What if I told you there was a pet inside your microcontroller? A watchdog (sometimes even two). Once you let it out of the kennel, you have to pet it regularly, or else it will bark. And you don't want that.

In the world of electronics, a watchdog is a security device that checks the status of a system. On most STM32 devices, there are two watchdogs: the IWDG and the WWDG. The WWDG is the Window Watchdog, a rather complex beast. The IWDG, called the Independent Watchdog, is a much simpler device; this is the one we will discuss.

As far as STM32 peripherals go, the IWDG is probably the simplest. Some have different functionalities, including the possibility to function in low power, watch multiple clock sources, or even work in window mode, but that is out of the scope of this article.