Archive for March 2010

Cut The Cord Already!

March 26, 2010

Disclaimer: Although this blog is used to post information regarding my entry in the Spark 2010 contest – it still is a contest. With that in mind, certain “key differentiators” will not be described in full until after everyone has submitted their projects, and Round 2 is over. Until that point I will post teasers, and some information regarding the Top Secret item.

Q: When is a desktop not portable?   
A: When its tethered to your desk by a power cord.

This year’s Microsoft Spark contest is all about Fun and Games … and there isn’t anything fun about trying to play a “non-computer” game with a 100 foot orange extension cord stretching out behind you. So with that in mind, it’s time to cut the cord and take your desktop out into the world.

(more…)

Detecting Wi-Fi signal strength

March 25, 2010

As I’m sure you will keep finding if you work with WinCE long enough – there are a number of functions, and dlls that exist in standard Windows, that either don’t exist or are almost completely undocumented for Win CE. This can get highly frustrating after a while, but if you keep plugging at it, you can often find a creative solution that meets your needs. Many times, an old thread in a forum that references a snipit of code from PocketPC 2003 is your saving grace. This lack of information extends to the Wireless Zero Configuration (WZC) application programming interface (API) set for CE. WZC is a standardized set of interfaces that Microsoft designed for wireless network cards. If a wireless card’s driver is written to interface with WZC, it can be controlled and queried through this standardized interface, making configuration and status querying code consistent—regardless of the manufacturer of the adapter. While not all wireless cards are WZC–compatible, many are, and the high adoption rate is making it a defacto standard on both Windows-based desktop computers and Windows Mobile operating systems. Unfortunately, the WZC interface in Windows CE is completely undocumented.

Enter the OpenNETCF.Net Smart Device Framework.

(more…)

Real Men Sew

March 19, 2010

As I began to finalize the components of the AAS, I turned my attention to what I was going to use to hold everything together. I knew that I wanted to use some sort of camouflage/military style vest, however the only ones I could find in any stores near me were too pricey, and too bulky. I also knew that whatever I used would need to consist of two layers of fabric, so I can make the vest into a fabric pressure sensor. These requirements led me to create my own vest out of a T-Shirt, and camouflage cloth.

One main benefit of creating the vest myself is that it will allow for me to customize the location of all of the components, embedding them cleanly and transparently into the vest. I am able to minimize the number of wires running throughout the vest by using conductive cloth and conductive thread in the creation. This essentially makes the entire vest a circuit board that I can connect my components to easily, resulting in a significantly more comfortable and lighter weight product.

(more…)

Head Up Display (HUD)

March 18, 2010

Disclaimer: Although this blog is used to post information regarding my entry in the Spark 2010 contest – it still is a contest. With that in mind, certain “key differentiators” will not be described in full until after everyone has submitted their projects, and Round 2 is over. Until that point I will post teasers, and some information regarding the Top Secret item.

What is a Head Up Display? A head-up display (HUD) is any display that presents data without requiring the user to look away from his or her usual viewpoint. The origin of the name stems from the user being able to view information with his or her head “up” and looking forward, instead of angled down looking at lower instruments. The first HUDs were essentially advancements of static gun sight technology for military fighter aircraft. Rudimentary HUDs (more…)

RS232 Interface Circuit

March 15, 2010

For the Advanced Airsoft System, I need to interface a Parallax RFID serial port card reader with the Vortex86DX board. This card reader is a low-cost method for reading passive RFID EM4100 family transponder tags. It has bi-color LED for visual indication of status, and connects via a 2400 baud serial interface. I have used the card reader for one previous project, and fortunately I still had the circuit setup on one of my experimenter boards.

Unfortunately, the random array of wires was in no shape to integrate into the project. Since I need to build this circuit into the clothing that I am creating, having this mess would not do, as something would be bound to come loose.

After validating that the circuit still worked, I decided that it was time to recreate this critical circuit in a less haphazard fashion.

(more…)

People Are Soft!

March 11, 2010

Its true – and while not meant as social commentary, it helps describe my ramblings in this post.

So in doing more testing with the pressure sensor, I realized there was a problem, While the pressure sensor was able to read everything from light touches to hard pressing, and distinguish everything in between, it was not registering the sharp impact from the Airsoft gun. Odd, and VERY frustrating. After rebuilding and retesting the pressure sensor two more times, with the same results, I decided to test another scenario: all-cloth.

Enter the all-cloth pressure sensor…

(more…)

Fabric Pressure Sensor

March 8, 2010

One key component of the Advanced Airsoft System (AAS), is the need to detect when a player has been hit by an airsoft round. Pressure sensors located throughout a body suit and helmet will register the amount of force registered by a shot, providing critical information to the AAS so that it can determine if the player has actually been hit by an airsoft round, if so how much damage is inflicted, and if it equates to the player being “out”.

In determining the best material to use for these pressure switches, I evaluated various load cells, and strain gauges. Unfortunately, after purchasing and testing several of each, I ruled them all out due to either their inflexibility, weight, or cost. This led me to investigate, and ultimately determine that the use of a fabric based pressure sensor would be the best option.

(more…)