6 "slots" for replaceable hardware modules
an ~12" 1280x1024 LCD screen in the middle
a "status indicator" slot above the screen - 10 RGB LEDs indicating tasks progress
a drawer with a PIN entry keyboard
(optional, present on one of the sides) extra drawer for final game reward

Main point of this project is to design a framework for these types of entertainment devices, and some reference game task modules.

Hardware

Furniture

80x80x80cm wooden box holding all the modules.

Wiring

All module slots should have CAT5e RJ45-terminated input/output cables available. Whenever a slot does not use a sejfduino module in a specific game - an RJ45 coupler should be used.

"Status indicator" is not generally meant to be replaceable. Some extra hardware features like game finish siren/lamp or extra game finish drawer will be controlled via its sejfduino board.

Certain slots may have extra 12v high power Tamiya connector exposed.

Certain slots may have extra USB female port available for custom functionality (eg. extra audio interface for microphone/speaker)

All wiring runs going to module slots shall have enough slack for simple maintenance (module removal before disconnecting of its cabling)

Main 5v/12v power will be provided by a central ATX power supply.

Raspberry Pi boards should be connected to a 5-port ethernet switch, with static IPv4 networking set up (with "master" board exposing a management/debugging DHCP server)

The only cable coming out of the Furniture shall be a 230v power lead.

Only cabling shared between "sides" shall be ethernet data and 12v power. UBus/RS485 must not be shared between multiple sides - each "side" has its own separate bus managed by its Raspberry Pi board.

sejfduino

A custom Arduino-style board with several special features:

ATMega328PB running at 16MHz - compatiblity with a lot of arduino boards
8P8C/RJ45 input/output connectors for 12v power and RS485 half-duplex communication bus. If a module is removed, it can be easily replaced with a dumb RJ45 coupler, keeping all the wiring inside.
Arduino Pro Mini-style serial programming header
Screw terminals for easy and (fairly) secure connection of extra peripherals

Design files for this board are present in hardware/sejfduino/ directory.

Sejfduino-based modules are running arduino-based code, including an "UBus" library that implements some basic cross-device communication on a half-duplex RS485 bus. See software/arduino/ubus/ and protocol.md for reference on that.

Raspi

Raspberry Pi 3 connected to an LCD screen is present on each of 4 sides of the "Furniture".

Raspberry Pi boards are running Python Kivy based software that takes a role of a ~~master~~ leader on the "UBus" bus.

Game "scenario" is configured there, and sejfduino modules are mostly meant to be a custom human interface devices for specific game tasks.

Code running on the raspberry pi is present in software/raspi/ directory.

raspbian bootstrap (WIP)

apt install -y --no-install-recommends python3-pip python3-virtualenv
apt install -y --no-install-recommends libsdl2-2.0-0 libsdl2-image-2.0-0 libgl1 libmtdev1
python3 -m virtualenv /opt/kivy
/opt/kivy/bin/pip3 install "kivy[base]" kivy_examples

apt-get install --no-install-recommends xserver-xorg-video-all xserver-xorg-input-all xserver-xorg-core xinit x11-xserver-utils unclutter xterm

Sample task modules

16x2 LCD + a potentiometer used as a digit input device - "safebox combination lock dial" entry module
Snake - displayed on screen, with hardware joystick exposed as plain GPIO inputs
NFC card reader - connected over I2C (card found earlier in the game)
"Key" module - plain GPIO input - key found earlier in the game
Barcode scanner - USB port exposed externally, with a separate USB scanner (found earlier in the game)
Electronic drawer with pincode entry