Making An Old Analogue Intercom Open The Door

We have one of those classic analogue video intercoms next to the front door — a device from a time long before apps.

A door opener I can trigger from my phone or from an automation has been on my list for ages, so I started digging into how this old unit actually works inside.

This clip shows the first results of that analysis: what signals are there, and where a self-built addition could reasonably hook in.