Expelliarose

ExpelliaWHAT?

Expelliarose is a game for all those who ever wonder how does it feel to be a wizard. It's kind of a Laser Game in a sorcery world.

Our goal : to create a funny game that can be played anywhere - in your garden, your office or in the corridor of Hogwarts - and with anybody - that means you can play it either with your little sister or with your live-action role-playing team.

The name, ExpelliaRose, is just a mash up between the well known Harry Potter's spell - Expelliarmus -  and our class name - RObotic and Embedeed Systems.

Yeah, but... What's in this game?

To play this game you will need:

• a magic wand (one per player) - the heart of the game. A connected object which can recognize your movement, target your foe, be targeted and with other awesome stuff.
  
• a smartphone (one per player) - connected to the magic wand, an interface between the wand and the server. Moreover, each wizard will have access to different information on his smartphone, like his points (experience and life), the spell he can launch, etc.
  
• a server  - to calculate the result of an attack and synchronize the scores between the player.
  

How does it work?

The Magic Wand:

The Magic Wand includes a lot of functionality:

• Motion recognition: An IMU + a capacitive captor to know when the user is casting a spell + a database of available spell + a smart algorithm of motion recognition, combining rotation of the wand using quaternions plus acceleration matching using DTW. Their are optimized in time and space and stands on a powerful processor (STM32F405) to calculate quickly all this data.
  
• Targeting: 1 IR LED Emitter (to target) and 4 IR receivers (to be targeted). When you cast a spell, the IR Emitter will transmit a specific ID in order your target to recognize you. To avoid problems with artificial lights, the signals is modulated at 38kHz.
  
• LED decoration and other cool stuff: 1 LED strip and 1 powerful RGB LED to make sparkles and lights and decoration when you cast a spell ; 1 vibration motor to feel when you're under attack.
• Sound recognition: A little micro to know if you're saying the right spell (or at least - to know if you're shouting something)
• Communication: a Bluetooth Low Energy module to communicate with your smartphone + USB connector for developing purpose + SW connector for early-developing purpose
• Power: A battery that you can charge via the USB connector

Connection:

The magic wand will be connected wireless to the smartphone through Bluetooth Low Energy.

The smartphone will communicate with the server thanks to WiFi (So, yes. You can't play in the forest, where you don't have your 4G connection...)

PCB and wand design - how does it looks like?

How are we doing?

What are we doing right now?

The final tests !

What is working?

- We have printed our final version of the wand. It is still quite large but that is only for debug purposes.

- Communication scheme is ready : we can talk through IR, the wand is able to be connected to a smartphone, the smartphone's app is available on the Google Play : https://play.google.com/store/apps/details?id=xyz.expelliarose.expelliarose

- Gesture recognition is done using two different algorithms.

- User feedback has been done using funky led strip animation, and vibrating motor.

- A database has created with a plenty of spells and few surprises !