#include <Arduino.h>

const int analogInPin = A3;  // Analog input pin that the potentiometer is attached to

int sensorValue = 0;        // value read from the pot
int outputValue = 0;        // value output to the PWM (analog out)

int k1;
int k2;
int k3;



#define LED 3
#define KEY A2

int KEY_NUM = 0;      





#define SEG_A 8
#define SEG_B 4
#define SEG_C 14
#define SEG_D 16
#define SEG_E 10
#define SEG_F 7
#define SEG_G 15
#define SEG_H A1

#define COM1 9
#define COM2 6
#define COM3 5
#define COM4 A0


unsigned char table[11][8] =
{
// h   g   f   e   d   c   b   a
  {0, 0,  1,  1,  1,  1,  1,  1},     //0
  {0, 0,  0,  0,  0,  1,  1,  0},     //1
  {0, 1,  0,  1,  1,  0,  1,  1},     //2
  {0, 1,  0,  0,  1,  1,  1,  1},     //3
  {0, 1,  1,  0,  0,  1,  1,  0},     //4
  {0, 1,  1,  0,  1,  1,  0,  1},     //5
  {0, 1,  1,  1,  1,  1,  0,  1},     //6
  {0, 0,  0,  0,  0,  1,  1,  1},     //7
  {0, 1,  1,  1,  1,  1,  1,  1},     //8
  {0, 1,  1,  0,  1,  1,  1,  1},     //9
  {0, 0,  1,  1,  1,  0,  0,  1}      //C
};

void setup()
{

    pinMode(LED,OUTPUT);          
  pinMode(KEY,INPUT_PULLUP);   

    Serial.begin(9600);
    
  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_H,OUTPUT);

  pinMode(COM1,OUTPUT);
  pinMode(COM2,OUTPUT);
  pinMode(COM3,OUTPUT);
  pinMode(COM4,OUTPUT);
}

void loop()
{
  // read the analog in value:
  sensorValue = analogRead(analogInPin);
  // map it to the range of the analog out:
  outputValue = map(sensorValue, 0, 1023, 0, 255);
  // change the analog out value:

  ScanKey();            
  if(KEY_NUM == 1)              
  {   
    digitalWrite(LED,HIGH);   
    delay(200);
    digitalWrite(LED,LOW);    
  }

  

  k1 = outputValue % 10;
  k2 = ((outputValue -k1)/10) %10;
  k3 = ((outputValue -k1-k2*10)/100) %10;

  
  // print the results to the Serial Monitor:
  Serial.print("sensor = ");
  Serial.print(sensorValue);
  Serial.print("\t output = ");
  Serial.println(outputValue);

  // wait 2 milliseconds before the next loop for the analog-to-digital
  // converter to settle after the last reading:
  delay(2);
  
  Display(1,10);      
  delay(3);
  Display(2,k3);      
  delay(3);
  Display(3,k2);      
  delay(3);
  Display(4,k1);      
  delay(3);
}

void Display(unsigned char com,unsigned char num)     
{
  digitalWrite(SEG_A,LOW);     
  digitalWrite(SEG_B,LOW);
  digitalWrite(SEG_C,LOW);
  digitalWrite(SEG_D,LOW);
  digitalWrite(SEG_E,LOW);
  digitalWrite(SEG_F,LOW);
  digitalWrite(SEG_G,LOW);
  digitalWrite(SEG_H,LOW);

  switch(com)          
  {
    case 1:
      digitalWrite(COM1,LOW);   
      digitalWrite(COM2,HIGH);
      digitalWrite(COM3,HIGH);
      digitalWrite(COM4,HIGH);
      break;
    case 2:
      digitalWrite(COM1,HIGH);
      digitalWrite(COM2,LOW);   
      digitalWrite(COM3,HIGH);
      digitalWrite(COM4,HIGH);
      break;
    case 3:
      digitalWrite(COM1,HIGH);
      digitalWrite(COM2,HIGH);
      digitalWrite(COM3,LOW);   
      digitalWrite(COM4,HIGH);
      break;
    case 4:
      digitalWrite(COM1,HIGH);
      digitalWrite(COM2,HIGH);
      digitalWrite(COM3,HIGH);
      digitalWrite(COM4,LOW);   
      break;
    default:break;
  }

  digitalWrite(SEG_A,table[num][7]);      
  digitalWrite(SEG_B,table[num][6]);
  digitalWrite(SEG_C,table[num][5]);
  digitalWrite(SEG_D,table[num][4]);
  digitalWrite(SEG_E,table[num][3]);
  digitalWrite(SEG_F,table[num][2]);
  digitalWrite(SEG_G,table[num][1]);
  digitalWrite(SEG_H,table[num][0]);
}



void ScanKey()           
{
  KEY_NUM = 0;            
  if(digitalRead(KEY) == LOW)    
  {
    delay(20);         
    if(digitalRead(KEY) == LOW)  
    {
      KEY_NUM = 1;      
      while(digitalRead(KEY) == LOW);
    }
  }
}