I wanted to make our front door remote-controllable without handing Amazon, Nuki, or any other provider a window into our home. No cloud log tracking exactly when someone comes or goes, no dependency on an app with a paid subscription or one that gets discontinued at some point. So I built my own door opener and hired a butler to operate it.

The name is a nod to my favorite butler, Thomas Barrow, the equally loyal and scheming butler from Downton Abbey. Butler + bot becomes botler, and it opens the door whenever you ask it to.

How it works

Barrow lives as a Telegram bot. When someone in the household messages the bot, the Arduino checks whether that Telegram user ID is on the allowlist, then briefly switches a relay wired directly into the existing intercom system. From the intercom’s perspective, it feels exactly like someone pressing the door release from inside, just triggered remotely via chat.

Only people who are explicitly whitelisted can open the door at all. There’s no permanent logging, no corporation reading along on how often the door opens each day, and no cloud that could someday get hacked, shut down, or sold off.

Technical details

At the heart of it is an Arduino Mega, wired to the internet via an Ethernet shield and polling the Telegram Bot API over that connection. As soon as a message from a known user comes in, the Mega switches a relay wired in parallel to the intercom’s door-release button, triggering it briefly before switching itself back off automatically.