Last year I found a bulk of electronic components in the trash. Perfectly fine things such as these VQE displays. Who in his right mind does that!? Anyway, at the time I didn't really have a use for them (maybe for a future project like a clock in back to the future style).

So why not using them in a very cliché way - displaying temperature in Celsius using parts I already have lying around. But let me get this straight: It is by no means a project ready for manufacturing. It's in a way a working concept for my current needs.

The most convenient way was using two ATTiny4313 as I²C port expander and a Feather board as 'brain'. I use a 3Vish power supply for the displays, so I don't have to bother with resistors or constant current supplies for the displays. A battery, NTC thermistor and a photo transistor hooked up to the Feather board make this setup complete. Nothing too fancy. I had a lot of fun and it was a welcome change from the usual.