GPS/radio speed pulse signal

[BlackICE]

Most GPS/radio headunit need a speed pulse signal input. Most, if not all of the owners on this forum has used either the Alpina or Pioneer speed pulse generator that reads the rotation of a magnetized tire. Those that tried to use the VSS signal from the transaxle haven't had much luck. The VSS signal is a reluctance sensor that usually generates a sine wave of varying voltage (0-3v) and frequency (proportional to speed). I guess the headunits are expecting a cleaner signal, something like a varying frequency square wave at 0-5v or 0-12v.

My question is does anyone know the electrical specs or the speed input signal. i.e. voltage levels, and frequency range? The reason I am asking is I have a system I am going to install and spec would make it easier to decide if I should buy another "black" box or make one.

It would be relatively simple tap the VSS signal as input into a opt amp comparator to get a square wave and divide it down if the frequency is to great.

 

[Shadowman]

Always tinkering

The Pioneer unit works with many VSS signals however the Clarion single din unit did not as such a pulse generator was required.

I have installed several of the Z1-Z3 units and the only issue that I had on one vehicle was the fact that the pulse rate as created by the gal was to high as such had to be cut in half and then it too worked flawlessly.

Takes care

Shadowman

 

[BlackICE]

Thanks Shadowman. After seeing all of the signals I am going to have to tap into if the VSS didn't work I was considering a using a CAN bus reader to output my required signals. (parking brake, reverse, speed for the GPS) and others signals for a special project.

Definitely more work, but once the investment is made a wealth of information can be had.