How to Set Up a Watchdog Timer on Raspberry Pi


If you're working on Raspberry Pi projects, ensuring system reliability is crucial. A watchdog timer is a vital tool for achieving this. It helps prevent system freezes and crashes by resetting the system if it becomes unresponsive. This guide will walk you through setting up a watchdog timer on your Raspberry Pi.

What is a Watchdog Timer?

A watchdog timer (WDT) is a hardware or software timer that triggers a system reset if the main program, due to some fault or loop, fails to reset the timer within a preset time. It's like a guardian that restarts the system if it stops working correctly.


  • A Raspberry Pi (any model)
  • Latest version of Raspberry Pi OS installed
  • Basic familiarity with the command line interface

Step-by-Step Guide

Step 1: Update Your Raspberry Pi

First, ensure your Raspberry Pi is up to date. Open the terminal and type:

sudo apt update
sudo apt upgrade

Step 2: Enable the Watchdog Timer

The Raspberry Pi comes with a built-in hardware watchdog timer. To enable it, you need to edit the /boot/config.txt file. Type:

sudo nano /boot/config.txt

Add the following line at the end of the file:


Save and exit by pressing CTRL+X, then Y, and Enter.

Step 3: Install the Watchdog Daemon

Install the watchdog daemon, a software that uses the hardware watchdog timer:

sudo apt install watchdog

Step 4: Configure the Watchdog Daemon

Edit the watchdog configuration file:

sudo nano /etc/watchdog.conf

Uncomment (remove the # at the beginning) or add these lines:

watchdog-device = /dev/watchdog
max-load-1 = 24

The max-load-1 is the load average at which the watchdog will reset the system. You can adjust this value based on your needs.

Step 5: Activate the Watchdog

Enable and start the watchdog service:

sudo systemctl enable watchdog
sudo systemctl start watchdog

Step 6: Testing the Watchdog

To test if the watchdog is working, you can force a system freeze. This step is optional and should be done with caution:

sudo fork bomb

This command will overwhelm the system, causing the watchdog to reset the Raspberry Pi.


Setting up a watchdog timer on your Raspberry Pi enhances its reliability, especially for critical or long-running projects. By following these steps, you can ensure your system remains operational even in the event of software issues.

Remember, the watchdog timer is a safety net, not a substitute for proper system maintenance and monitoring. Regularly check and update your Raspberry Pi to keep it running smoothly.

Happy tinkering!