#define a 25
#define b 26
#define c 27
#define d 32
#define e 33
#define f 14
#define g 12

#define row1 23
#define row2 22
#define row3 21
#define col1 18
#define col2 17
#define col3 16

byte i=0;

void  setup() {
  pinMode(a, OUTPUT); //a
  pinMode(b, OUTPUT); //b
  pinMode(c, OUTPUT); //c
  pinMode(d, OUTPUT); //d
  pinMode(e, OUTPUT); //e
  pinMode(f, OUTPUT); //f
  pinMode(g, OUTPUT); //g
  pinMode(row1, OUTPUT); //Reihe 1
  pinMode(row2, OUTPUT); //Reihe 2
  pinMode(row3, OUTPUT); //Reihe 3
  pinMode(col1, INPUT);  //Spalte 1
  pinMode(col2, INPUT);  //Spalte 2
  pinMode(col3, INPUT);  //Spalte 3
  Serial.begin(9600);
 }

void loop() {
  digitalWrite(row1, HIGH);
  digitalWrite(row2, LOW);
  digitalWrite(row3, LOW);
  if(digitalRead(col1) == HIGH) i = 1;
  if(digitalRead(col2) == HIGH) i = 2;
  if(digitalRead(col3) == HIGH) i = 3;

  Serial.println(i);

  // ERGÄNZEN

  switch(i){
  case 1: digitalWrite(a, 0);
          digitalWrite(b, 1);
          digitalWrite(c, 1);
          digitalWrite(d, 0);
          digitalWrite(e, 0);
          digitalWrite(f, 0);
          digitalWrite(g, 0);
          break;
  case 2: digitalWrite(a, 1);
          digitalWrite(b, 1);
          digitalWrite(c, 0);
          digitalWrite(d, 1);
          digitalWrite(e, 1);
          digitalWrite(f, 0);
          digitalWrite(g, 1);
          break;
 
  }
}