// Relay / LED Setup
//
// D18 is the Opto Thyristor for the soft start thermistors/relays.
// D19 is the relay for the mains transformer.
// D5 is the Opto SCR for the B+ connection.
const int led = 2;
const int qty_rel = 3;
const int relay[] = {5,18,19};
const int power = 23;

// Power Button Setup
const int button_hold = 750; // Time you have to hold button for power on/off
bool power_on = false;
bool block = false;
bool power_switch = false;
int click;
long click_time;
int click_prev;

void setup() {
  // put your setup code here, to run once:
  for (int i=0; i<qty_rel; i++) {
    pinMode(relay[i], OUTPUT);
  }

  pinMode(power, INPUT_PULLUP);
  pinMode(led, OUTPUT);
  digitalWrite(led, HIGH);
  
  for(int j=0; j<qty_rel; j++) {
    digitalWrite(relay[j], HIGH);
  }
}

void loop() {
  power_button();
}

void power_button() {
  click = digitalRead(power);
  if(click == LOW && click_prev == HIGH && !block) {
    click_time = millis();
    block = true;
  } if(click == LOW && !power_switch && (millis()-click_time) > long(button_hold)) {
      if (!power_on) {
        power_up();
      } else {
        power_down();
      }
  } if(click == HIGH && click_prev == LOW) {
      block = false;
      power_switch = false;
  } click_prev = click;
}

void power_up() {
  digitalWrite(relay[0], LOW);
  delay(500);
  digitalWrite(relay[1], LOW);
  delay(500);
  digitalWrite(relay[2], LOW);
  power_on = true;
  power_switch = true;
}

void power_down() {
  digitalWrite(relay[0], HIGH);
  digitalWrite(relay[1], HIGH);
  digitalWrite(relay[2], HIGH);
  power_on = false;
  power_switch = true;
}