// https://forum.arduino.cc/t/i-have-problem-in-automatic-transfer-switch-
// it-doesnt-update-pins-on-arduino-nano-if-i-
// run-when-main-supply-is-on-it-display-supply-but-donot-update/1247207

#include <TimerOne.h>
// include the library code:
//#include <LiquidCrystal.h> //library for LCD
#include <LiquidCrystal_I2C.h>
#define potinput  A0
#define feedbackinput  A1
#define Main_Check  A2
#define outA  9
#define outB  10
#define main 8
#define ups 7
// initialize the library with the numbers of the interface pins
//LiquidCrystal lcd(12, 11, 6, 5, 4, 3);
LiquidCrystal_I2C lcd(0x27, 20, 4);    // Inicializa o objeto LiquidCrystal_I2C
const int Main_Relay = A3;
//const int Ups_Relay  = A4;
const int Ups_Relay  = 12;
const int Ups_Start  =  7;
int f_pwm = 20000; //max 20000
int f_sine = 50;
float sinus[200];
float phi = 3.14;
int flag = 0;
int sample = 0, samples = 0;
int potinputval;
int feedbackinputval;
int A;
int max_power = 800; //max 1023
float invert = 0.0;
int total_sample;
int phase = 0, x = 0;
//----------------------------------------------------------
void setup() {
  total_sample = round((((1000000. / f_sine) / (1000000. / f_pwm)) / 2.));
  for (int sudut = 0; sudut < total_sample; sudut++)
  {
    float rad = sudut * (180. / total_sample) * phi / 180;
    sinus[sudut] = sin(rad);
  }
  float t_pwm = (1000000. / f_pwm);
  pinMode(potinput, INPUT);
  pinMode(feedbackinput, INPUT);
  pinMode(Main_Check, INPUT);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(Ups_Start, OUTPUT);
  pinMode(Main_Relay, OUTPUT);
  pinMode(Ups_Relay, OUTPUT);
  //lcd.begin(20, 4); // set up the LCD's number of columns and rows:
  lcd.init(); // inicia o display 16x2
  lcd.setCursor(0, 0);
  lcd.print(" FINAL YEAR PROJECT ");
  lcd.setCursor(0, 1);
  lcd.print("  INTELLIGENT UPS   ");
  delay(100);
  A = 0;
  Timer1.initialize(t_pwm);
  Timer1.attachInterrupt(generate_sinus);
  //samples=(total_sample*2/3);
  Timer1.pwm(outA, (sinus[sample]* A));
  Timer1.pwm(outB, (sinus[sample]* A));
}
//----------------------------------------------------------
void loop() {
  // Measure The Votage ***********************************
  int sensorValue = analogRead(Main_Check);  // read the input on analog pin A2
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float vol = (sensorValue * 5.0) / 1023.0;  //
  int voltage = vol * 5;
  lcd.setCursor(14, 3);    //For debug
  lcd.print(voltage);  //For debug
  if (voltage < 5)  {
    digitalWrite(Ups_Start, HIGH);  // 7
    digitalWrite(Main_Relay, LOW);  // A3
    digitalWrite(Ups_Relay, HIGH);  // A4  (12)
    lcd.setCursor(0, 2);
    lcd.print("  MAIN SUPPLY: OFF  ");
    lcd.setCursor(0, 3);
    lcd.print("  UPS  : ON  ");
  }
  else  {
    digitalWrite(Ups_Start, LOW);
    digitalWrite(Ups_Relay, LOW);
    digitalWrite(Main_Relay, HIGH);

    lcd.setCursor(0, 2);
    lcd.print("  MAIN SUPPLY: ON  ");
    lcd.setCursor(0, 3);
    lcd.print("  UPS  : OFF  ");
  }
  potinputval = analogRead(potinput);
  feedbackinputval = analogRead(feedbackinput);
  while (feedbackinputval < potinputval  ) {
    if (A >= max_power) {
      potinputval = analogRead(potinput);
      feedbackinputval = analogRead(feedbackinput);
    }
    else {
      A = A + 1;
      potinputval = analogRead(potinput);
      feedbackinputval = analogRead(feedbackinput);
    }
  }
  lcd.setCursor(17, 3);    //For debug
  lcd.print(sensorValue);  //For debug
  while (feedbackinputval > potinputval ) {
    if (A == 0) {
      potinputval = analogRead(potinput);
      feedbackinputval = analogRead(feedbackinput);
    }
    else {
      A = A - 1;
      potinputval = analogRead(potinput);
      feedbackinputval = analogRead(feedbackinput);
    }
  }
}
//----------------------------------------------------------
void generate_sinus() {
  generate();
}
//----------------------------------------------------------
void generate() {
  if (sample >= total_sample && flag == 1  ) {
    flag = 0;
    sample = 1;
    //TCCR1A=0b10100000;
  }
  if (sample >= total_sample && flag == 0) {
    flag = 1;
    sample = 1;
    //TCCR1A=0b10100000;;
  }
  sample++;
  if (flag == 0) {
    Timer1.pwm(outA, (sinus[sample]* A));
    //PORTB=(0<<PORTB3);
    Timer1.pwm(outB, 0);
  }
  if (flag == 1) {
    Timer1.pwm(outA, 0);
    //PORTB=(1<<PORTB3);
    Timer1.pwm(outB, (sinus[sample]* A));
  }
}