Arduino Uno 7-Segment Display

Breadboard Setup

Circuit Schematics

Implementation…

/*
Control a group of 8x LEDs using a 74HC595 Shift Register

  - Pin 1-7,15 output to LEDs + 220ohm resistors
  - Pin 8  == GND connect to ground
  - Pin 10 == MR, Master Reclear, connect to 5V
  - Pin 13 == OE, Output enable, connect to ground
  - Pin 16 == VCC connect to 5V
*/

const int msec = 1000;
// Output pins connected to the 74HC595 shift register
const int dPin = 4; // goes to pin 14 == DS, Serial data input 
const int lPin = 5; // goes to pin 12 == ST_CP, Storage register clock pin (latch pin)
const int cPin = 6; // goes to pin 11 == SH_CP, Shift register clock pin

unsigned int num[] = { 
  0b11111100, // 0
  0b01100000, // 1
  0b11011010, // 2
  0b11110010, // 3 
  0b01100110, // 4
  0b10110110, // 5
  0b10111110, // 6
  0b11100000, // 7
  0b11111110, // 8
  0b11100110, // 9
  0b11101110, // A
  0b00111110, // b
  0b10011100, // C
  0b01111010, // d
  0b10011110, // E
  0b10001110, // F
  0b00000001  // DP
};
// Represents the state of the shift register chip 
// Pins 1-7,15 == Q0-Q7, Output Pins
byte leds = 0;

// Print bit representation of a byte
void serialPrintByte(byte b) {
  byte i;
  // loop bit shift
  for (byte i = 0; i < 8; i++) {
    Serial.print(b >> i & 1, BIN);
  }
  Serial.println("");
}

void txRegisterState(byte state) {
  // Signal the register to read from the data pin
  digitalWrite(lPin, LOW);
  Serial.println("Ground latch pin while transmitting data");
  // Use the data pin to send a byte to the register bit-by-bit
  //   - Right most LSB (Least Significant Bit)
  shiftOut(dPin, cPin, LSBFIRST, state);
  // Signal the register to set all its output pins
  digitalWrite(lPin, HIGH);
  Serial.print("LEDs bit state: ");
  serialPrintByte(state);
  Serial.println("Signal end of transmission");
}


void setup() {
  Serial.begin(9600);
  pinMode(dPin, OUTPUT);
  pinMode(lPin,OUTPUT);
  pinMode(cPin,OUTPUT);
}

void loop() {
  int n;
  for(n = 0; n <= 17; n++) 
  { 
    txRegisterState(num[n]);
    delay(msec);
  }
}