned OFF(MAINS ON)
        upsSwitch.pulse(intervalOff);  // switching UPS OFF  
        lcd.clear();       
        state = State::INITIALIZE;       //  Go back to Intialize Mode
        }

      }
      break;
      case State::IDLE :       
      //lcd.setCursor(0, 0);
      //lcd.print("IDLE...   ");
      for(int i=0; i< 49; i++) {               
      adc_value = analogRead(SIGNAL_PIN);    //   measure voltage at PIN A0
      }
      in_voltage = adc_value * (5.0/1024)*((R1 + R2)/R2);
      in_voltage = thres_voltage *  in_voltage;            //  Threshold For Voltage calibration.
      //adc_voltage  = (adc_value * ref_voltage) / 1024.0;
      //in_voltage = adc_voltage / (R2 / (R1 + R2)) ;      
      //digitalWrite(CHARGErelay, HIGH);  //  CHARGER turned ON 
      if (in_voltage >= CHOFF_voltage && CHARGER == HIGH)  // if battery voltage is >= 28.1 , turn OFF charger
      { 
        digitalWrite(CHARGErelay, LOW);  //  Battery Charger turned OFF
        //lcd.setCursor(13, 1);
        //lcd.print ("    ");
        lcd.setCursor(9, 0);
        lcd.write(byte(0));
        //lcd.print ("OFF");
        lcd.createChar(0,Battery);
        Serial.println(F("\nCharger turned OFF"));
        digitalWrite(FANrelay, LOW);  //  FANs turned OFF   
        FAN = LOW ;
        CHARGER = LOW;
      }
      if (in_voltage <= CHON_voltage && CHARGER == LOW)  // if battery voltage is <= 27.5 , turn ON charger
      { 
        digitalWrite(CHARGErelay, HIGH);  //  Battery Charger turned ON
        lcd.setCursor(9, 0);
        lcd.write(byte(0));
        //lcd.print (" ON");
        lcd.createChar(0,BatteryCharging);
        Serial.println(F("\nCharger turned ON"));
        digitalWrite(FANrelay, HIGH);  //  FANs turned ON 
        FAN = HIGH;
        CHARGER = HIGH;
      }
       if(millis() >= time_now + period){
        time_now += period;         
      //Serial.print("Input Voltage = ");
      //Serial.println(in_voltage, 2);
      lcd. setCursor (10, 0);
      lcd.print (in_voltage, 2);
      lcd.print ("V");
      //Serial.println(" ");
      
      A2_Value=0;               //   Start Temperature calculation for First thermistor (For Ambient) on PIN A2
      for(int i=0; i< 50; i++) {
      A2_Value = A2_Value + analogRead(ThermistorPin);
      }
      A2_Value=A2_Value/50;
      RT2 = RT1 * (1023.0 / (float)A2_Value - 1.0); //calculate resistance on thermistor
      logRT2 = log(RT2);
      temp_c = (1.0 / (c1 + c2*logRT2 + c3*logRT2*logRT2*logRT2)); // temperature in Kelvin
      temp_c = temp_c - 273.15; //convert Kelvin to Celcius
      temp_f = (temp_c * 9.0)/ 5.0 + 32.0; //convert Celcius to Fahrenheit
      lcd.setCursor (0, 1 );
      lcd.print(temp_c, 1); 
      lcd.write(0xdf); // to display °
      lcd.print("C  "); 

      A3_Value=0;                //   Start Temperature calculation for Second thermistor (For UPS) on PIN A3
      for(int i=0; i< 50; i++) {
      A3_Value = A3_Value + analogRead(Thermistor2Pin);
      }
      A3_Value=A3_Value/50;
      RT4 = RT3 * (1023.0 / (float)A3_Value - 1.0); //calculate resistance on thermistor
      logRT4 = log(RT4);
      temp_c2 = (1.0 / (c1 + c2*logRT4 + c3*logRT4*logRT4*logRT4)); // temperature in Kelvin
      temp_c2 = temp_c2 - 273.15; //convert Kelvin to Celcius
      temp_f2 = (temp_c2 * 9.0)/ 5.0 + 32.0; //convert Celcius to Fahrenheit
      lcd.setCursor (10, 1 );
      lcd.print(temp_c2, 1); 
      lcd.write(0xdf); // to display °
      lcd.print("C  ");

      if(temp_c2 - temp_c >= FNON_temp && FAN == LOW){  // if Temp. difference of both thermistor is more than FANON_temp, turn ON FAN
       digitalWrite(FANrelay, HIGH);    // FAN turned ON
       setPwmDuty(10);
       Serial.print("FAN ON");
       FAN = HIGH;
       }
       if(temp_c2 - temp_c <= FNOFF_temp && FAN == HIGH){  // if Temp. difference of both thermistor is more than FANOFF_temp, turn OFF FAN
       digitalWrite(FANrelay, LOW);
       setPwmDuty(0);
       Serial.print("FAN OFF");
       FAN = LOW;
       } 
      
