$ cat aw4shift.ino
/*
AW4 Shift indicator
*/


void setup() {
//cheaping out on pins here.
//top and bottom share a pin
//upper right is always on.
  pinMode(0, OUTPUT);
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);

  pinMode(6, INPUT);    //1st sol
  pinMode(7, INPUT);    //2nd sol
  pinMode(8, INPUT);    //od sol

}

void char1() {
  digitalWrite(1, HIGH);
  digitalWrite(2, LOW);
  digitalWrite(3, LOW);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
}

void char2() {
  digitalWrite(1, LOW);
  digitalWrite(2, HIGH);
  digitalWrite(3, HIGH);
  digitalWrite(4, LOW);
  digitalWrite(5, HIGH);
}

void char3() {
  digitalWrite(1, HIGH);
  digitalWrite(2, HIGH);
  digitalWrite(3, HIGH);
  digitalWrite(4, LOW);
  digitalWrite(5, LOW);
}

void char4() {
  digitalWrite(1, HIGH);
  digitalWrite(2, LOW);
  digitalWrite(3, HIGH);
  digitalWrite(4, HIGH);
  digitalWrite(5, LOW);
}

void loop(){

  if (digitalRead(6) == HIGH) {
    if (digitalRead(7) == HIGH) {
      char2();
    } else {
      char1();
    }
  }else {
    if (digitalRead(7) == HIGH) {
      char3();
    } else {
      char4();
    }
  }
  if (digitalRead(8) == HIGH) {
    digitalWrite(0, HIGH);
  } else {
    digitalWrite(0, LOW);
  }
  delay(1);
}