Sidebar – a private ESP32 intercom for five kids, no accounts
Hello all - Inspired by many who build/assemble for their daughters/sons, I took cue and assembled a two-way communication between my son and his friends. Nothing spectacular. Just basic stuff to talk. He is eleven and doesn't have a phone. I wanted him to talk to his friends without an account, a feed, or an algorithm in between, so I built five ESP32-S3 touchscreen units, one per kid. Tap a friend's name, their unit rings. Tap Everyone, they all ring. Each unit dials outbound to a relay I run, so no house opens a port. Audio is uncompressed 16 kHz PCM in 20 ms frames, AES-256-GCM…
In plain words
Sidebar is a private intercom system built on ESP32-S3 touchscreen devices that allows a small group of children to communicate without phones, accounts, or algorithms. Each unit connects through a central relay server, enabling kids to call individual friends or everyone at once by tapping a name. Communication uses encrypted audio over UDP with WebSocket fallback, designed for parents who want their children to experience simple two-way communication similar to ham radios while maintaining privacy and parental control over the contact roster.
written from the facts on this page · September 2026
From the sources
A parent excited by his childhood Hollywood movie portrayal of kids using ham-like radios chatting away to glory wanted to provide that experience to his son and his friends.
In the maker’s words, at launch
Hello all - Inspired by many who build/assemble for their daughters/sons, I took cue and assembled a two-way communication between my son and his friends. Nothing spectacular. Just basic stuff to talk. He is eleven and doesn't have a phone. I wanted him to talk to his friends without an account, a feed, or an algorithm in between, so I built five ESP32-S3 touchscreen units, one per kid. Tap a friend's name, their unit rings. Tap Everyone, they all ring. Each unit dials outbound to a relay I run, so no house opens a port. Audio is uncompressed 16 kHz PCM in 20 ms frames, AES-256-GCM with a fresh key per call, over UDP with an encrypted-WebSocket fallback. To be precise: encrypted to my relay, not end-to-end. No rooms, no recordings, no free-text contacts; the roster lives in a server-side allow-list. I'm a PM, engineer by degree but not by profession - let alone a firmware engineer. I assembled this with Claude as the engineering partner, which is why the write-up includes what went wrong: I shipped an OTA that boot-looped my son's board, and separately "diagnosed" a Cloudflare outage that didn't exist because I tested from the wrong vantage point. Echo is still unsolved. The enclosure was designed in FreeCAD by my son (11); the STLs are in the repo. It was a fun and exhilarating work for me and my son - like most of you would have experienced. Looking forward for your responses/feedback.
Does the same job
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