Nice device, but too playful for my needs. I'm still looking for a good sensor like Aranet but without the display and the vendor lock-in. Maybe if display is removed from this one it would work?
you can get a ESP32 and a CO2-Sensor, easiest would be to use a development kit like a m5-stickC and the Sensirion SCD41 and with some small arduino scripts you are good to go to send the data via WLAN or BLE for something like 70€. Can be even cheaper if you don't use a development kit but it makes things a lot easier and the small display helps with debugging.
You can cover it with some tape. :)
;) the thought was more about reduce energy consumption and cost
Aranet runs on e-ink, with silly low energy refresh rate. The two (or was it one? ages since I last checked) AA batteries last me well over two years.
As for vendor lock-in, the basic readings get broadcast over bluetooth advertisments, and you can establish connection to get all the data. I have couple of them working nicely with HomeAssistant.
The cost, yeah, I'd love it to be cheaper.