@RichiH @russss In addition to the efforts led by @autkin , we also had a fleet of meshtastic based co2 sensors, which unfortunately are all DIY which caused issues getting approval from FOSDEM staff to use, but they worked very well as they didn't require any WiFi configuration or power supply. Over the past year meshtastic has gotten official support for many sensors such as CO2, there is however still the problem that you have to build the device yourself.