is there any way to read the speed you are going from either the computer or some other line? a straight up digital read would be best but i could work with an analog signal and convert it to speed in mph using an A2D converter.

After some research, i found a vehicle speed sensor...does anyone know if it is just a voltage that corresponds to speed? and if it is any idea on how to find the ratio?

 

you want a digital speedometer?

 

ok well the speed sensor runs off of pulses more pulses per second= faster. you could get a sniper special forces tuner that plugs into a laptop and your car it has a full dyno readout of the cars sensors and can record and save the runs plus the ability to really tune the PCM to your likings.

 

no, i want to be able to read the speed my car is going in realtime and have that be an input for some circuits i plan to make. (i want to be able to read the speed of the car when i am actually driving it, not on dyno)

 

Would a portable GPS not work