     }
     if (millis() - lcdPreviousMillis>=intervalLCD)
      {
        lcd.noBacklight();
      }
     if (digitalRead(button) == HIGH)
      { 
       Serial.println(F("\nButton Pressed"));
       previousMillis = millis();
       lcdPreviousMillis = millis();
       lcd.backlight();
       lcd.setCursor (10, 1 );
       lcd.print(temp_c, 1);
      }
     if (millis() - lcdPreviousMillis>=intervalLCD)
      {
       lcd.noBacklight();
      }  
      if (inputState == LOW && previousInputState == HIGH)  // check for AC fail
      {
        Serial.println(F("\nAC off - Enter WARNING"));
        previousMillis = millis();
        lcdPreviousMillis = millis();
        lcd.backlight();
        state = State::WARNING;
      }
      break;
     case State::WARNING :
      lcd.setCursor(0, 0 );
      lcd.print("WARNING   ");
      lcd.setCursor(0, 1 );
      lcd.print("POWER FAIL      ");
      if (inputState == HIGH && previousInputState == LOW)  // check for AC back
      {
        Serial.println(F("\nAC on again - go back to IDLE"));
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("IDLE...   "); 
        lcd.setCursor(9, 0);
        lcd.write(byte(0));        
        lcd.createChar(0,BatteryCharging); 
        state = State::IDLE;
      }
      if (millis() - previousMillis > intervalWarning)
      {
        Serial.println(F("\nAC off --> MAINSRELAY_OFF"));
        digitalWrite(MAINSrelay, HIGH);  //  MAINS relay turned ON (MAINS OFF)
        previousMillis = millis();
        state = State::MAINSRELAY_OFF;
      }
      break;
     case State::MAINSRELAY_OFF :
      lcd.setCursor(0, 0 );
      lcd.print("TURNING ");
      lcd.setCursor(0, 1 );
      lcd.print("MAINS RELAY OFF ");
      if (inputState == HIGH && previousInputState == LOW)  // check for AC back again
      {
        Serial.println(F("\nAC on again Turning MAINSrealy ON and go back to IDLE"));
        previousMillis = millis();
        digitalWrite(MAINSrelay, LOW);  //  MAINS relay turned OFF again (MAINS ON)
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("IDLE...   "); 
        lcd.setCursor(9, 0);
        lcd.write(byte(0));        
        lcd.createChar(0,BatteryCharging); 
        state = State::IDLE;
      }
      if (millis() - previousMillis > intervalWarning)
      {
        Serial.println(F("\nAC off --> UPSRELAY_ON"));
        digitalWrite(UPSrelay, HIGH);  //  UPS relay turned ON
        previousMillis = millis();
        state = State::UPSRELAY_ON;
      }    
     break;
     case State::UPSRELAY_ON :
      lcd.setCursor(0, 0 );
      lcd.print("TURNING ");
      lcd.setCursor(0, 1 );
      lcd.print(" ON UPS           ");
      if (inputState == HIGH && previousInputState == LOW)  // check for AC back again
      {
        Serial.println(F("\nAC on again Turning MAINSrealy ON and go back to IDLE"));
        previousMillis = millis();
        digitalWrite(UPSrelay, LOW);  //  UPS relay turned OFF again
        digitalWrite(MAINSrelay, LOW);  //  MAINS relay turned OFF again (MAINS ON)
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("IDLE...   "); 
        lcd.setCursor(9, 0);
        lcd.write(byte(0));        
        lcd.createChar(0,BatteryCharging); 
        state = State::IDLE;  
      }
      if (millis() - previousMillis > intervalWarning)
      {
        Serial.println(F("\nAC off --> FAIL"));
        lcdPreviousMillis = millis();
        previousMillis = millis(); 
        upsSwitch.pulse(intervalOn); // switching UPS ON
        digitalWrite(CHARGErelay, LOW);  //  Battery Charger turned OFF
        digitalWrite(FANrelay, HIGH);  //  FANs turned ON 
        setPwmDuty(100); 
        FAN = HIGH ;
        state = State::FAIL;
      }    
     break;
     case State::FAIL :      
      lcd.setCursor(0, 0 );
      lcd.print("MAINS FAIL");
      lcd.setCursor(0, 1 );
      //lcd.print("  LOAD ON UPS       ");
      adc_value = analogRead(SIGNAL_PIN);
      in_voltage = adc_value * (5.0/1024)*((R1 + R2)/R2);
      in_voltage = thres_voltage *  in_voltage;            //  Threshold For Voltage calibration.
      //adc_voltage  = (adc_value * ref_voltage) / 1024.0;     
      //in_voltage = adc_voltage / (R2 / (R1 + R2)) ;
      if(millis() >= time_now + period){
      time_now += period;         
      Serial.print("Input Voltage = ");
      Serial.println(in_voltage, 2);
      lcd. setCursor (10, 0);
      lcd.print (in_voltage, 2);
      lcd.print ("V ");
      Serial.println(" ");

