1. 7-segment display - HDSM-431W (D1)
2. Microcontroller (e.g., Arduino)
3. Current limiting resistors for each segment
4. Common connections for the 7-segment display

• a: Pin 7
• b: Pin 6
• c: Pin 4
• d: Pin 2
• e: Pin 1
• f: Pin 9
• g: Pin 10
• dp: Pin 5
• CA (Common Anode): Pin 8

• D1:7 (a) to Arduino digital pin (e.g., 2) through a resistor.
• D1:6 (b) to Arduino digital pin (e.g., 3) through a resistor.
• D1:4 (c) to Arduino digital pin (e.g., 4) through a resistor.
• D1:2 (d) to Arduino digital pin (e.g., 5) through a resistor.
• D1:1 (e) to Arduino digital pin (e.g., 6) through a resistor.
• D1:9 (f) to Arduino digital pin (e.g., 7) through a resistor.
• D1:10 (g) to Arduino digital pin (e.g., 8) through a resistor.
• D1:5 (dp) to Arduino digital pin (e.g., 9) through a resistor.
• D1:8 (CA) to Vcc (5V).

Cpp
const int segmentPins[8] = {2, 3, 4, 5, 6, 7, 8, 9}; // Define the pins connected to the segments a, b, c, d, e, f, g, dp
const byte numbers[10] = {
    0b00111111, // 0
    0b00000110, // 1
    0b01011011, // 2
    0b01001111, // 3
    0b01100110, // 4
    0b01101101, // 5
    0b01111101, // 6
    0b00000111, // 7
    0b01111111, // 8
    0b01101111  // 9
};

void setup() {
    for (int i = 0; i < 8; i++) {
        pinMode(segmentPins[i], OUTPUT);
    }
}

void displayDigit(int digit) {
    for (int i = 0; i < 8; i++) {
        digitalWrite(segmentPins[i], bitRead(numbers[digit], i));
    }
}

void loop() {
    for (int i = 0; i <= 9; i++) {
        displayDigit(i);
        delay(1000); // Display each digit for 1 second
    }
}

• segmentPins[] defines the digital pins connected to each segment (a-g, dp).
• numbers[] holds the binary representation of each number (0-9) for the 7-segment display.
• In setup(), all segment pins are set to OUTPUT.
• displayDigit() activates the correct segments to display a given digit.
• loop() counts from 0 to 9, displaying each number for 1 second.