int output = 0;
int temp = 0;
int settemp = 630;
String inputString = "";         // a string to hold incoming data
boolean rap = false;
boolean stringComplete = false;  // whether the string is complete
int t = 0;

void setup() {
  Serial.begin(9600);
  inputString.reserve(200);
  pinMode(6, OUTPUT);
  digitalWrite(6, LOW);
}

void loop() {
  serialEvent();
  if (stringComplete) {
    Serial.println(inputString);
    t = inputString.toInt();
    //settemp = t //sets the set temp to the serial input
    inputString = "";
    stringComplete = false;
  }
  rapid();
  pid();
}

void rapid() { //Controls the soldering iron by rapidly heating it up in the beginning.
  if (rap == false) {
    digitalWrite(6, HIGH);
    do {
      temp = analogRead(0);
      Serial.print("rapid");
      Serial.println(temp);
    } while (temp - settemp > 10);
    digitalWrite(6, LOW);
    rap = true;
  }
}

void pid() { //Controls the soldering with slow active power heating.
  temp = analogRead(0);
  output = temp - settemp;
  if (output < 0) {
    output = 0;
  }
  if (output > 255) {
    output = 255;
  }
  Serial.print("pid");
  Serial.print(temp);
  Serial.print(", ");
  Serial.println(output);
  analogWrite(6, output);
}

void serialEvent() {  //Serial communication that can be used to update settemp
  while (Serial.available()) {
    char inChar = (char)Serial.read();
    inputString += inChar;
    if (inChar == '\n') {
      stringComplete = true;
    }
  }
}