Hi, I’m Derek

Electrical engineer building projects at the intersection of hardware and software.

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

A working log of getting Hyperion-NG capture validated on old hardware. Splitter arrives tomorrow, LEDs not yet wired, but the capture pipeline is fully proven end to end. The goal Build a Govee/Philips-Hue-Sync style TV backlight that mirrors on-screen colors to an LED strip behind the TV. Source-agnostic (works with anything plugged into HDMI, not just smart TV apps), running fully local, no cloud, no subscription. The architecture Apple TV (4K) → HDCP-stripping HDMI splitter ─┬→ Samsung TV (4K passthrough) └→ Auvidea B101 (1080p) → Pi 3 (Hyperion-NG) → Ethernet → ESP32 (WLED) → SK6812 LED strip Three things matter about this architecture: ...

May 1, 2026 · 15 min · Derek Welty

IKEA Varmblixt as a Home Assistant Status Light

The IKEA Varmblixt is a $30 RGB+white Zigbee pendant. It pairs directly to ZHA in Home Assistant, has smooth color transitions, and a wide enough color gamut to be useful as a status indicator. I turned it into an ambient display for my apartment — weather during the day, a sunset script at night, a cycling green light at 6:30am, and a solid red door alarm when I forget to close the front door. ...

May 1, 2026 · 6 min · Derek Welty

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

This is a working log. The TRMNL X is ordered but hasn’t arrived yet. The server is running. What is TRMNL X TRMNL makes e-paper displays designed to sit on a desk and cycle through widgets — weather, calendar, news, whatever you build. The X model supports BYOS (Bring Your Own Server), which lets you point the device at your own backend instead of their cloud. That’s the only mode I’m interested in. ...

May 1, 2026 · 4 min · Derek Welty