VEMS Community Forum

VEMS => Modifications and Repairs => Topic started by: gunni on October 13, 2009, 09:10:20 PM

Title: Speed signal from GPS instead of a wheel.
Post by: gunni on October 13, 2009, 09:10:20 PM
Now I  have been thinking about this as a feature on PnP solutions and ad on to normal units.

Where can I find a GPS unit that outputs a 0-5v signal as representation of speed . Say 0-250mph or whatever.
I think this could be a great substitution for a Hz signal into the ecu.
And cost wise it shouldn´t be expensive at all.
Title: Re: Speed signal from GPS instead of a wheel.
Post by: [email protected] on October 13, 2009, 09:55:25 PM
Have a read of this: http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=127
Most if not all GPS put out NMEA strings.  This http://www.sparkfun.com/commerce/product_info.php?products_id=8785 would allow a software module to convert your GPS output to the pulses you want.
Title: Re: Speed signal from GPS instead of a wheel.
Post by: gunni on October 13, 2009, 10:37:20 PM
Thanks, I saw all the GPS stuff on the SparkFun site and it seems like adding a GPS module to the ecu that outputs the stream could be the "simplest" way. I.e full GPS logging and viewing in your own standalone ecu is something amazing and can create so many enhanced features. I just don´t know what form of interfacing would be needed .

Unfortunatelly I´m just the last person to be programming things. But maybe I could do it.
Title: Re: Speed signal from GPS instead of a wheel.
Post by: multiplex on October 26, 2009, 08:01:46 PM
only thing i hate about GPS is the time it takes to locate the signal.  I have a racelogic performancebox which is GPS based, but you have to wait a few minutes for it to pick up the signal, etc. Sometimes it drops out.  But besides that, it is great.

Just might want to include some sort of warning light / buzzer if the signal is dropped.

Title: Re: Speed signal from GPS instead of a wheel.
Post by: gunni on October 26, 2009, 11:46:09 PM
That´s only when you don´t have a good signal as you should always use an antenna.

Race Technologies GPS logging picks up a GPS signal within 20seconds from startup .