#define segA 11
#define segB 10
#define segC 9
#define segD 8
#define segE 7
#define segF 6
#define segG 5
#define dig1 A3
#define dig2 A2
#define dig3 A1
#define dig4 A0
#define upButton 3
#define downButton 2

int cifras[4];
int count = 0;


void setup() {
  pinMode(segA, OUTPUT);
  pinMode(segB, OUTPUT);
  pinMode(segC, OUTPUT);
  pinMode(segD, OUTPUT);
  pinMode(segE, OUTPUT);
  pinMode(segF, OUTPUT);
  pinMode(segG, OUTPUT);
  
  pinMode(dig1, OUTPUT);
  pinMode(dig2, OUTPUT);
  pinMode(dig3, OUTPUT);
  pinMode(dig4, OUTPUT);

  pinMode(upButton, INPUT_PULLUP);
  pinMode(downButton, INPUT_PULLUP);

  cifras[0] = 0;
  cifras[1] = 0;
  cifras[2] = 0;
  cifras[3] = 0;
}

void loop() {
  test4();
}

void test1() {
  // Test #1: display 0 in digit 4, other digits are off
  //=======================================================
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, HIGH);

  digitalWrite(segA, LOW);
  digitalWrite(segB, LOW);
  digitalWrite(segC, LOW);
  digitalWrite(segD, LOW);
  digitalWrite(segE, LOW);
  digitalWrite(segF, LOW);
  digitalWrite(segG, HIGH);
}

void test2() {
  // Test #2: display 0000
  // =======================================================
  digitalWrite(segA, LOW);
  digitalWrite(segB, LOW);
  digitalWrite(segC, LOW);
  digitalWrite(segD, LOW);
  digitalWrite(segE, LOW);
  digitalWrite(segF, LOW);
  digitalWrite(segG, HIGH);

  digitalWrite(dig1, HIGH);
  digitalWrite(dig2, HIGH);
  digitalWrite(dig3, HIGH);
  digitalWrite(dig4, HIGH);  
} 

void test3() {
 // Test #3: display 1234
 // =======================================================
  setSegments(1);
  digitalWrite(dig1, HIGH);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, LOW);
  delay(10);

  setSegments(2);
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, HIGH);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, LOW);
  delay(10);
  
  setSegments(3);
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, HIGH);
  digitalWrite(dig4, LOW);
  delay(10);
  
  setSegments(4);
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, HIGH);
  delay(10);
}

void test4() {
// Test #4: display counting
// =======================================================
  setSegments(cifras[3]);
  digitalWrite(dig1, HIGH);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, LOW);
  delay(10);

  setSegments(cifras[2]);
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, HIGH);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, LOW);
  delay(10);
  
  setSegments(cifras[1]);
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, HIGH);
  digitalWrite(dig4, LOW);
  delay(10);
  
  setSegments(cifras[0]);
  digitalWrite(dig1, LOW);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, HIGH);
  delay(10);

  if (digitalRead(upButton)==LOW) {
    count++;
    if (count>9999) count = 9999;
  }
  if (digitalRead(downButton)==LOW) {
    count--;
    if (count<0) count=0;
  }  
  cifras[0] = count % 10;
  cifras[1] = (count/10) % 10;
  cifras[2] = (count/100) % 10;
  cifras[3] = (count/1000) % 10;
}

void setSegments(int number) {

  digitalWrite(dig1, LOW);
  digitalWrite(dig2, LOW);
  digitalWrite(dig3, LOW);
  digitalWrite(dig4, LOW);

  switch(number) {
    case 0: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, LOW);
      digitalWrite(segG, HIGH);
      break;

    case 1: 
      digitalWrite(segA, HIGH);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      break;

    case 2: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, LOW);
      digitalWrite(segC, HIGH);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, LOW);
      break;  

    case 3: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, LOW);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, LOW);
      break;

    case 4: 
      digitalWrite(segA, HIGH);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      break;

    case 5: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, LOW);
      digitalWrite(segD, LOW);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      break;

    case 6: 
      digitalWrite(segA, HIGH);
      digitalWrite(segB, HIGH);
      digitalWrite(segC, LOW);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      break;

    case 7: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, HIGH);
      digitalWrite(segG, HIGH);
      break;

    case 8: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, LOW);
      digitalWrite(segE, LOW);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      break;

    case 9: 
      digitalWrite(segA, LOW);
      digitalWrite(segB, LOW);
      digitalWrite(segC, LOW);
      digitalWrite(segD, HIGH);
      digitalWrite(segE, HIGH);
      digitalWrite(segF, LOW);
      digitalWrite(segG, LOW);
      break;
  }

}