speed measurement

hello,

i'm new to arduino so i hope some of you would like to help me ? :smiley:

i'm making a speed meter.
i have an arduino uno , the starter kit actually :smiley:

i'll probably need a Hall sensor but that's about all i know.
i'd like it to be accurate to 1km/h if that's possible

does somebody have some schematics ?

thanks,
Fenrir

You want to measure the speed of what? And more importantly, how fast is it expected to be going?
Yes, generally speaking, it is possible to be accurate to 1 km/h. Whether it is possible in your case, we have no idea.
Schematics for what?

Fenrir,
can you tell us more about the project >
What object do you want to measure (car , bicycle, machine, ?)

the speed of a gokart,
i was thinking of maybe using a reed switch ?

range : 0- 15 km/h

thanks :smiley:
Fenrir

more information is needed

you have tires, wheels, shaft, gears, pulleys ?

something that goes round and round onto which you can do something.

a hall effect sensor could measure the passing of a magnet or the teeth of a gear sprocket

a reflective mark on a shaft could trigger a photodiode or some such.

all these would send a pulse, the pulse per revolution could be calibrated to distance traveled. ie: the tire diameter over one revolution of the shaft.
if the shaft is the motor, and that has pulleys or gears, then the rotation of the shaft will not be 1:1 to the tire rotation.