PiWatcher TB Is a Raspberry Pi Watchdog

A well-worth-the-buy Raspberry Pi peripheral device is now available on Tindie, Omzlo's PiWatcher TB, a small board made to automatically shut down or reboot your Pi when needed. Useful in case of incident or just for power saving purposes, the board can even be programmed to shut an Pi down and automatically reboot it a set amount of time later, whether that means a few minutes or a few hours.

Simply put, the PiWatcher TB is a watchdog circuit for the Raspberry Pi. It is a variation on Omzlo's classic PiWatcher also available on Tindie. It is designed to solve two problems with regard to power management on Pis: wasteful power usage due to incomplete shutdown following a shutdown or halt command and recovery from situations in which the Pi has become stuck in an unrecoverable state. For the first, the watchdog circuit can be configured to fully cut power following a shutdown command. For the second, it can be programmed to power cycle should it not read a heartbeat from the device after a set period of time.

Where the classic iteration has a USB connector, the TB has replaced it with a high-quality 2.54 mm pitch screw terminal block. The TB has the added feature of being able to connect to an external switch as well. The TB is a more specialized version of the watchdog already available, developed specifically for more industrial applications.

To serve its purpose, the board must be fitted on the first six pins of the Raspberry GPIO header and wired to a 5V power supply suitable for the Pi you're using. The PiWatcher receives instructions through I2C and can be instructed to reboot the Pi if it becomes irresponsive for a set period of time or to power off and reboot the Pi in set intervals, as might be necessary for recurring tasks. Manual control is also possible via a built-in miniature tact switch or by connecting an external switch.

This tiny watchdog board — with a price tag of under $10 — is open source and comes with a 2x3 female pin header and three-pin 2.54mm terminal block. Both of these components come unsoldered by default but can be soldered prior to shipping for a slightly higher cost. The Raspberry Pi you wish to attach it to will have to be all your own.