Reverse-Engineering the Vornado EOS 9's RF Remote

I bought a Vornado EOS 9 for the bedroom, a Wirecutter pick. It came with a remote, no protocol listed anywhere, no FCC ID that turned up anything useful. Flipper’s frequency analyzer put it near 433 MHz, and Read mode came back with no protocol match, which meant it wasn’t going to be one of the well-known families. (Read mode isn’t broken: pointed at my actual front-door bell, it decodes CAME 12bit at 315 MHz instantly, no histogram needed. The fan’s protocol is just genuinely unlisted.) So it was Read RAW and reverse engineering from scratch, or nothing. ...

August 4, 2026 · 31 min · Derek Welty

Tracking Indoor vs Outdoor Temperature in an SF Apartment

I needed AA and AAA batteries and grabbed an IKEA TIMMERFLOTTE while I was at it. Zigbee temperature and humidity sensor, $8. I put it in my living room: middle of the apartment, between all the windows, so a reasonable representative reading. No real plan. Ten days of data later, I have a clear picture of how this apartment moves heat — and it is not great. Setup The TIMMERFLOTTE logs over Zigbee to Home Assistant. It reports on state change rather than on a fixed interval, so the data is dense: I get a reading whenever temp shifts by about 0.1°F. For outdoor data I’m using Pirate Weather, a privacy-respecting API that pulls from NOAA, exposed as a template sensor in HA: ...

July 29, 2026 · 5 min · Derek Welty

Free OTA TV Anywhere, Using a Box I Already Had

My TV antenna lived behind my TV in the living room. Reception was inconsistent: if someone walked between the antenna and the window, the signal dropped. If I forgot to pull it out and angle it before sitting down, I got nothing. I had an HDHomeRun FLEX DUO from a previous place where I had the antenna setup dialed in. I moved and never got around to setting it up again at the new apartment. The antenna behind the TV was the placeholder that never got fixed. This week I fixed it, and the same day I finished, I used it to watch the FIFA World Cup from an airport lounge and a plane on the way home from a trip, free, with no cable subscription. That felt worth writing up. ...

July 19, 2026 · 7 min · Derek Welty

DIY Ambilight Part 2: Capture Working, LEDs Are Next!

The splitter finally showed up. This session was about seeing if the signal chain actually worked end to end — Apple TV → splitter → TV + B101 — and getting at least one real captured frame out of it. No LEDs wired yet, just proving the capture side works and figuring out the layout. Getting the B101 to see the signal First step after wiring everything up was setting the EDID so the B101 knows what kind of signal to advertise to the Apple TV: ...

May 3, 2026 · 6 min · Derek Welty

Building a DIY Ambilight on a Raspberry Pi 3 with an Auvidea B101

Correction, October 2026: this post and its summary made the project sound further along than it was. HDMI timing detection worked and the capture device showed up, but VIDIOC_STREAMON failed, so no frame was captured here. Part 2 is where a frame finally came out, at 1080p30. The LEDs are not wired yet either. I saw a FancyLEDs sponsorship on YouTube and figured I could build the same thing myself for less, with hardware I already had — including a B101 capture board from a prior project I never finished. Govee makes something similar but it only works with their own app — useless with an Apple TV or anything else plugged into HDMI. I wanted something source-agnostic, fully local, no subscription. This is a working log: capture pipeline is proven, splitter arrives tomorrow, LEDs not yet wired. ...

May 1, 2026 · 16 min · Derek Welty

IKEA Varmblixt as a Home Assistant Status Light

I wanted a passive ambient display that tells me something useful without picking up my phone — weather at a glance during the day, a wind-down mode at night, green at 6:30am if it’s worth cycling to work. The IKEA Varmblixt is $30, Zigbee-native, and pairs directly to ZHA without an IKEA hub. Pairing Not obvious. There’s no reset button. To enter pairing mode, power-cycle the lamp 12 times in rapid succession — plug, unplug, plug, unplug… It flashes white 3–4 times when it’s ready. A smart plug makes this way easier than fumbling with the physical outlet. Source ...

April 13, 2026 · 6 min · Derek Welty