How to Control 2 Digits Seven Segment Display Counter using Arduino by Multiplexing
Materials:
- Arduino UNO
- 1 2-digit 7-segment display (I got a 50-piece LED display grab bag for better value (plus the fun factor!) the one I used was configured as shown)
- 2 Mini push-button switches
- 9 Resistors 100 Ohm
- 2 Resistors 10K Ohm
- 1 Solderless breadboard
- Jumper wires in assorted lengths
Code:
// Dual seven-segment LED Display
// 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_SEG 4
#define G 5
// 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] = { A, B, C, D, E, F_SEG, G };
// Segments that make each number
const byte numbers[10] = { 0b1000000, 0b1111001, 0b0100100, 0b0110000, 0b0011001, 0b0010010,
0b0000010, 0b1111000, 0b0000000, 0b0010000 };
void setup() {
pinMode(A, OUTPUT);
pinMode(B, OUTPUT);
pinMode(C, OUTPUT);
pinMode(D, OUTPUT);
pinMode(E, OUTPUT);
pinMode(F_SEG, OUTPUT);
pinMode(G, OUTPUT);
pinMode(CA1, OUTPUT);
pinMode(CA2, OUTPUT);
}
void loop() {
for (int digit1=0; digit1 < 10; digit1++) {
for (int digit2=0; digit2 < 10; digit2++) {
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);
}
}
Watch The Video on YouTube
 |
