The great thing about the modern world is how connected we are. It’s also the worst thing about the modern world, to be honest. [Allan Binder] wanted to give his toddler the very best of that, and escape the worst, with a specially-designed telephone to call Grandma with– and not get scam calls in turn. We’re not going to say his build guide is so thorough a toddler could follow it, but it’s not too far off.

The device is very simple: a commercial ‘retro-style’ handset pairs with an ESP32-S3 over USB. Said ESP32, aside from acting as a USB host, runs a minimal Session Initiation Protocol (SIP) client, which connects via WiFi to a VoIP account the parent has set up. In this case, [Allan] is using Twilio, but there are other internet telephony providers one could use if a Twilio employee once ran over your dog or something.

There are no inbound calls in this setup, so little Timmy isn’t going  to be bothered needlessly about import fees on nonexistent packages or his car’s extended warranty. Dialing out is toddler-friendly, too– it’s as simple as mashing an arcade button linked to the ESP32’s GPIO. Each designated contact gets a button with its pre-programed contact, like the speed dial of yore. A really nice touch is the use of illuminated buttons tied to the time-zone of the designated contact: kiddo will learn quick that if the button isn’t lit, it’s not time for phone calls. The phone will actually say so, via a text-to-speech that also announces network errors and the like.

While cardboard box housing the prototype seems a bit flimsy to trust with any toddler we’ve met, but the concept here is very sound indeed. We’ve seen such kid-communication devices before, but this implementation, aside from being more current, has a lot to recommend it.

Thanks to [Allan Binder] for the tip!