Generating precise delays with timers in Embedded C - Mini Project: Build & Apply

Generating precise delays with timers

📖 Scenario: You are programming a microcontroller to control an LED. To make the LED blink at a precise interval, you need to create a delay using a hardware timer.

🎯 Goal: Build a program that sets up a timer to generate a precise delay of 1 second, then toggles an LED.

📋 What You'll Learn

Create a variable to hold the timer count value

Define a constant for the timer reload value for 1 second delay

Write a function to initialize the timer with the reload value

Write a loop that waits for the timer flag and toggles the LED

Print or output the LED state change (simulated)

💡 Why This Matters

🌍 Real World

Precise timing is essential in embedded systems to control hardware like LEDs, motors, or sensors accurately.

💼 Career

Embedded software engineers often write timer-based delays to manage hardware timing and synchronization.

1

Set up the timer count variable

Create an unsigned int variable called timer_count and set it to 0.

Embedded C

# Your code here

Need a hint?

Use unsigned int timer_count = 0; to create the variable.

2

Define the timer reload value

Define a constant #define TIMER_RELOAD 1000 to represent the timer reload value for a 1 second delay.

Embedded C

unsigned int timer_count = 0;
# Your code here

Need a hint?

Use #define TIMER_RELOAD 1000 to set the reload value.

3

Write the timer initialization function

Write a function called init_timer() that sets timer_count to TIMER_RELOAD.

Embedded C

unsigned int timer_count = 0;
#define TIMER_RELOAD 1000

// Your code here

Need a hint?

Define void init_timer() and inside set timer_count = TIMER_RELOAD;.

4

Create the main loop to wait and toggle LED

Write a main() function that calls init_timer(), then uses a while loop to decrement timer_count until it reaches 0, then prints "LED toggled" and resets timer_count to TIMER_RELOAD. Repeat this 3 times.

Embedded C

unsigned int timer_count = 0;
#define TIMER_RELOAD 1000

void init_timer() {
    timer_count = TIMER_RELOAD;
}

// Your code here

Need a hint?

Use nested loops: outer loop runs 3 times, inner loop decrements timer_count to 0, then print and reset.