Realizing the Data is Garbage

James Proctor

Dec 4, 2025 — 1 min read

It is simply not correct.

Update: It seems like the issue may have been fixed. I'm going to update to the latest and see what I see!

A while back I posted about building an air quality monitor with a Raspberry Pi and an SDS011 sensor. Recently, I realized my Blueair air purifier also has an air quality sensor and a network connection. Could I query that data and incorporate it into my setup?

A screenshot of the Blueair iOS showing it's historical PM2.5 values. — Give me your data.

I found some folks had already created a Home Assistant integration, so I spun up a HA container and got it installed. After setting up an event to write out the sensor values every hour and letting it run for a few days I checked the log file and, unfortunately, the sensor values were all reporting as 0. I initially suspected a precision issue, maybe some kind of rounding error, but tweaking those settings didn't help.

I also considered it could just be a sampling issue. I was only polling once an hour, perhaps those just happened to be the readings at the top of each hour. Eventually a few non-zero values appeared, but they had no apparent relationship to the output shown on the purifier itself, and I validated this by cross-referencing with the Blueair app.

As I investigated, trying to find where things were breaking down, I found an open issue on GitHub. It seems like others have experienced similar challenges with air quality sensor data reporting. I'll keep an eye on the issue and maybe try out this blueair module directly.

Simple 3d render of an alien creature standing amidst a spare landscape.

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Last year I checked out an Intro to 3d Character Design workshop lead by Wyatt Bertz at the Brooklyn Spark makerspace. Over three evenings, we progressed from learning the basics of Blender’s interface and fundamental modeling techniques and used them to build up a scene. We started with simple

Stacked sheets of glass with it's edges cut to specific lengths to represent data values.

Home Depot Culture

I recently came across the proposal I wrote for this project from 2007. In a bit of odd foreshadowing my concept was essentially to do a data visualization, although I don't seem to have known the term. Instead I describe my goal in an incredibly stilted manner. "

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A while back I created this Observable notebook as a reference for rendering particle systems using a few different front-end libraries. You can debate whether 100 particles is 'lots' but this will likely keep your browser happier when all 5 examples are loaded at once. I agree with

An axi-drawn smiley face with some registration problems

Thanks for Visiting

About Me I'm James Proctor, I make art with software tools and work as a developer specializing in data visualization. For a while now I've been focused on the ways the systems we build reflect our values, and using software systems to explore that relationship. I’

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Blending Alien Crabs at Brooklyn Spark

Home Depot Culture

Particles, 5 ways

Thanks for Visiting