What is working:

• A test area is organized.  A local paintball arena and a local Airsoft field are on board for testing the system.
• Impact sensors (two different kinds - piezo and vibe sensor based.) Reliable and working beautifully.
• Spark Cores are programmed and talking to one another and publishing "push" events to the cloud.
• Power source and recharging method decided.
• Low-power mode for recharging, and for auto-off working.
• Laser-cut light diffuser for use in the box tops - frosted Dura-Lar works great.
• Software roadmap and feature list completed as a result.

Here is a Spark Core test setup, making sure all the right things are possible software-wise.

What is next:

• Mechanical design and layout of the Button Boxes and Button Posts. 
• Half the hardware is on hand, the others are being narrowed down from a short-list.
• PCB design once the rest of the electronics are designed and confirmed good.
• Ordering remaining parts for prototypes.