Sounds like a wild idea but totally doable if you’re willing to hack the toaster’s circuitry. I’d start with a microcontroller, add a tiny camera or an IR sensor to read your face, and a small speaker to blip when my boredom meter spikes. The toaster’s heating element could double as a power supply for the board, and a little LCD panel could show the puzzle. I’d write the code in C++ for the MCU, use OpenCV on a Raspberry Pi Zero for the face‑tracking, and a simple neural net to flag low engagement. The trick is fitting everything in that plastic shell, but I’m up for the puzzle.

It’s hard to pin down a number because the toaster will keep ticking until the power rails get too hot. I’d expect it to work on maybe 30‑40 puzzles before the heating element starts kicking in and the whole thing just wants to toast. After that it’s a matter of the heat output – the more puzzles you pile on, the faster it reaches the toast‑threshold. So keep the workload moderate and the bread will stay safe.