#define  SEG_A  6
#define  SEG_B  7
#define  SEG_C  8
#define  SEG_D  9
#define  SEG_E  10
#define  SEG_F  11
#define  SEG_G  12
#define  SEG_DP  5
#define  DISP_1  2
#define  DISP_2  4

uint8_t  cnt = 0;
uint8_t  target = 0;

uint8_t  step_map[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 };

void setup()
{
  pinMode(SEG_A, OUTPUT);
  pinMode(SEG_B, OUTPUT);
  pinMode(SEG_C, OUTPUT);
  pinMode(SEG_D, OUTPUT);
  pinMode(SEG_E, OUTPUT);
  pinMode(SEG_F, OUTPUT);
  pinMode(SEG_G, OUTPUT);
  pinMode(SEG_DP, OUTPUT);
  pinMode(DISP_1, OUTPUT);
  pinMode(DISP_2, OUTPUT);
}

void loop()
{
    uint8_t  data1 = step_map[(analogRead(5)/(1024/11))];    
    
    uint8_t  digi10 = data1 / 10;
    uint8_t  digi1  = data1 - (digi10 * 10);

    digitalWrite(DISP_1, LOW);
    digitalWrite(DISP_2, LOW);
    
    if(target == 0 ){    
      seven_seg_out( digi1 );
      digitalWrite(DISP_1, HIGH);
      digitalWrite(DISP_2, LOW);
      target = 1;
    } else {
      seven_seg_out( digi10 );
      digitalWrite(DISP_1, LOW);
      digitalWrite(DISP_2, HIGH);
      target = 0;
    }
 }

void seven_seg_out(uint8_t input)
{
    input = input & 0xf;
    switch(input){
      case  0:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,LOW);
        break;
      case  1:
        digitalWrite(SEG_A,LOW);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,LOW);
        digitalWrite(SEG_E,LOW);
        digitalWrite(SEG_F,LOW);
        digitalWrite(SEG_G,LOW);
        break;
      case  2:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,LOW);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,LOW);
        digitalWrite(SEG_G,HIGH);
        break;
      case  3:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,LOW);
        digitalWrite(SEG_F,LOW);
        digitalWrite(SEG_G,HIGH);
        break;
      case  4:
        digitalWrite(SEG_A,LOW);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,LOW);
        digitalWrite(SEG_E,LOW);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  5:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,LOW);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,LOW);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  6:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,LOW);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  7:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,LOW);
        digitalWrite(SEG_E,LOW);
        digitalWrite(SEG_F,LOW);
        digitalWrite(SEG_G,LOW);
        break;
      case  8:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  9:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,LOW);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  10:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,LOW);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  11:
        digitalWrite(SEG_A,LOW);
        digitalWrite(SEG_B,LOW);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  12:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,LOW);
        digitalWrite(SEG_C,LOW);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,LOW);
        break;
      case  13:
        digitalWrite(SEG_A,LOW);
        digitalWrite(SEG_B,HIGH);
        digitalWrite(SEG_C,HIGH);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,LOW);
        digitalWrite(SEG_G,HIGH);
        break;
      case  14:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,LOW);
        digitalWrite(SEG_C,LOW);
        digitalWrite(SEG_D,HIGH);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      case  15:
        digitalWrite(SEG_A,HIGH);
        digitalWrite(SEG_B,LOW);
        digitalWrite(SEG_C,LOW);
        digitalWrite(SEG_D,LOW);
        digitalWrite(SEG_E,HIGH);
        digitalWrite(SEG_F,HIGH);
        digitalWrite(SEG_G,HIGH);
        break;
      default:
        break;
    }
}