Posted on Leave a comment

Connecting a 7-Segment display to an Arduino

Certainly! Here’s a revised version of the tutorial that includes code for looping through multiple digits on a seven-segment LED display:

Materials Required

  • Arduino Uno
  • Breadboard
  • Seven-segment LED display (common cathode or common anode)
  • Jumper wires
  • USB cable (Type A to Type B)

Wiring the Circuit

Step 1: Place the Arduino Uno on the breadboard.

  • Position the Arduino Uno on the breadboard, aligning the USB port side with the longer section of the breadboard.

Step 2: Connect power and ground.

  • Connect the 5V pin of the Arduino to the positive rail (+) on the breadboard.
  • Connect the GND pin of the Arduino to the ground rail (-) on the breadboard.

Step 3: Connect the segment pins of the seven-segment LED display.

  • Identify the segment pins on your seven-segment LED display. The common cathode display will have a common cathode pin, while the common anode display will have a common anode pin.
  • Connect the segment pins of the seven-segment LED display to the Arduino Uno using jumper wires. Ensure that the pin connections match those specified in the code examples I provided earlier. For example, connect segment pin “a” to Arduino pin 2, segment pin “b” to Arduino pin 3, and so on.

Step 4: Connect the common pin of the seven-segment LED display.

  • For a common cathode display, connect the common cathode pin to the ground rail (-) on the breadboard.
  • For a common anode display, connect the common anode pin to the positive rail (+) on the breadboard.

Step 5: Load the code onto the Arduino Uno.

  • Open the Arduino Integrated Development Environment (IDE) on your computer. If you don’t have it installed, you can download it from the official Arduino website (
  • Connect the Arduino Uno to your computer using the USB cable.
  • In the Arduino IDE, select the appropriate board by navigating to “Tools” > “Board” > “Arduino Uno”.
  • Select the appropriate port by navigating to “Tools” > “Port” and selecting the port that corresponds to your Arduino Uno.
  • Copy and paste the following code into the Arduino IDE:

// Pin Definitions
const int segmentPins[] = {2, 3, 4, 5, 6, 7, 8}; // Pins connected to segments a, b, c, d, e, f, g
const int digitPins[] = {9, 10, 11, 12}; // Pins connected to digit 1, 2, 3, 4

// Digit patterns for numbers 0 to 9
const byte digitPatterns[] = {
B11111100, // 0
B01100000, // 1
B11011010, // 2
B11110010, // 3
B01100110, // 4
B10110110, // 5
B10111110, // 6
B11100000, // 7
B11111110, // 8
B11110110 // 9

void setup() {
// Set segment and digit pins as outputs
for (int i = 0; i < 7; i++) {
pinMode(segmentPins[i], OUTPUT);

for (int i = 0; i < 4; i++) {
pinMode(digitPins[i], OUTPUT
\void loop() {
  int number = 1234; // Number to display

  displayNumber(number); // Display the number
  delay(1000);           // Wait for 1 second

void displayNumber(int number) {
  // Extract individual digits from the number
  int digits[4];
  digits[0] = number / 1000;
  digits[1] = (number / 100) % 10;
  digits[2] = (number / 10) % 10;
  digits[3] = number % 10;

  // Loop through each digit
  for (int i = 0; i < 4; i++) {
    // Set the current digit pin high
    digitalWrite(digitPins[i], HIGH);

    // Display the digit pattern on the segments
    for (int j = 0; j < 7; j++) {
      digitalWrite(segmentPins[j], bitRead(digitPatterns[digits[i]], j));

    // Delay to hold the digit for a short period

    // Set the current digit pin low to turn it off
    digitalWrite(digitPins[i], LOW);

In this code, the loop() function continuously repeats the process of displaying the number on the seven-segment LED display and then waiting for 1 second before displaying the next number.

The displayNumber() function takes the number as input and extracts individual digits from it. It then iterates through each digit, sets the corresponding digit pin high to select it, and displays the digit pattern on the segments of the seven-segment LED display. After a short delay, the digit pin is set low to turn it off.

To customize the displayed number, modify the number variable in the loop() function.

After completing these steps, verify the wiring connections and click on the “Upload” button (right arrow icon) in the Arduino IDE to compile and upload the code to the Arduino Uno. The Arduino Uno will then run the code and display the desired numbers on the seven-segment LED display.

