/* CodeSchoss
 *
 * Benutzt den Drehimpulsgeber und die LCD
 *
 * LCD-Anschluesse:
 * LCD RS pin to digital pin 12
 * LCD Enable pin to digital pin 11
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 0 (STATT 2 !!!)
 * LCD R/W pin to ground
 * 
 * Encoder auf Pin 8 (Taster), 9 und 10
 */

#include <LiquidCrystal.h>
#include <Encoder.h>

const int Taster = 8;         // Pin für den Taster
const int Led = 13;           // Pin für LED

Encoder myEnc(9, 10);
LiquidCrystal lcd(12, 11, 5, 4, 3, 0);

char Code[]    = "DM8MB";     // geheimer Schlüssel
char Eingabe[] = "AAAAA";     // (falsche) Vorgabe gleicher Länge
int  Length = sizeof(Code)-1; // Länge des Schlüssels

int  buttonState;             // the current reading from the input pin
int  lastButtonState = LOW;   // the previous reading from the input pin
int  Pos = 0;                 // Position auf dem LCD/in der Eingabe
char c;

// the following variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long lastDebounceTime = 0;    // the last time the output pin was toggled
long debounceDelay = 50;      // the debounce time; increase if the output flickers

void setup() {
  lcd.begin(16, 2);           // set up the LCD's number of columns and rows
  pinMode (Taster, INPUT_PULLUP);
  pinMode (Led, OUTPUT);
  lcd.print (Code);           // macht den Test einfacher
  lcd.setCursor(0, 1);        // erstes Zeichen, zweite Zeile
  lcd.print (Eingabe);
  c = Eingabe[Pos];
  lcd.setCursor(Pos, 1);
  lcd.cursor();
}

long oldPosition  = -999;     // Initialwert Drehgeber

void loop() {
  int Oeffner = (!strncmp (Eingabe, Code, Length));
  digitalWrite(Led, Oeffner); // Status des Schlosses ausgeben

  int reading = digitalRead (Taster);
  
  if (reading != lastButtonState) {
    lastDebounceTime = millis();      // reset the debouncing timer
  } 
  
  if ((millis() - lastDebounceTime) > debounceDelay) {
    // whatever the reading is at, it's been there for longer
    // than the debounce delay, so take it as the actual current state:
    buttonState = reading;
  }

  if ((reading == LOW) && (reading != lastButtonState)) { // Button gedrückt
    Eingabe[Pos] = c;         // Eingabe verändern
    Pos = (Pos+1) % Length;   // Position weiterschalten
    c = Eingabe[Pos];         // nächstes Zeichen lesen
    lcd.setCursor(Pos, 1);    // Cursor neu positionieren
  }
  lastButtonState = reading;
  
  long newPosition = myEnc.read() >> 2;
  if (newPosition != oldPosition) {  // Buchstaben verändern im Bereich 0x30-0x5f
    c = c + newPosition - oldPosition;
    if (c > 0x5f) { c = c - 0x30;}
    if (c < 0x30) { c = c + 0x30;}
    lcd.print (c);            // geänderten Buchstaben anzeigen
    lcd.setCursor(Pos, 1);    // aber Cursor-Position beibehalten
    oldPosition = newPosition;
  }
}