Pimp your IKEA Vindriktning

(in harsh military voice)
This is my Ikea Vindriktning.
There are many like it, but this one is mine!

The Vindriktning is a 2.5 PPM particle counter meant to serve as an overall indication of interior air quality. It's pretty dumb and unpronounceable by western standards - it has 3 LED lights (green, orange and red), but for 14€ is an interesting device.
I learned that there's an UART and there's Tasmota support for it - although you need to compile your own and add a #define line.

So I thought - why not add this to emonCMS and HomeAssistant?

14€ and a few hours later, and I have a self contained, USB-C powered box, with,
a) PPM 2.5
b) Temperature, Humidity and atmospheric pressure - courtesy of Bosch BME280 sensor
c) Light sensor - via BH1750 which is i2c - pairs nicely with BME280 in parallel with no fussing around.

The light sensor is a breakout board without a diffusor - since the sensor is smart enough, I covered the LEDs and used their diffusor as a light diffusor.

Why? Today I automate my living room lighting via sunset hours - but what if it's raining and it's way darker sooner than sunset?
This light sensor can help with that, triggering lights if it falls below a given lux level for 10 minutes - and if the home theatre is turned on (if the 🐈 is home alone, he prefers darkness anyway🤷‍♂️)

It's a small box but mostly empty inside, and I believe there's still space for a CO2 sensor and TVOC (Total volatile organic compounds). I ordered a MH-Z19B which is more expensive than the whole box put together.
When it arrives from China I'll redo all cabling.

The whole project took less than 4 hours - if I ignore 2 days on and off searching for a CO2 sensor that's "good enough" without breaking the wallet - and was hell a lot of fun.

Now to tune HomeAssistant dashboards!