#define SSD_A 2
#define SSD_B 3
#define SSD_C 4
#define SSD_D 5
#define SSD_E 6
#define SSD_F 7
#define SSD_G 8

void setup() {
  // put your setup code here, to run once:
  pinMode(SSD_A, OUTPUT);
  pinMode(SSD_B, OUTPUT);
  pinMode(SSD_C, OUTPUT);
  pinMode(SSD_D, OUTPUT);
  pinMode(SSD_E, OUTPUT);
  pinMode(SSD_F, OUTPUT);
  pinMode(SSD_G, OUTPUT);
}

void loop() {
  int val = analogRead(0);

  if (val < 20) {
    showDigitOne();
  }
  if (val > 20) {
    showDigitTwO();
  }
}

void showDigitOne() {
  digitalWrite(SSD_A, LOW);
  digitalWrite(SSD_D, LOW);
  digitalWrite(SSD_E, LOW);
  digitalWrite(SSD_F, LOW);
  digitalWrite(SSD_G, LOW);
  digitalWrite(SSD_B, HIGH);
  digitalWrite(SSD_C, HIGH);
}

void showDigitTwO() {
  digitalWrite(SSD_C, LOW);
  digitalWrite(SSD_F, LOW);
  digitalWrite(SSD_A, HIGH);
  digitalWrite(SSD_B, HIGH);
  digitalWrite(SSD_D, HIGH);
  digitalWrite(SSD_E, HIGH);
  digitalWrite(SSD_G, HIGH);
}