      A2_Value=0;               //   Start Temperature calculation for First thermistor (For Ambient) on PIN A2
      for(int i=0; i< 50; i++) {
      A2_Value = A2_Value + analogRead(ThermistorPin);
      }
      A2_Value=A2_Value/50;
      RT2 = RT1 * (1023.0 / (float)A2_Value - 1.0); //calculate resistance on thermistor
      logRT2 = log(RT2);
      temp_c = (1.0 / (c1 + c2*logRT2 + c3*logRT2*logRT2*logRT2)); // temperature in Kelvin
      temp_c = temp_c - 273.15; //convert Kelvin to Celcius
      temp_f = (temp_c * 9.0)/ 5.0 + 32.0; //convert Celcius to Fahrenheit
      lcd.setCursor (0, 1 );
      lcd.print(temp_c, 1); 
      lcd.write(0xdf); // to display °
      lcd.print("C  "); 

      A3_Value=0;                //   Start Temperature calculation for Second thermistor (For UPS) on PIN A3
      for(int i=0; i< 50; i++) {
      A3_Value = A3_Value + analogRead(Thermistor2Pin);
      }
      A3_Value=A3_Value/50;
      RT4 = RT3 * (1023.0 / (float)A3_Value - 1.0); //calculate resistance on thermistor
      logRT4 = log(RT4);
      temp_c2 = (1.0 / (c1 + c2*logRT4 + c3*logRT4*logRT4*logRT4)); // temperature in Kelvin
      temp_c2 = temp_c2 - 273.15; //convert Kelvin to Celcius
      temp_f2 = (temp_c2 * 9.0)/ 5.0 + 32.0; //convert Celcius to Fahrenheit
      lcd.setCursor (10, 1 );
      lcd.print(temp_c2, 1); 
      lcd.write(0xdf); // to display °
      lcd.print("C  ");  
     }
      if (millis() - lcdPreviousMillis>=intervalLCD)
      {
        lcd.noBacklight();
      }
      if (digitalRead(button) == HIGH)
      { 
       Serial.println(F("\nButton Pressed"));
       previousMillis = millis();
       lcdPreviousMillis = millis();
       lcd.backlight();
      }
     if (millis() - lcdPreviousMillis>=intervalLCD)
      {
       lcd.noBacklight();
      }
      if (UPSstate == LOW && UPSrestrtCount<=2 )    //     Try to restart UPS in case of Fault.
      if (millis() - previousMillis > intervalCheckMAINS) 
      {
        Serial.println(F("\nUPS fault Turning ON again"));
        previousMillis = millis();
        upsSwitch.pulse(intervalOff); // switching UPS ON        
        UPSrestrtCount = UPSrestrtCount + 1;        
      }

