DEJA.JSIOOpen hardware. Open protocols.
Expand your layout with code, not catalogs. Arduinos, Pico Ws, and MQTT — no proprietary modules required.
Your layout, your hardware, your rules
Arduino and Pico W support
Plug-and-play firmware for Arduino Mega and Raspberry Pi Pico W. Drop the sketch on, wire it up, and your devices register themselves with the server on boot.
MQTT native
Every IO device speaks MQTT directly to your server. Subscribe to events, publish commands, compose anything.
Effects, sensors, servos, signals
Wire LED strips, occupancy sensors, servo turnouts, and signals — each one becomes a first-class element in Cloud.
No proprietary modules
Skip expensive proprietary decoders for things a Pico W can do. Open hardware, open firmware, total control.
Open hardware, end to end
Wire it yourself or drop in one of these. Every device speaks MQTT directly to your server.
Raspberry Pi Pico W with DEJA firmware
Arduino Mega wired for effects
Servo-driven turnout mechanism
LED strip lighting a station scene
Occupancy sensor on the mainline
Signal head wired to IO
MQTT to the server. DCC to the track. Nothing proprietary in between.
Every IO device publishes its state and subscribes to commands over MQTT. The server routes messages to the right Cloud element. You never touch a proprietary module or a locked-down protocol.
IO device ──MQTT──▶ server
│
├─WebSocket─▶ throttles
└──Sync─────▶ DEJA CloudLED strips to servo turnouts. No proprietary modules.
If it runs on an Arduino or a Pico W, it can run under DEJA.js. Copy our firmware onto your board, wire it up, and it shows up in Cloud.
- LED scene lighting
- Servo-driven turnouts
- Block occupancy sensors
- Signal heads
- Sound effects
- Anything else you can wire to a GPIO
One account. Every app.
DEJA.js isn't a single tool — it's an open platform for driving, managing, and expanding your layout.
Free to try. No trial timer.
Spin up DEJA.js on your layout today — no credit card, no download for the web apps.
Build the layout you want.
Open firmware, open hardware, open protocols. Start with an Arduino or a Pico W.