While you may not be familiar with the term “busy board”, you’ve almost certainly seen one. It’s the sort of toy with a bunch of buttons, switches, and of course LEDs, that are designed to keep young children entertained. As it so buttons, switches, buttons, and LEDs also keep hardware hackers entertained — doubly so if they are the ones designing said busy board in the first place.

That’s where we find [Andy], or should we say, [Uncle Andrew]. Last Christmas he decided to scratch build an electronic busy board for his nephew, and while it might not be a terribly complex piece of kit from a technical standpoint, it’s a fantastic multidisciplinary project in that it’s really equal parts hardware and software. While it would surely be possible to implement a gadget like this entirely in hardware, [Andy] took the modern hobbyist approach of offloading some of the task to a collection of carefully arranged ones and zeros.

In the write-up, [Andy] goes over the decisions he made while designing and building the device. This ranges from the extra effort put in to keep the PCB down to two layers and the logic behind LED multiplexing. This extends right into the software aspect of the project, with a surprisingly deep explanation of how the code uses timers and interrupts to run the show as efficiently as possible, maximizing the run time of the PIC18F67K40 microcontroller on a trio of AAA batteries.

It’s a fun read about a low-stakes project that’s made all the better by the personal touch. Just like the kids of makers and hardware hackers, [Andy]’s nephew is a lucky to have somebody like this in his life.