Missing Protocols - Not many protocols are available.

Pin Collisions - Some boards try to use the same pin.  Not good.
The Double Problem - You cant use the same shield twice.
Arduino IDE/GUI - It can be very hindering

The Solution

Protocol Scarcity and Missing Protocol solution:

XDev was designed with universal function in mind so a unique processor created by XMOS was used. It's different in that it actually can run four concurrent threads at 100MHz each or eight threads at 50MHz. Among other things, these threads allow you to implement protocols in software and run them at the same time like they were hardware based protocols without making a mess of your code or creating timing issues.  Many protocols are already written and unlike other microcontrollers, anything missing can be created.

Pin Collisions and The Double Problem solution:

Each expansion board has an SMD connector on the bottom and one on the top.  The expansion board uses the first pins and then "forwards" the rest to the front so that the next expansion board can use the first pins and not have a pin collision.  It's difficult to explain both clearly and succinctly, so here is an illustration that may help you understand it.

If you were to stack two of these, each board would have it's own two pins, using a total of 4 pins.  This means that even if you are using I2C, you can have multiples of the same expansion board.  Almost all boards listed use three lines, so you can stack five without a problem.

Arduino IDE/GUI:

See the the Software section below.

The Hardware

In addition to the XDev Board, I've also lined up many expansion boards.  Here is a list of what is developed or in progress.

XDev Board features:

• 2 x 2 inches (smaller than Arduino)
• 400MHz XMOS processor with 8 hardware threads
• Loads 64KB programs
• JTAG debug and serial port communication over USB (no drivers required!)
• 1 Megabyte of flash memory storage
• Efficient voltage converters (Arduino and variants are inefficient)
• 15 universal digital I/O pins
• Max I/O speed: 60 MHz
• Common reset pin
• 2 Amps @ 3.3V  to power expansion boards
• Uses the "standard" DC barrel power jack
• Can be powered by USB

IO Breakout expansion features:

• 40 individually programmable lines (GPIO, interrupt or 8-bit bus)
• Prototyping area
• Uses 3 lines

Full Breakout expansion features:

• You get three of these expansion boards when you choose this!
• Breaks out every pin for easy access
• Prototyping area
• Uses all remaining lines! ("topper" board)

Partial Breakout expansion features:

• You get three of these expansion boards when you choose this!
• Breaks out 3 pins (great for [most] SPI or I2C/UART + Interrupt)
• Prototyping area
• Uses 3 lines

SD Card expansion features:

• Supports both SD and SDHC cards (MiniSD and MicroSD using adapter)
• FAT filesystem support is prewritten
• Raw read/write operations supported
• Fancy "push to eject" card slot
• Uses 4 lines

IMU expansion features:

• Awesome deal!
• 9 degrees of freedom
• Three axis magnetometer (compass)
• Three axis accelerometer
• Three axis gyroscope
• Built-in stability filter (MPU-6050)
• Interrupt for event detection (like free falling)
• Uses 3 lines

ZigBee expansion features:

• Wireless communication with other ZigBee devices
• Uses a chip antenna for a minimal footprint
• Uses 3 lines

Audio expansion features:

• A compact SMD speaker for audio output
• A stereo headphone jack
• Great for chiptunes
• Uses 2 lines

Sensor Input expansion features:

• 24 analog sensor inputs
• On-board power booster to give sensors 5V
• 256 programmable interrupts (for things like overheating warnings)
• Uses 3 lines

LiPo/NIHM Battery expansion features:

• Provides an External Power Supply
• Multiple power output terminals
• Uses battery packs 6V or higher
• Current use sensing
• Battery monitor
• Programmable low battery interrupt
• Automatic power off to prevent battery damage
• Uses 3 lines

Dual Motor Driver expansion features:

• Controls two DC motors
• Uses an External Power Supply
• Current use sensing
• Motor stall interrupt
• Uses 3 lines

Dual Stepper Motor Driver expansion features:

• Controls two Stepper motors
• Uses an External Power Supply
• Up to 2 Amps per stepper motor
• 1/16 step microstepping
• Uses 2 lines

Servo Controller expansion features:

• Controls up to 24 servos including digital servos
• Can be used to control hobby RC ESCs
• Uses an External Power Supply
• On-board power converter for up to 10A
• Uses 2 lines

• TFT Screen
• Ethernet
• Bluetooth
• Wifi
• USB Host/Slave interface

Every board comes with standoffs to securely connect each board to ensure they won't break.  Also, external power supplies

In addition to the files for each board, I'll also be uploading Eagle files that you can use as a template for making new boards.  The templates are a pre-routed for the number of pins you want to use.

The Software

Designing hardware is great and all but without the software, it's a paperweight.  Many people including myself are fed up with the subpar Arduino IDE (the GUI for writing code).  To remedy this, XDev provides an easy to use IDE that makes coding a breeze.  You will be able to stack existing boards (prewritten code!) and make custom boards with all the protocols you need in place.  This will generate the code you need to to get developing the rest of your XC/C/C++ code quickly!

Qt Creator is being used as the base of this IDE because it's a mature IDE and is 100% plugin driven.  This makes development time much shorter because one only need to pull out what isnt needed/wanter and make a couple plugins for what is missing without having to muddle in the core of the IDE itself.  Of course the IDE will come bundle with a compiler.

The IDE makes it much easier to manage all your projects.

You can work on both small and large projects with a syntax friendly editor.

Also, interpreting rapidly updating data sent back via printf/println can be confusing so in addition to text output, I'm incorporating data visualizers.  The set of visualizers includes gauges, bars and line graphs and more so that you can easily understand what that sensor is trying to tell you.

I'll be posting code, screenshots and pictures as the project progresses.

Notes:

• You can pick any expansion for every $25 you back the project.
• The date listed is realistic, not just wishful thinking.

Thanks!