How to make VSS Trigger

[Talyn]

You guys really need to check out this site:
http://arduino.cc/

That is what I would do. I used an Arduino to make my multi gauge.

Rear the pulses in, use an if statement to control the door locks using an external relay. Sent a switch in the code so that once it locks the doors once it won't do it again every time you stop and go.

A quick search on pulse counting via a digital input yielded this:
http://arduino.cc/en/Reference/PulseIn
http://www.kishoreinme.in/2010/02/arduino-digital-pulse-counter.html

and: http://gonium.net/md/2006/12/20/handling-external-interrupts-with-arduino/

Another option is to use the data from the OBD II port.
https://code.google.com/p/opengauge/wiki/OBDuino32K

 

[roger55]

In my case, I am wanting to disable my electric radiator cooling fans at over 30 to 40 mph. So, I want the relay to cycle every time the car slows and speeds up again.