# Background After reading about the impact of CO2 levels on cognition, I created a simple prototype of a CO2 monitor and level indicator. It also reports readings to a mobile phone using Bluetooth LE. I posted this a few years later on hackster.io. [See the project on hackster.io](https://www.hackster.io/breakpointer/air-impaired-b3b4ea) This prototype is still functioning very well, now many years old. There have been a few iterations since. # Parts Here are the parts. Everything is from Adafruit except the K-30 CO2 sensor from [CO2meter.com](http://CO2meter.com). ![co2proto parts](./co2proto_parts.jpg) The K-30 CO2 sensor. It speaks serial and I2C. I think it also has analog outputs too. ![co2proto k30 sensor](./co2proto_k30_sensor.jpg) # Assembly First test of the sensor streaming the CO2 level readings to an Android app over Bluetooth. ![co2proto breadboard w bt](./co2proto_breadboard_w_bt.jpg) Hand-modified enclosure (electric drill, X-Acto knife, and wood file). The parts almost fit exactly. ![co2proto front enclosure](./co2proto_front_enclosure.jpg) As always, liberal use of hot glue. ![co2proto k30 ledbar mounted](./co2proto_k30_ledbar_mounted.jpg) ![co2proto inside final assembly](./co2proto_inside_final_assembly.jpg) ![co2proto mounted parts](./co2proto_mounted_parts.jpg) ![co2proto perfboard closeup](./co2proto_perfboard_closeup.jpg) ![co2proto perfboard mounted](./co2proto_perfboard_mounted.jpg) It's important to test things before you start assembling. #lifelesson ![co2proto pre assembly test](./co2proto_pre_assembly_test.jpg) The most basic enclosure possible. Not pretty, but it gets the job done. The gap in the back is because the parts are actually too deep to fasten the screws on the back plate. At home I use a rubber band to keep it from falling off. It makes it look like it has a headband. lol. ![co2proto final assembly](./co2proto_final_assembly.jpg) ![co2proto first assembly test](./co2proto_first_assembly_test.jpg) # Enclosure Concepts I came up with a few other design concepts for the enclosure. Here are some models and sketches. ![co2proto concept1 sketch](./co2proto_concept1_sketch.jpg) ![co2proto concept1 clay](./co2proto_concept1_clay.jpg) ![co2proto concept2 sketch](./co2proto_concept2_sketch.jpg) ![co2proto concept2 clay](./co2proto_concept2_clay.jpg)

CO2 Monitoring Device Enclosure by breakpointer on Sketchfab

Once I got into Fusion 360, this is what I designed. I think it looks like a dial-up modem from the 90s. Much better than the original enclosure though. ![co2proto concept3 actual](./co2proto_concept3_actual.jpg) You can buy my design here on [Sculpteo](https://www.sculpteo.com/en/print_new/co2_btle_enclosure/vj8RfEkK).

Air Impaired