Charlie's speaker

A Charlie's Angels speaker, as I call it. A kind of intercom that starts talking on its own.

It has a sensor that detects when I'm near the speaker so it knows when to talk. Based on my class schedule, time of day, etc., he might say one of the following:
- He wishes me good morning in a sweet soft voice when I sleepily crawl behind the PC in the morning.
- What time do I have to leave for work and what time does the train leave
- That I should bring an umbrella because it's going to rain

I made a prototype and built in an intelligent robot that started talking through Google's text-to-speech. But soon I wanted to say something back so I could ask him questions.

Then I designed version 2 of Charlie's speaker. Version 2 consisted of a speaker with Charlie's Angels look and a hand microphone as they used to use with bakkies.

But it turned out to be inconvenient to have to pick up that microphone every time you wanted to ask something.

Version 3
I built version 3 into an old vintage intercom box. This gives you a very ingenious UX: you have to press a switch before he starts listening with his microphone. This is smart of me because pressing a switch when you want to speak is a common interaction with an intercom.

Version 3 is now complete and in use. It contains a lot of electronics: a Raspberry Pi, power amplifier, loudspeaker, microphone, distance sensor VL53L0X and a number of original switches from the intercom itself. I use a MOSFET as a switch to software keep the speaker turned off when Charlie has nothing to say. This is necessary because otherwise you would always hear a slight noise through the speaker. runs a number of web handlers that call the Google APIs, the NS API for the trains and an open data API from the KNMI for the weather.

Openscad files
Microphone holder inside intercom
"Bakkie" microphone
Charlie's Angels intercom


All my gadgets are working installations.

If you want to replicate a gadget and you need help, feel free to contact me.

View 30 gadgets