From: "Richard Sim"
Subject: Re: Detecting moment when a fast moving object passes over a line
X-Newsreader: Microsoft Outlook Express 6.00.2600.0000
Date: Sat, 23 Nov 2002 18:18:42 -0500
NNTP-Posting-Date: Sat, 23 Nov 2002 18:18:38 EST
Organization: Cogeco Cable
"Phil Allison" wrote in message
> ** Such systems as you want are commercially available - as I bet you
> are already aware. I did model electric RC car racing as a hobby for a
> while and the topic of transponders etc was one of considerable interest
> often discussed since a similar system was needed for model boat racing.
Yes, I know there are several commercial systems available; all of which
cost around $3500+, which is far out of the reach of most not-for-profit
> Be assurred that is is NO task for a beginner to tackle.
Ok, perhaps I over-emphasised how much of a beginner I am at electronics. I
have created the complete system already (both the transponder at less than
1.3" sq, consisting of mostly SMT components, and the reciever/decoder), and
it does "work".. just not very reliably (due to the cars powerful motor
magnets, and distance from the start/finish line).
The transponder is controlled by a PIC 12F675, so it may be possible to
differentiate between the magnetic fields with the current circuit and only
code changes on the PIC.. does anyone have any suggestions on how to go
about doing this, and finding correct values/thresholds?