Feeding (kicking) the watchdog in Embedded C - Mini Project: Build & Apply

Feeding (kicking) the watchdog

📖 Scenario: In embedded systems, a watchdog timer helps keep the system safe by resetting it if the program stops working properly. To prevent this reset, the program must regularly 'feed' or 'kick' the watchdog timer.Imagine you are programming a simple embedded device that needs to feed the watchdog every few seconds to keep running smoothly.

🎯 Goal: You will write a small embedded C program that sets up a watchdog timer and regularly feeds it inside a loop to prevent the system reset.

📋 What You'll Learn

Create a variable called watchdog_counter initialized to 0

Create a constant WATCHDOG_THRESHOLD set to 5

Use a while loop to simulate the program running

Inside the loop, increment watchdog_counter and feed the watchdog when it reaches the threshold

Print "Watchdog fed" each time the watchdog is fed

💡 Why This Matters

🌍 Real World

Watchdog timers are used in embedded devices like home appliances, cars, and medical devices to keep them running safely by resetting if the software hangs.

💼 Career

Understanding how to feed the watchdog is essential for embedded software engineers to ensure system reliability and prevent crashes.

1

Create the watchdog counter variable

Create an integer variable called watchdog_counter and set it to 0.

Embedded C

# Create an integer variable called watchdog_counter and set it to 0
# Your code here

Need a hint?

Use int watchdog_counter = 0; to create the variable.

2

Define the watchdog threshold

Create a constant integer called WATCHDOG_THRESHOLD and set it to 5.

Embedded C

int watchdog_counter = 0;
// Define a constant WATCHDOG_THRESHOLD with value 5
# Your code here

Need a hint?

Use const int WATCHDOG_THRESHOLD = 5; to define the threshold.

3

Implement the main loop and feeding logic

Write a while(1) loop. Inside it, increment watchdog_counter by 1. When watchdog_counter equals WATCHDOG_THRESHOLD, reset watchdog_counter to 0 and print "Watchdog fed".

Embedded C

int watchdog_counter = 0;
const int WATCHDOG_THRESHOLD = 5;

// Write a while(1) loop to increment watchdog_counter
// Feed the watchdog and reset counter when threshold is reached
# Your code here

Need a hint?

Use while(1) for an infinite loop. Increment the counter and check if it reached the threshold to feed the watchdog.

4

Run the program and observe output

Run the program and observe that it prints "Watchdog fed" repeatedly every 5 increments.

Embedded C

#include 

int watchdog_counter = 0;
const int WATCHDOG_THRESHOLD = 5;

int main() {
    while(1) {
        watchdog_counter++;
        if (watchdog_counter == WATCHDOG_THRESHOLD) {
            watchdog_counter = 0;
            printf("Watchdog fed\n");
        }
    }
    return 0;
}

// Run the program and observe output

Need a hint?

The program prints "Watchdog fed" every 5 increments. You may need to stop the infinite loop manually after seeing several lines.