Concerning the monitoring of the CO2 I’ll share an idea for displaying it.
Wanted to keep it all inside an outlet that could be used to power a solenoid connected to the CO2 tank. Due to space limitations I decided on using a little OLED… A place like OshPark can make you up a board SUPER inexpensive if you’re interested in such things. Anyhow, here are some pictures of the what I did to get the little OLED into the outlet.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.