We have all at some level in our life opened the fridge doorway and promptly wished we hadn’t. A miasma of stench envelops us as we learn that previous Saturday’s leftovers have been forgotten, and have absent off. If only we had some way to retain observe of such matters, to steer clear of these a stench-laden second. Action ahead [ThinkLearnDo], with a minor timer designed for accurately that purpose.
The operation is uncomplicated adequate, push the button and position the unit on top rated of the container with the leftovers in it. If you have not eaten the leftovers within just a week, the LED will start blinking. The blink is a subtle reminder to deal with the outdated foodstuff before it gets to be a difficulty.
Onboard is a Holtek HT68F001 microcontroller with a coin cell for electricity, not much else is required. The Holtek is an uncommon selection, one particular of various brand names of super-cheap Chinese microcontrollers we see significantly less usually than ATmegas and STM32s. This is accurately the spot exactly where this sort of a minimum computer matches completely: a way to add a tiny bit of smarts to a pretty low cost product with minimum pressure on the BoM.
If these chips curiosity you, a although again we included a run-down of the distinctive family members like the Holtek and the famous 3-cent Padauk chips.