January 7, 2026
On air and under fire
Show HN: I built a "Do not disturb" Device for my home office
Mom-proof meeting sign sparks buy‑vs‑build brawl and family drama
TLDR: A developer built a home office device that shows meeting status by tracking his laptop camera. Commenters split between buying simple busy lights or hacking cheap bulbs, while one scathing reply said, “talk to your mom”—underscoring that work‑from‑home boundaries and low‑cost fixes often beat complex hardware.
Hacker News lit up over a home‑office “do not disturb” gadget a dev built to keep parents from barging in. He rigged a tiny board to show when his laptop camera is on, hacked Apple’s logs to detect it, and even dreamed up a one‑person protocol. But the comments turned it into family therapy meets maker showdown.
Practical folks swore by off‑the‑shelf busy lights—Kuando and neon “ON AIR” signs—while one buyer threw shade at OnAirWarning: “It completely sucks.” The lazy‑genius crowd bragged about $7 color bulbs set to red, and someone wanted to repurpose an old crosswalk sign with a countdown.
The spiciest take accused the builder of dodging a real conversation with his mom, igniting a debate over gadgets vs boundaries. Others chuckled at the relatable detail of phones buried under pillows and surprise Slack huddles that become 45‑minute epics. A few nerds cheered the log‑hacking trick, side‑eyeing Apple’s locked‑down camera status, while noting the assist from AI. The vibe: half the room says “just buy a sign,” the other half says “this is art,” and one corner is yelling “talk it out.” Meanwhile, the internet keeps arguing about how to keep the peace at home—without muting real life.
Key Points
- •A custom Do Not Disturb device was built with an ESP32 to display meeting status based on MacBook camera activity.
- •Calendar sharing was insufficient due to missed phone alerts, unplanned meetings, and the need to show nuanced states like “camera off but present.”
- •Apple provides no public API for camera status, so the author monitored macOS logs for AVCaptureSession start/stop notifications.
- •A Bun-based process streams and filters log output (including com.apple.cameracapture) and serves status to the ESP32 over Wi‑Fi.
- •The project includes a bespoke single-user binary protocol and was developed in early 2025, with Claude assisting the log-monitoring approach.