Remember to adjust the pin numbers in the code if you have connected the segments or digit pins to different Arduino pins.

That’s it! You have successfully wired an Arduino Uno with a seven-segment LED display using a breadboard and loaded the code to display multiple digits.

Posted on Leave a comment

Let’s Make a Raspberry Pi Display Digits on a Single 7-Segment LED with Python!


Hey there! So, you’ve got yourself a Raspberry Pi, huh? That’s awesome! In this tutorial, we’re going to have some fun and learn how to make that Raspberry Pi of yours display some cool digits on a nifty 7-segment LED. It’s going to be a great adventure in programming and tinkering with hardware, so let’s dive right in!

Step 1: Wiring the Raspberry Pi and 7-Segment LED Display

Okay, before we start making things light up, we need to do some wiring. Don’t worry, it’s easier than it sounds! Grab your Raspberry Pi, the 7-segment LED display, a breadboard, and some jumper wires. Here’s what you need to do:

  1. Connect the common cathode (or common anode) pin of the 7-segment display to a GND pin on your Raspberry Pi. This helps create a common reference for the LED segments.
  2. Take a deep breath and connect each segment pin of the display to individual GPIO pins on the Raspberry Pi. And hey, don’t forget to use resistors (around 220-470 Ohms) to keep things safe and sound.

Step 2: Setting up the Raspberry Pi

Now that our hardware is all set, let’s make sure our Raspberry Pi is ready to rock and roll. Make sure your Pi is powered on and connected to a monitor, keyboard, and mouse. Ready? Alright, here’s what you need to do:

  1. If you prefer using the Raspberry Pi’s built-in Python editor, you can access it by clicking on the Raspberry Pi icon in the top-left corner, navigating to Programming, and selecting “Thonny Python IDE.” This editor provides a user-friendly interface for writing and running Python code directly on the Pi.
  2. Alternatively, if you prefer using a common text editor on another computer, you can connect to your Raspberry Pi via SSH. Open a terminal on your computer and type ssh pi@<your_pi's_IP_address> (replace <your_pi's_IP_address> with the IP address of your Raspberry Pi). Enter the Pi’s password when prompted, and voila! You can now remotely edit and run Python code on your Pi using your favorite text editor.

Step 3: Writing and Running the Python Code

Here comes the fun part: writing the Python code to control our 7-segment LED display. Ready to get coding? Let’s do this!

  1. Open your preferred Python editor, either the built-in editor on the Raspberry Pi or a text editor on another computer connected via SSH.
  2. Create a new Python script. Let’s call it for simplicity.
  3. Import the necessary libraries at the top of your script. Add the following lines:
import RPi.GPIO as GPIO
import time
  1. Define the GPIO pins we’ll use for our LED segments. Add the following line:
# Define the segment pins
segments = (11, 12, 13, 15, 16, 18, 22, 7)
  1. Set up the GPIO mode and create a function that will display a digit on our 7-segment display. Use the following code snippet:
# Set up GPIO mode

# Set up GPIO pins as output
GPIO.setup(segments, GPIO.OUT)

# Define digit patterns for 0-9

 = {
    0: (1, 1, 1, 1, 1, 1, 0),
    1: (0, 1, 1, 0, 0, 0, 0),
    2: (1, 1, 0, 1, 1, 0, 1),
    3: (1, 1, 1, 1, 0, 0, 1),
    # Keep adding patterns for other digits...
  1. Write a function that will display a specific digit on our LED display. Here’s an example:
def display_digit(digit):
    for i in range(7):
        GPIO.output(segments[i], digits[digit][i])
  1. Save the Python script. To run the program, open a terminal on the Raspberry Pi (if you’re using the built-in editor) or on your computer (if you’re using SSH). Navigate to the directory where you saved the script, and type the following command:

This will execute the Python script, and you should see the digits being displayed on the 7-segment LED.


Congratulations! You’ve successfully learned how to wire up a 7-segment LED display to your Raspberry Pi, write Python code to control it, and run the program. Isn’t that amazing? Now you can display all sorts of digits and create your own digital masterpieces. Keep exploring and experimenting with your Raspberry Pi. The possibilities are endless!

Happy coding!