LED control patterns in Embedded C - Mini Project: Build & Apply

LED Control Patterns

📖 Scenario: You are programming a simple embedded system with 4 LEDs connected to a microcontroller. You want to create different light patterns by turning LEDs on and off in a sequence.

🎯 Goal: Build a program that controls 4 LEDs using an array to represent their states, then create a pattern that turns LEDs on one by one, and finally print the LED states to simulate the output.

📋 What You'll Learn

Create an array called leds with 4 elements initialized to 0 (off).

Create a variable called current_led to track which LED to turn on.

Write a loop that sets the current_led element in leds to 1 (on) and others to 0 (off).

Print the leds array states to show which LEDs are on or off.

💡 Why This Matters

🌍 Real World

Embedded systems often control LEDs to show status or alerts. Learning to manage LED patterns is a basic skill for hardware programming.

💼 Career

Embedded software developers and hardware engineers use similar code to control lights and indicators on devices.

1

Create the LED array

Create an integer array called leds with 4 elements, all initialized to 0 to represent LEDs turned off.

Embedded C

int leds[4] = {0, 0, 0, 0}; // Your code here

Need a hint?

Think of leds as a row of 4 light switches, all starting off.

2

Add a variable to track the current LED

Create an integer variable called current_led and set it to 0 to track which LED will be turned on.

Embedded C

int leds[4] = {0, 0, 0, 0};
int current_led = 0; // Your code here

Need a hint?

This variable will help you choose which LED to turn on.

3

Turn on the current LED and turn off others

Write a for loop with variable i from 0 to 3 that sets leds[i] to 1 if i equals current_led, otherwise sets it to 0.

Embedded C

int leds[4] = {0, 0, 0, 0};
int current_led = 0;
for (int i = 0; i < 4; i++) {
    // Your code here
}

Need a hint?

Use the if statement inside the loop to set the LED states.

4

Print the LED states

Write a for loop with variable i from 0 to 3 that prints the value of leds[i] followed by a space, then print a newline after the loop.

Embedded C

int leds[4] = {0, 0, 0, 0};
int current_led = 0;
for (int i = 0; i < 4; i++) {
    if (i == current_led) {
        leds[i] = 1;
    } else {
        leds[i] = 0;
    }
}
// Your code here

Need a hint?

Use printf inside the loop to show each LED state, then print a newline.