      if (inputState == HIGH && previousInputState == LOW)
      {
        Serial.println(F("\nAC on --> Checking If Mains is Stable"));
        previousMillis = millis();
        lcd.backlight();
        state = State::RECOVER;
      }
      break;
      case State::RECOVER :
      lcd.setCursor(0, 0 );
      lcd.print("MAINS OK  ");
      lcd.setCursor(0, 1 );
      lcd.print("SWITCHINGTOMAINS");
      if (inputState == LOW && previousInputState == HIGH)
      {
        Serial.println(F("\nAC off - Not Stable --> go back to FAIL"));  
        lcd.backlight(); 
        lcdPreviousMillis = millis();     
        state = State::FAIL;
      }
      if (millis() - previousMillis > intervalCheckMAINS)
      {
        Serial.println(F("\nAC on - MAINS Stable --> UPSRELAY_OFF"));
        digitalWrite(UPSrelay, LOW);  //  UPS relay turned OFF
        previousMillis = millis();
        state = State::UPSRELAY_OFF;
      }
      break;
      case State::UPSRELAY_OFF :
      lcd.setCursor(0, 0 );
      lcd.print("TURNING   ");
      lcd.setCursor(0, 1 );
      lcd.print("UPS RELAY  OFF       ");
      if (inputState == LOW && previousInputState == HIGH)  // check for AC fail again in between
      {
        Serial.println(F("\nAC OFF in Between, Turning UPSRELAY ON again"));
        digitalWrite(UPSrelay, HIGH);  //  UPS relay turned ON again
        previousMillis = millis();
        state = State::FAIL;
      }
      if (millis() - previousMillis > intervalRecover)
      {
        Serial.println(F("\nAC on --> Turn OFF UPS"));
        upsSwitch.pulse(intervalOff);  // switching UPS OFF
        previousMillis = millis();  
        state = State::BACK;
      }
      break;
      case State::BACK :
      lcd.setCursor(0, 0 );
      lcd.print("GOING BACK");
      lcd.setCursor(0, 1 );
      lcd.print(" TO IDLE MODE      ");
      if (inputState == LOW && previousInputState == HIGH)  // check for AC fail again in between
      {
        Serial.println(F("\nAC OFF in Between, Turning UPSRELAY ON again"));
        previousMillis = millis();
        state = State::INITIALIZE;
      } 
      if (millis() - previousMillis > intervalRecover)
      {
        Serial.println(F("\nAC on - longer than timelimit --> IDLE again"));
        digitalWrite(MAINSrelay, LOW);  //  MAINS relay turned OFF (MAINS ON)
        previousMillis = millis();
        lcdPreviousMillis = millis();
        lcd.clear();
        CHARGER = HIGH;
        setPwmDuty(10);
        digitalWrite(CHARGErelay, HIGH);  //  Battery Charger turned OFF
        state = State::INITIALIZE;
        //state = State::IDLE;
      }
      break;
  }
 previousInputState = inputState;
  delay(20); // this dirty delay is just to debounce switches
}

// this function gets called during delays. 
// so we use it also to check if we have to do something with the pulsePin
void yield()
{
  upsSwitch.update(); 
}


void setup() {
  
  lcd.init();                      // initialize the lcd 
  lcd.backlight();  
  Serial.begin(115200);
  Serial.println(F("Initializing Please Wait..."));
  lcd.createChar(0, Battery);
  lcd.createChar(0, BatteryCharging);
  upsSwitch.begin();
  pinMode(UPSrelay, OUTPUT);
  pinMode(MAINSrelay, OUTPUT);
  pinMode(CHARGErelay, OUTPUT);
  pinMode(FANrelay, OUTPUT);
  pinMode(button, INPUT);
  //pinMode(UPSsupply, INPUT);
  pinMode(OC1A_PIN, OUTPUT);
   TCCR1A = 0;
  TCCR1B = 0;
  TCNT1  = 0;

  // Set Timer1 configuration
  // COM1A(1:0) = 0b10   (Output A clear rising/set falling)
  // COM1B(1:0) = 0b00   (Output B normal operation)
  // WGM(13:10) = 0b1010 (Phase correct PWM)
  // ICNC1      = 0b0    (Input capture noise canceler disabled)
  // ICES1      = 0b0    (Input capture edge select disabled)
  // CS(12:10)  = 0b001  (Input clock select = clock/1)
  
  TCCR1A |= (1 << COM1A1) | (1 << WGM11);
  TCCR1B |= (1 << WGM13) | (1 << CS10);
  ICR1 = TCNT1_TOP;
  delay(50);
}

void setPwmDuty(byte duty) {
  OCR1A = (word) (duty*TCNT1_TOP)/100;
}

void loop() {
  checkAC();
  upsSwitch.update(); // must be called in loop - no delays allowed ;-)
}