Apple HomeKit-enabled workshop air quality monitor

After I built the cardboard stock sorting shelf, I had about a week of breathing issues as a result of poor ventilation from the sawdust and particulate in the air in my garage. Resolved to avoid another week of feeling crummy, I bought a beefy fan and have eventual plans...

Updated Flipper Zero CO2 Monitor

Well, I finally got around to updating my CO2 Monitor to take advantage of the latest APIs in the Flipper Zero firmware. (It wasn’t quite as bad as I thought it would be 😅) Now it even has its own application icon!

Manually calibrating the Sensiron SCD30 CO2 gas concentration sensor

I picked up an Aranet4 Home CO2 sensor on a Black Friday sale and have finally had the chance to run a commercially-calibrated CO2 sensor against my DIY CO2 monitor on the Flipper Zero and found that my sensor needed some calibration.

Writing software that works with hardware

I’ve been working on a lot of hardware projects lately: making text-to-speech appliances work on transit vehicles, making software for internet-connected signs, prototyping tools to help me make good health decisions, and building out my go-sensors libraries to support physical environment sensors. I’ve spent a lot of my time as...

A story about protocols and documentation

In April 2021, I had a problem at work: I didn’t understand how our on-vehicle application communicated with the text-to-speech appliance to make next stop announcements.

Prototyping a real CO2 monitor on the Flipper Zero

Updated January, 12, 2023

Prototyping a volatile organic compound (VOC) and CO2 monitor on the Flipper Zero

I’ve been playing with environment sensors for a while to help me understand how factors of air quality correlate to my health. In 2019, I had a particularly bad asthma attack that was exacerbated by wildfires in California. Since then, I’ve learned a lot about how 2.5 micron particulate matter...

New housing for RadioShack 22-810 15-Range Digital Multimeter

I was tired of fiddling with the fold-up case that my RadioShack 22-810 multimeter (photo not mine) came in. The probes were a pain to fit into the case properly and I also wanted to have the option to use wires with Dupont connectors to play nicely with my breadboard....

How I turned my Levoit Core 300 air purifier into a fume extractor

For multiple reasons–my asthma, air quality, and COVID-19–I run several air purifiers throughout my home. I run a whole Levoit Core 300 air purifier on top of my desk, which typically is useful for collecting my cat’s dander in addition to putting clean air out close to my face. However,...

I tried to make a watering device for my cat

My cat has an addiction to drinking directly from the tub’s faucet. We’ve tried to get him nice water dishes and electric pump water fountains, but he just craves that good, good tub water. (And is extremely vocal about when he wants to drink.)