Veypor

jcw · Joined: 21 Oct 2006 Posts: 1

On my BMW K1200r there is a wire that sends 12v pulses that are proportional to speed. It is paired in a connector with a switched power and ground. I believe this was used to hook up optional GPS units that also measured speed via the wheel sensor. Can the Veypor use this signal???

Thanks
John

NLEForum · Site Admin Joined: 27 Apr 2004 Posts: 1168

If you have a VR2 unit, then you can use 12V pulsed signals. The Veypor on the other hand can only use 5V pulsed signals for speed detection. The most accurate and best method to detect speed is to use the speed sensor that comes with the Veypor. If you have a shaft drive, you can just put the magnet somewhere on the rotation shaft and mount the sensor on the frame. Then for "circumference" just enter the amount forward the bike moves per rotation of the shaft.

Riccardo · Joined: 18 Nov 2007 Posts: 14 Location: Italy (PG)

Riccardo · Joined: 18 Nov 2007 Posts: 14 Location: Italy (PG)

Riccardo · Joined: 18 Nov 2007 Posts: 14 Location: Italy (PG)

Is there anybody alive out there Question

_________________
Riccardo

Mantignana (PG)
Italy

Riccardo · Joined: 18 Nov 2007 Posts: 14 Location: Italy (PG)

It's unbeliavable!!!! Crying or Very sad

No response in 3 months!!! Crying or Very sad

What's up?
I'm very disappointed! Mad

_________________
Riccardo

Mantignana (PG)
Italy

NLEForum · Site Admin Joined: 27 Apr 2004 Posts: 1168

Hi,

Very sorry for no response - for some reason are notifier for this thread stopped indicating there were new posts.

To answer your question - you can use any pulse from 5V to 12V.

wingerr · Joined: 06 Mar 2010 Posts: 28

The speed sensor signal just needs to be ground switched, so even if the signal is higher than the usual 5V internal pullup, it should work. Should be okay for signals up to 12V.

If for some reason the substitute signal is higher, to prevent any possible problems from the connection of the speed signal to 5V through the VR2's 10k resistor, you could add a diode inline, so that the external signal can only pull current down to ground.

This would protect the transistor from too high a voltage feeding back into the circuit.

NLEForum · Site Admin Joined: 27 Apr 2004 Posts: 1168

Thanks for the clarifications - sounds like you've spent some time working with the speed sensor.

The speed sensor drives a mosfet internally that is protected up to 20V.

wingerr · Joined: 06 Mar 2010 Posts: 28

Yes, I poked around a bit in there when the Q4 PNP transistor became somewhat leaky and had to replace it, which I did successfully-
However, the generic replacement I used didn't have the exact pinout of the original, with the E and C pins swapped. Could I find out what the original part number was?

It works absolutely perfectly as is, but it'd still be nice to put it back to the original clean job as it came from the factory instead of the flywire connection I had to use.
Thanks!

NLEForum · Site Admin Joined: 27 Apr 2004 Posts: 1168

The original part number is:
2N7002 in a SOT-23 package

THe ones used are Fairchild Semi, but any will do.

wingerr · Joined: 06 Mar 2010 Posts: 28

NLEForum · Site Admin Joined: 27 Apr 2004 Posts: 1168

As you guessed, it is really the transitions that matter. The power and current draw of the pullup are negligeable, as is the switching speed (we're talking 100's of Hz, not MHz). It will work in either orientation.

wingerr · Joined: 06 Mar 2010 Posts: 28

Okay, if it doesn't matter whether the processor gets a short positive pulse or a short negative pulse, I'll probably leave it alone for now.
It does appear to work perfectly as I have it set up, so I'll go with that.

I was just wondering if this might have had some bearing on the discontinuity I get on the dyno runs for the speed data collection, where it consistently drops 10 samples near the end of the run. Because it occurs even at low speeds, in low gear runs, it seems to point more toward a software glitch rather than the hardware.