Adding a CO2 relay for CO2 regulator controller


Instead of injecting CO2 via the yeast extractor I would like to utilize a CO2 tank & regulator. There are some fairly expensive solutions for this from Atlas, but since the logic and sensors are already present in the PFC, I would like to just use those. This would function almost identically to the way the humidifier works. When CO2 level gets below set level, the spare AC relay will turn on which would open up the regulated gas into the chamber. When the level gets to the set level, the relay would kick off, stopping gas flow.

Here’s the regulator, on/off is controlled by standard 110v ac.

I’m going to attempt to code this myself, feel free to follow along! :slight_smile:


I was just wondering: why not use this one ?
It will cost you less than half that price.
I have very good experience (so far) buying at


I’m not settled on this particular regulator, you’re right there are cheaper alternatives that perform the same function.


You will also need to add an actuator to the arduino module_handler.cpp, add the actuator in the api, and set a controller for it.


@Rckco I’ve got the actuator added in the Arduino and I’m able to control it (AC #3) with AACO 1 1 & AACO 1 0. Could you provide some more detail on what I’m supposed to add/edit for the API within the RPi? Almost there!


Saw this upon running manually.

2016-09-14 15:44:27,799 :: root :: ERROR :: Got AACO 1 0, but can’t find element for it! Ignoring from now on

So I guess it’s receiving the AACO output from the Arduino, just need to poke around some more and find out how to create an “element” for it.

I see all of the actuators within http://(ip)/actuatorType/ but I have no idea how to add to it.


I have not looked at the openag api that much since its not documented well and its complex. So I re-wrote the RESTful server and Python gordaemon and simplified it. Adding a actuator, sensor, and a controller is relatively easy now. I hope to release it very soon after a few test runs.