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

TRMNL X BYOS: Self-Hosting the Server Before the Device Arrives

Correction, October 2026. The display arrived and is running, and parts of this post are wrong or no longer used. Part 2 has what ended up on the screen. I’ve left the original below as a record of what I did before the device arrived, so don’t follow it as written. Wrong: the panel is 10.3 inches at 1872 × 1404 with 16 grays, not 7.5 inches. BYOS doesn’t need the Developer Edition (step 1 under “What’s next”). And the server I run is TRMNL’s own byos_fastapi, not the project linked under “The server”. ...

April 23, 2026 · 4 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

Building Molty: A Telegram Assistant with Memory and Scheduled Checks

ChatGPT worked fine for one-off questions, but it was isolated from the systems I actually use: calendar, email, Strava, GitHub, Obsidian, Spotify, and the half-finished project notes scattered across repos. I wanted a small assistant I could run myself, with persistent memory, scheduled checks, and enough tool access to be useful without turning into a full product. So I built Molty. I didn’t type its code or its instruction files; Molty did, and 81 of the first 83 commits in its workspace repo are under its name. But it wasn’t a one-shot prompt: I was in the details the whole way, directing each change. ...

April 8, 2026 · 7 min · Derek Welty

Building a Concert Discovery Tool with Spotify and Venue Scrapers

I kept missing shows I would have gone to. The data was public, but checking it required a weird amount of manual attention: venue calendars, Spotify history, ticket prices, neighborhoods, and a final “would I actually leave the apartment for this?” filter. So I had Molty, my Telegram assistant, build a weekly concert digest. It wrote all of the code on March 29: the Spotify login, a scraper for each venue, and the scoring. My part was taste: where I go, what I’d pay, how far I’d walk, and telling it when a pick was wrong. Every Monday morning it checks SF venues, matches artists against my Spotify library, and sends a ranked list of shows. ...

March 29, 2026 · 6 min · Derek Welty