How about a 38 khz signal, being sent as 1 ms pulses; a 3 pin IR detector would easily detect the pulses at the distance you want. Keep polling the pulses; if they are interrupted, you increment the counter. This would also work the other way (the vehicle reflects the signal) if you need the trasnmitter and the detector on the same side. In this case, you'll need to shield them from each other to prevent direct crossover, though. Regards, Anand ----- Original Message ----- From: "Richard Prosser" To: "Microcontroller discussion list - Public." Sent: Thursday, October 12, 2006 6:52 AM Subject: Re: [EE] Vehicle detection - magnetic sensors? > Do they need to detect motorbikes / bicycles / golfcarts etc.. > > RP > > On 12/10/06, Debbie wrote: >> --- peter green wrote: >> >> > what are you using theese counts for? >> >> Sounds like they want to check up on ticket sales vs cars in/cars out. >> >> > do in cars and out cars take different routes? >> >> Yep. >> >> > >> > what accuracy do you need (e.g. what proportion of counts can you >> > afford to >> > gain/lose before the data becomes useless to you) >> >> Basically, want to log all cars. The vehicles will be pretty close to the >> sensor and slow moving (<15 k/h) so should give big magnetic sig? Path >> width >> should be, say, <5metres. It's a sports event - as the car park fills up, >> they >> move the poles, path and traffic wardens someplace else. Ditto car >> counter. So >> you probly don't want a gizmo that needs turf dug up or dangles loops or >> is >> fiddly to align. I'm thinking magnetic would be the way to go? Those >> Honeywell >> sensors have analogue o/p but that wouldn't be a big drama. >> Thanks -Debbie >> >> >> >> ____________________________________________________ >> On Yahoo!7 >> Answers: Share what you know and you might make someone's day >> http://www.yahoo7.com.au/answers >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.408 / Virus Database: 268.13.2/472 - Release Date: 11-Oct-06 > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist