Multiple LED patterns in Raspberry Pi - Mini Project: Build & Apply

Multiple LED patterns

📖 Scenario: You have a Raspberry Pi connected to three LEDs on pins 17, 27, and 22. You want to create different light patterns to make the LEDs blink in fun ways.

🎯 Goal: Build a program that controls three LEDs to blink in two different patterns: first all LEDs blink together, then they blink one by one in a sequence.

📋 What You'll Learn

Use the gpiozero library to control LEDs

Create a list of LED objects for pins 17, 27, and 22

Write code to blink all LEDs together three times

Write code to blink LEDs one by one in sequence three times

Print messages to show which pattern is running

💡 Why This Matters

🌍 Real World

Controlling LEDs on a Raspberry Pi is a common way to learn about hardware programming and create visual signals or indicators.

💼 Career

Understanding how to control hardware components like LEDs is useful for jobs in embedded systems, IoT development, and electronics prototyping.

1

Set up LEDs on pins 17, 27, and 22

Import LED from gpiozero and create a list called leds with three LEDs on pins 17, 27, and 22.

Raspberry Pi

from gpiozero import LED

# Create a list called leds with LEDs on pins 17, 27, and 22
# Your code here

Need a hint?

Use LED(pin_number) to create each LED object and put them inside a list named leds.

2

Set blink count

Create a variable called blink_count and set it to 3 to control how many times the LEDs will blink.

Raspberry Pi

from gpiozero import LED

leds = [LED(17), LED(27), LED(22)]

# Set blink_count to 3
# Your code here

Need a hint?

This variable will help repeat the blink patterns the right number of times.

3

Write LED blink patterns

Write a for loop using blink_count to blink all LEDs together by turning them on, waiting 0.5 seconds, then turning them off and waiting 0.5 seconds. Then write another for loop to blink each LED one by one in sequence with the same timing.

Raspberry Pi

from gpiozero import LED

leds = [LED(17), LED(27), LED(22)]

blink_count = 3

# Blink all LEDs together blink_count times
# Then blink each LED one by one blink_count times
# Your code here

Need a hint?

Use nested loops: outer loop repeats the pattern, inner loop controls LEDs. Use time.sleep(0.5) to pause.

4

Print pattern messages

Add print statements before each pattern to show "Blinking all LEDs together" and "Blinking LEDs one by one". Then run the program to see the messages and LED patterns.

Raspberry Pi

from gpiozero import LED

leds = [LED(17), LED(27), LED(22)]

blink_count = 3

import time

# Print message before blinking all LEDs together
# Your code here
for _ in range(blink_count):
    for led in leds:
        led.on()
    time.sleep(0.5)
    for led in leds:
        led.off()
    time.sleep(0.5)

# Print message before blinking LEDs one by one
# Your code here
for _ in range(blink_count):
    for led in leds:
        led.on()
        time.sleep(0.5)
        led.off()
        time.sleep(0.5)

Need a hint?

Use print() before each pattern loop to show which pattern is running.