I’d like to find a Air Quality monitor for around $50 if possible that does PM2.5 but possibly PM1.0 and PM10 detection, realtime but allows you to see trends over time, has wifi/bluetooth connectivity and a decent iPhone app.
Make your own, I have and whilst it’s worked out a bit more than $50 a unit as I had to buy 5 PCBs building some more was easy enough to do.
There is no phone app but if you run Home Assistant you can use that as an app/tracker and configure your own displays.
Bit of soldering and ordering some bits from Aliexpress but nothing too taxing and the 3 I’m currently running are giving me some good data.
https://www.printables.com/refresh?redirectUrl=%2Fmodel%2F1079858-3d-printer-emission-sensor-array-sensorbox-v2