#include <Bounce2.h>
#define T1 11
#define T2 10
#define L2 12
#define L1 13

Bounce btn1 = Bounce();
Bounce btn2 = Bounce();
int e = 0;
int z = 0;


void setup() 
{
  Serial.begin(9600);
  btn1.attach(T1, INPUT_PULLUP);
  btn2.attach(T2, INPUT_PULLUP);
  btn1.interval(10);
  btn2.interval(10);
  pinMode(L1, OUTPUT);
  pinMode(L2, OUTPUT);
}

void eErkennen ()
{
  if (!btn2.read())
  {
    e = 2;
  }
  if(!btn1.read())
  {
    e = 1;
  }
  
}

void zustandsUebergang ()
{
  switch(e)
  {
    case 0:
    {
      z = 0;
      break;
    }
    case 1:
    {
      z = 1;
      break;
    }
    case 2: 
    {
      if (z == 2)
      {
        z = 1;
      }
      else
      {
        z = 2;
      }
      break;
    }
  }
}

void zAuswerten ()
{
  if (z == 1)
  {
    digitalWrite(L1, HIGH);
    digitalWrite(L2, LOW);
  }
  if (z == 2)
  {
    digitalWrite(L2, HIGH);
    digitalWrite(L1, LOW);
  }
  else
  {
    digitalWrite(L1, LOW);
    digitalWrite(L2, LOW);
  }
}

void loop() 
{
  btn1.update();
  btn2.update();
  eErkennen();
  zustandsUebergang();
  zAuswerten();
  Serial.println(z);
}