Glowstick

picopi

Simple connected toys built from a single action — turn a knob, press a button, flip a switch.

Each toy is a small wooden box with one big, satisfying control on top. WiFi-enabled ESP32 modules handle the electronics; this repo is the web app and backend that ties them together.

Origin

Picopi started as a sandbox — a place to explore modern Next.js with Server Actions and React Server Components, and to figure out how to self-host the whole stack on a Raspberry Pi.

From there it grew into something much more physical. ESP32 modules, custom PCBs, woodworking, product design — all in service of one goal: building meaningful connected experiences for kids. Not apps on screens, but real objects with weight and texture that do one thing well.

sh0rtwave is the one that struck a chord. A little answering machine for voice messages between kids and the people who love them. Press the button, leave a message. When the light blinks, someone left one for you. The recordings pile up over time into a collection of audio I'll cherish forever.

Toys

Firmware for each device lives under esp32/.

Core technologies

Web app

• Next.js 16 — App Router, React Server Components, and Server Actions
• React 19
• TypeScript
• Tailwind CSS 4
• Motion — UI animations

Backend & data

• PostgreSQL with Drizzle ORM — devices, recordings, users, toggle groups, and more
• Redis — pub/sub for routing real-time commands to connected clients
• Custom Node server (server.ts) — Next.js request handler plus a WebSocket server for live device communication
• Auth.js / NextAuth — Google sign-in and session management
• Zod — runtime validation for API payloads and WebSocket messages
• ffmpeg — audio transcoding and processing (recordings, answering-machine playback)
• Sharp + Tesseract.js — image preprocessing and OCR (e.g. inbound mail parsing) for display on my TRMNL

Hardware

• ESP32 (ESP32-S3) — WiFi, I2S audio, OTA firmware updates
• Arduino / C++ firmware in esp32/shortwave, esp32/toggle, and esp32/knob
• KiCad PCB designs (e.g. esp32/shortwave/sh0rtwave_pcb/)

Infrastructure & hosting

The whole stack runs self-hosted on a Raspberry Pi, deployed and managed through Coolify. The app ships as a Docker image (multi-stage build; production image includes ffmpeg).

Integrations

• Web Push — notifications when new messages arrive
• Gmail API — inbound message processing
• Telegram — device channel integration
• Google OAuth — sign-in and API access

Project structure

app/           Next.js pages, components, server actions, and API routes
db/            Drizzle schema and database client
esp32/         Device firmware and PCB files
lib/           Shared utilities (auth, redis, websocket, push, etc.)
scripts/       CLI helpers (Gmail auth, token generation, DB seeding)
server.ts      Custom HTTP + WebSocket server for production
drizzle/       Database migrations
public/        Static assets and OTA firmware binaries

Getting started

Prerequisites

• Node.js 20+
• PostgreSQL
• Redis

Development

npm install
npm run dev

Open http://localhost:3000.

Production build

In production the app runs on a Raspberry Pi via Coolify, behind a Cloudflare Tunnel, with PostgreSQL and Redis as managed services on the same host.

npm run build          # Next.js build
npm run build:server   # Bundle custom server
npm run build:release  # Build + run with .env.local

Or build the Docker image directly:

docker build -t picopi .
docker run -p 3000:3000 picopi

Environment

Copy and configure environment variables for your local setup (database URL, Redis, auth secrets, API keys). See .env.local and the env.h.example files under esp32/ for device-side credentials.

Database

npx drizzle-kit migrate

License

Private — not open source.