Detect
It watches the PA line and begins recording when the level rises.
A system that catches apartment PA announcements for you, then lets you replay them as sound and text on the web.
In Korea and Japan, wall speakers in apartments carry public-address (PA) broadcasts. Once they finish, you usually cannot hear them again.
PABAL listens continuously, detects the start, records without clipping the beginning, then posts to a web board. The name means Public Address Broadcast Auto Logger.
It covers a handmade Raspberry Pi HAT, an auto-record daemon, and a transcription and publishing web service.
It watches the PA line and begins recording when the level rises.
A pre-roll buffer keeps the opening from being cut off.
Speech becomes text, with personal details masked as needed.
Browse, play, and search past notices on the web.
Hardware
The schematic and system diagram are available as originals. Tap a thumbnail to open them.
From drawing the circuit and mounting it on the wall to the first captured broadcast.