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AirGradient Forum

AirGradient ONE for workshop, want to compare room's air to 3d printer enclosure

#1

Hi, I was wondering if someone could help me as I am sort of a beginner.

I just ordered the AirGradient ONE (AG1) for my workshop main space, and threw in an extra PM, TVOC, and Temp/Hum sensor in my order. I would like to use the extra sensors to do one of two things:

Either:
(1) plug the extra sensors into the AG1 and modify the display code to show both stats, one reading room air and one reading inside 3D printer enclosure; or,
(2) create a whole new and separate (albeit smaller) DIY device that only reads PM, TVOC, Temp/Hum inside the case, with its own screen.

With option (1), I would mount the AG1 on the outside of my enclosure, and wire the extra sensors through the enclosure housing on the inside.

Basically, I want to compare the air quality inside and outside the 3D printer enclosure, and for the inside sensor to tell me when it is safe to access the inside. My enclosure has a fan vent that expels its air outside the window, but I have no way of knowing when the dirty air is down to safe levels.

Does anyone have any pointers? Where to get started? Thanks in advance!

#2

There are only so many ports on the board, so you may have to use a single wire out of the AG ONE and then put the TVOC and Temp chained off each other, which I think would work. But you may have trouble with 2 of the same sensors having the same I2C ID, so I don’t think that would work now that I think of it. Some of the sensors have a resistor you can add or remove to change the ID, but don’t know the specifics.

There aren’t any available hardware UART ports to add another PM sensor, but maybe it would work with a software UART.

With all of it, you would be responsible for coding any required changes since that isn’t a supported config for the base Air Gradient, but that is the beauty of an open hardware solution.

I think it would be easier to get an AirGradient Basic (or a second AG ONE) to put inside of the printer and then have a dashboard in HomeAssistant or something similar to show the values from the two independent AirGradients, rather than try to pull dual duty in a single device

#3

Thanks.

Your post highlighted a lot of limitations to the microcontroller in this regard I was not aware of.

Do you think I could wire the extra sensors to its own microcontroller, a bit-c or pico perhaps, as a separate device? I could write some simple micro-python code to read sensors and output to screen. I want a small form factor inside my enclosure and I’m wondering what the AG1s big PCB offers that I can do without.

What about sensor calibration?

I found a video or two online of people making their own PM sensing device, I’ll try that too, to start.

#4

Have you looked at the AirGradient Basic? Smaller form factor but doesn’t come with the TVOC module but you can add it
DIY Basic Kit (airgradient.com)

It all depends on what you really want to monitor in the printer. CO2 probably doesn’t matter to you and is one of the higher cost items.
If you weren’t afraid of wiring up something without a PCB, you could get a D1 Mini microcontroller, a PMS5003T to do PM2.5 and temp/humidity, and the SGP40 to do TVOC and wire it up yourself for $50-60 or just a bit more for AG Basic and add the TVOC with a small display.

#5

Yes, I agree with @MallocArray the basic kit might be of good use there. I think it will also be easier to keep the two units seperate to avoid I2C address conflicts etc.