/* 
DM6001 Assignment 1
Ruo Yi Chew (24163147)
*/

// inputs
#define INTERRUPT 2   // Red Button (EMO Button)
#define SYSTEM 3      // Green LED
#define CYCLE 6       // Yellow LED

// outputs
#define EMERGENCY 5   // Red LED (Emergency Light)
#define LIGHT 7       // Green LED
#define INTERLOCK 8   // Orange LED 1
#define MCU 10        // Orange LED 2
#define CLUTCH 11     // Yellow LED 1
#define STRIP_FEED 12 // Yellow LED 2
#define POWER 9       // used for power supply to the cycle

//variables
int onoff;            // used to test if power is on
int cyclepressed;     // used to test if cycle button is pressed

bool first_time = true;           // used to print emergency message ONCE
bool emergency_state = false;     // used to declare if it is emergency
bool is_on = false;

void setup() {
  Serial.begin(9600);               // start the Serial Monitor with baud rate 9600
  pinMode(INTERRUPT, INPUT);        // declare the inputs and outputs 
  pinMode(SYSTEM, INPUT);
  pinMode(CYCLE, INPUT);
  pinMode(POWER, OUTPUT);
  pinMode(EMERGENCY, OUTPUT);       
  pinMode(LIGHT, OUTPUT);
  pinMode(INTERLOCK, OUTPUT);
  pinMode(MCU,OUTPUT);
  pinMode(CLUTCH, OUTPUT);
  pinMode(STRIP_FEED, OUTPUT);
  //declare the interrupt under pin 2 with increasing button condition to trigger INTER() func
  attachInterrupt(digitalPinToInterrupt(INTERRUPT), INTER, RISING);   
}

void loop() {
  // check if the emergency state is true;
  if (emergency_state == true){
    EMO();
    return;
  }

  digitalWrite(POWER, HIGH);

  // Check the state of both buttons at the start of each loop
  onoff = digitalRead(SYSTEM);
  cyclepressed = digitalRead(CYCLE);
 
  // check if the start button is pressed
  if(onoff == 1)
  {
    if (is_on == false){            // if the system is not powered on
      StartUp();                    // Execute the startup sequence
    } else if (is_on == true){      // if the system is powered on
      ShutDown();                   // Excute shutdown sequence
    }
  }

  // now test if the cycle pressed button is high. 
  if(cyclepressed == 1){    
    Cycle();                        // Run the cycle
  } 
}                                   

// function to start up the system
void StartUp(){
  Serial.println("System On!");
  digitalWrite(LIGHT, HIGH);
  delay(500);
  digitalWrite(INTERLOCK, HIGH);
  digitalWrite(MCU, HIGH);
  // set a "system on" flag
  is_on = true;
}

// function to shut down the system
void ShutDown(){
  Serial.println("System Shut Down!");
  digitalWrite(LIGHT, LOW);
  delay(500);
  digitalWrite(INTERLOCK, LOW);
  digitalWrite( MCU, LOW);
  // set a "system off" flag;
  is_on = false;
}

// function to carry out the cycle
void Cycle(){
  if (is_on == true){                 // check that power is already on
    digitalWrite(CLUTCH, HIGH);       // carrying out a cycle
    delay(500);
    digitalWrite(CLUTCH, LOW);
    delay(500);
    digitalWrite(STRIP_FEED,HIGH);
    delay(500);
    digitalWrite(STRIP_FEED, LOW);
    delay(500);
  }
  digitalWrite(CYCLE, LOW);           // reset the Cycle Button
}

// interrupt function
void INTER(){
  if (is_on == true){   
    emergency_state = true;           // toggle the emergency state
  }
}

// function to carry out emergencyt procedures
void EMO(){
  if (first_time == true){                          // do this ONCE only
    for (int system = 7; system <= 12; system++){   // shut off the entire system
      digitalWrite(system, LOW);
    }
    Serial.println("EMERGENCY!!!!");    // print the emergency message
    is_on = false;                      // reset the entire system
    first_time = false;
  }
  digitalWrite(EMERGENCY, HIGH);        // blink the emergency LED
  delay(100);
  digitalWrite(EMERGENCY, LOW);
  delay(100);
}

// end of entire program.