Finding a mysterious beep in a box room with Claude Code

The full story

Something in Simon Willison's box room, still full of boxes from a house move, started beeping now and then, too far apart to find by standing and listening. He had Claude Code build Beep Locator, a system that triangulates a sound using several devices placed around the room.

A Python web server shows the main screen, and phones, tablets and laptops join as listeners through a QR code; he used two iPads, a phone, a MacBook Pro and a Surface. The devices play sounds to each other to estimate their positions, though that worked poorly, so a rough mode lets you drag their icons into place. A clapping mode tests it, and once the mystery beep's frequency is confirmed it listens for it, measures the interval and narrows down the most likely spot on a map.

It located the beep to within about 40 cm, and the culprit turned up in that pile of boxes.