PIXEL sensor Serial Readout

Sensors
1

I am excited to integrate my new PIXEL in a new system. I have been poking around the serial output but there are some columns that seem ambiguous to me and I am not having any luck finding documentation about it.

The output looks like:

4574145,13,3.0,nan,100
4575303,13,3.0,nan,100
4576483,13,3.0,nan,100
4577122,10,2.4,nan,100
4578275,10,2.4,nan,100
4579488,10,2.4,3.0,100
4580671,10,2.4,3.0,100
4581310,10,2.4,nan,100
4582503,10,2.4,nan,100
4583688,10,2.4,nan,100
4584327,10,2.4,nan,100
4585485,10,2.4,nan,100
4586650,10,2.4,nan,100
4587284,10,2.4,nan,100
4588517,10,2.4,3.0,100
4589700,10,2.4,3.0,100
4590337,10,2.4,nan,100
4591522,10,2.4,nan,100

And I am assuming the columns are:

timestamp,??,PM2.5 reading,??,??

Any clarification as to what these other columns mean?

Thanks!

2

I don’t have an answer to your query unfortunately, but, Christopher, how were you able to access this information off a pixel?

Did you have to download any drivers in order for it to show up on your computer?

3

Yes, this is the serial output from the PIXEL itself that I am reading from a serial monitor. However, it is output like as I described above, with no reference to what the data in the columns mean. No drivers were necessary for me to access this info.

4

PIXEL serial output breakdown is located here:

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5

Thanks Christopher - I’d missed the serial output part. It’s my first time reading serial output despite lots of using the PurpleAir API.

For the PurpleAir mods, it might be a helpful thing to note in the product page for the Pixel that although you don’t have upload capabilities, you can access the readout through a serial monitor and then recommend say the VSCode Serial Monitor, and when you see the output, the columns are uptime_millis,us_epa_aqi,pm2.5,pm2.5_raw,illuminance_percentage (good find, Doug!).

Then it’s pretty easy to understand why at some point some software update could come through that allows uploading to the map, because all the info you need is already there.

Most of the Reddit complaints about the Pixel that I’ve seen have been that you can only see the LED and not access raw values, and that’s not true with about 2 minutes of tinkering.

6

Oddly enough for an unrelated project I had to install the Silicon Labs CP210x USB to UART Virtual COM Port driver which essentially lets you read serial output as though it’s a regular COM port. I was able to connect via PuTTY and can read values in real-time. Since it’s a terminal the values just scroll so not super useful if trying to save data BUT I’d imagine any utility for reading data via a COM port would work.

That being said, the VSCode Serial Monitor seems promising! I plan to check that out soon.

This is awesome! I didn’t realize I could read values from the device, I just thought it was a light indicator for AQI.

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7

For anyone checking this thread later, PurpleAir has published this article on using the PurpleAir utility to stream data out of the Pixel:

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