View Full Version : Calculating Speed in a car

12-02-2009, 07:17 AM
So my goal here is measure a car's speed. Would I have to use a Vehicle Speed Sense wire or the tachometer wire? Also, I really do not what kind of method either one of those wires use to actually send this particular data to a speedometer. Does it just send pulses or does it send data through CAN BUS? Anyone ever obtain speed data from a car before?

12-02-2009, 08:12 AM
You can read the speed from the OBDII port. Depending on what type of car you have, you can use an ElmXXX chip to ease the burden. (www.elmelectronics.com)

Good luck