The Electronics Hobbyist

This week we modify the original circuit and sketch to include two buttons, one to control each digit of the display.

Here’s what the setup looks like:

And here’s the complete sketch:

// www.TheElectronicsHobbyist.com/blog
// Natalia Fargasch Norman
// Dual seven-segment LED Display with buttons
// Common Anode digit 1 pin 10
// Common Anode digit 2 pin 5

//       CA1 G  F  A  B
//        |  |  |  |  |      -> pins and segments they control
//   ---------    ---------
//   |   A   |    |   A   |
//  F|       |B  F|       |B
//   |---G---|    |---G---|
//  E|       |C  E|       |C
//   |   D   |    |   D   |
//   ---------    ---------
//        |  |  |  |  |      -> pins and segments they control
//        D  DP E  C CA2         

// Segments that make each number when lit:
// 0 => -FEDCBA
// 1 => ----BC-
// 2 => G-ED-BA
// 3 => G--DCBA
// 4 => GF--CB-
// 5 => GF-DC-A
// 6 => GFEDC-A
// 7 => ----CBA
// 8 => GFEDCBA
// 9 => GF-DCBA

// Arduino digital pins used to light up
// corresponding segments on the LED display
#define A 3
#define B 2
#define C 6
#define D 8
#define E 7
#define F 4
#define G 5

// Pushbuttons connected to pins 9 and 10
#define BTN1 9
#define BTN2 10

// Pins driving common anodes
#define CA1 13
#define CA2 12

// Pins for A B C D E F G, in sequence
const int segs[7] = { 3, 2, 6, 8, 7, 4, 5 };

// Segments that make each number
const byte numbers[10] = { 0b1000000, 0b1111001, 0b0100100, 0b0110000, 0b0011001, 0b0010010,
0b0000010, 0b1111000, 0b0000000, 0b0010000 };

int digit1 = 0;
int digit2 = 0;

void setup() {
  pinMode(A, OUTPUT);
  pinMode(B, OUTPUT);
  pinMode(C, OUTPUT);
  pinMode(D, OUTPUT);
  pinMode(E, OUTPUT);
  pinMode(F, OUTPUT);
  pinMode(G, OUTPUT);
  pinMode(BTN1, INPUT);
  pinMode(BTN2, INPUT);
  pinMode(CA1, OUTPUT);
  pinMode(CA2, OUTPUT);
}

void loop() {

  // check button1
  int val1 = digitalRead(BTN1);
  if (val1 == HIGH) {
    digit1++;
    digit1 %= 10;
    delay(10);
  }

  // check button2
  int val2 = digitalRead(BTN2);
  if (val2 == HIGH) {
    digit2++;
    digit2 %= 10;
    delay(10);
  }

  // display number
  unsigned long startTime = millis();
  for (unsigned long elapsed=0; elapsed < 600; elapsed = millis() - startTime) {
    lightDigit1(numbers[digit1]);
    delay(5);
    lightDigit2(numbers[digit2]);
    delay(5);
  }
}

void lightDigit1(byte number) {
  digitalWrite(CA1, LOW);
  digitalWrite(CA2, HIGH);
  lightSegments(number);
}

void lightDigit2(byte number) {
  digitalWrite(CA1, HIGH);
  digitalWrite(CA2, LOW);
  lightSegments(number);
}

void lightSegments(byte number) {
  for (int i = 0; i < 7; i++) {
    int bit = bitRead(number, i);
    digitalWrite(segs[i], bit);
  }
}

Here’s a video of the Arduino 2-digit 7-segment display counter with buttons in action.

You might also enjoy:

1. Arduino 2-Digit 7-Segment Display Counter
2. Arduino 2-Digit 7-Segment Display Counter: Sketch
3. Controlling a Seven-Segment Display Using Arduino Part 4
4. Controlling a Seven-Segment Display Using Arduino Part 3