x50v Race Kart Lap Timer

[SickTripp]

I'm trying to save myself over $400 (commercial racing kart timing system) and find yet another use for my Axim x50v. I will be using it not only to save my GPS track but also to keep track of lap times.

I am creating a system where the Axim will be attached to the steering wheel and show lap times. A simple stopwatch program will do, but I need a way to trigger it automatically. The commercial systems use a magnetic band at the start finish line that can be picked up by a reed switch.

My problem is how to get the signal from the switch into the pocket PC. I have thought of two options:
1. Using the serial interface a piece of software can sense when two pins are shorted out (through the reed switch) using the axim connector modified, or
2. Modify the x50v physically to have direct access to one of the buttons (the home button maybe) and use the reed switch to short it out (this would be the option I would like to avoid, Id rather not have to open my Axim)

I would like to know if anyone's ever tried something like this? I have the pinout for the Axim and looks like I can maybe short out the Tx and Rx pins and be able to detect this with the proper software. Ive never programmed for the pocket PC but I have done some programming in the past. If anyone can point me to a good tutorial for programming the Axim and specifically reading the serial port I would appreciate it.

Any comments, suggestions or past experiences would be helpful.

[Box]

This program lets you set the lap so that it starts and stops automatically for you.
GPS Lap Timing

There are a few of these programs available.
Try a few and see if any work for you.

[SickTripp]

Thats interesting, I hadn't checked them out as I thought that they couldn't be accurate. From the link you provided:

Carried out comparative tests show that in the most situations error margins between 2 and 4 hundreds of second with respect to the lap times obtained from professional timing systems.

Is this true? anyone have experience using GPS to hundredth's of a second? With the position being updated only once a second its hard to believe.

[SickTripp]

Does anyone know of a Pocket PC version of software like this? I found some Palm based programs, but nothing for windows. Anyone actually use it?

the best stopwatch/timing software ive ever used (and i havent used many tbh) is conduits timekeeper

Conduits > Products > Timekeeper: Custom Stopwatch For Your Windows Mobile Pocket PC or Smartphone!

as far as remotely activating and stopping the time, im not that imaginative :1

jd :approve:

[Box]

I did a little googling and Harry's laptimer says it works with ppc wm5 and 6.

Actually I just looked again as I was writing this and it says you can, if you use StyleTap ®. Which is a program to run palm things on PPC.

I've done a bit of reading, and it seems that accurate times are possible, but it relies on a very fast GPS receiver.