#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>

#define OLED_ADDR   0x3C
Adafruit_SSD1306 display(-1);

int settemp = 590; //manual set variables

int output = 0;
int temp = 0;
String inputString = "";
boolean rap = false;
boolean stringComplete = false;
int t = 0;
int mappedpower = 0;
byte powermultiply = 0;
long counter = 0;
int temp2 = 0;
byte outputoffset = 0;
byte scaleread = 0;

void setup() {
  Serial.begin(9600);
  pinMode(12, OUTPUT);
  digitalWrite(12, LOW);
  display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
  display.clearDisplay();
  display.display();
  rapid();
}

void loop() {
  pid();
  display.clearDisplay();
  updatebar();
  updatetext();
  display.display();
}

void rapid() { //Controls the soldering iron by rapidly heating it up in the beginning.
  if (rap == false) {
    digitalWrite(12, HIGH);
    output = 255;
    do {
      temp = analogRead(0);
      Serial.print("rapid");
      Serial.println(temp);
      display.clearDisplay();
      updatebar();
      updatetext();
      display.display();
    } while (temp - settemp > 1);
    digitalWrite(12, LOW);
    rap = true;
  }
}

void pid() { //Controls the soldering with slow active power heating.
  temp = analogRead(0);  //Temp averager
  temp2 = temp;
  delay(50);
  temp = analogRead(0);
  temp = temp + temp2;
  temp = temp / 2;

  zeroscale; //activate no soldering iron checker
  temp = temp + outputoffset;

  output = temp - settemp;
  output = output + powermultiply;
  output = output * 4;

  if (output < 0) {
    output = 0;
  }
  if (output > 255) {
    output = 255;
  }
  counter = counter + 1;
  if (counter > 10) {
    counter = 0;
    if (temp > settemp + 3) {
      powermultiply = powermultiply + 1;
    }
    if (temp < settemp - 3 && powermultiply > 0) {
      powermultiply = powermultiply - 1;
    }
  }
  Serial.print(powermultiply);
  Serial.print(", ");
  Serial.print(temp);
  Serial.print(", ");
  Serial.println(output);
  analogWrite(12, output);
}

void updatebar() { //Updates Powerbar on OLED display
  mappedpower = map(output, 0, 255, 0, 127) - 10;
  display.fillRect(0, 0, mappedpower, 8, WHITE);
  display.fillRoundRect(mappedpower - 5, 0, 20, 8, 3, WHITE);
}

void updatetext() {//Update text on Oled display
  display.setCursor(0, 9);
  display.setTextColor(WHITE);
  display.setTextSize(1);
  display.print("Set Temp: ");
  display.print(settemp);
  display.setCursor(0, 20);
  display.print("Temp: ");
  display.print(temp);
}

void zeroscale() { //If soldering iron is unplugged, adjust the input pin value to zero it out
  if (output < 200) {
    display.clearDisplay();

    display.setCursor(0, 9);
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.print("No soldering iron, or defective");
    display.setCursor(0, 15);
    display.print("iron.");
    display.setCursor(0, 20);
    display.print("Testing in 5 seconds.");

    display.display();
    delay(5000);

    if (output < 200) {
      outputoffset = temp;
    }
    display.clearDisplay();

    display.setCursor(0, 9);
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.print("Output offset set.");
    display.setCursor(0, 20);
    display.print("Please plug in the iron.");

    display.display();
    do {
      scaleread = analogRead(0);
    } while (scaleread < 200);

  }
}