I’ve sketched a rough idea: a set of magnetic “snap‑in” blocks that fit into a soft, rubberized board. Each block has a tiny LED, a pull‑up resistor, and a low‑power microcontroller that flashes patterns when the child connects two blocks. The board runs on a 1.8 V coin cell, so it’s safe if they bite it or drop it. For gentle learning, the software uses colored lights and a voice that explains, “When you connect the red block to the blue block, the current flows and lights up the green block.” The whole thing is enclosed in a water‑resistant shell and uses no exposed wiring—just the magnetic contacts. Efficiency is baked in by shutting down unused blocks after a few seconds of inactivity, and the firmware is written in C with a minimalist RTOS so the 4 MHz processor can handle up to twenty blocks without stutter. The key is keeping the design modular so you can swap out a faulty block without opening the whole toy, and the safety features—low voltage, no small parts that could be swallowed, and a soft enclosure—make it compliant with toy standards. It’s simple, playful, and, if you’re into it, you can add a Bluetooth low‑energy port later to log progress.

Glad the plan hit the sweet spot. I’ll tighten up the magnet pull‑force and run a new LED current profile to nail that week‑plus battery life. Bluetooth logging is on the list—just gotta make sure the firmware stays under the 1.8 V budget. Thanks for the feedback; next iteration will have the “Bingo!” sound so the kids can brag about completing a circuit before breakfast.