Interfacing a VR (variable reluctance) sensor

Thread Starter


Joined May 25, 2009
Hi all,

I want to interface a VR sensor to an Arduino - this is my first Arduino project.

The VR sensor I have is 380ohm static, and goes momentarily to around 500 or so when a metal object goes in front of it.

Obviously it's probably going to be best to interface it with an IC that converts it to digital?

I have my sights set on a MAX9924 as this seems to do the right job.

I want it to pick up wheel rotations - 4 per revolution - at around 100mph its going to be about 100 pulses per second.

I can take care of the code - using micros() and detecting a change with an "if" statement will probably be enough.

Just wondering if anyone has done this before and can give me some hints. The basic circuit as in the datasheet seems very simple - but not sure about what the Arduino is expecting - I don't want to kill it.