Magnetic Speed Sensor

Hi,

I am kind of new to Arduino, and I have a magnetic speed sensor similar to this one http://www.fwmurphy.co.uk/images/mp_magnetic_pickups_medres.jpg

Anyone can help and guide me to start from scratch to read the readings from this sensor?

Thank you very much :)

PS

I am using this sensor to read the rpm of a gear.

The website describes them. They have a magnetised core with a winding round it that is held close to the gear wheel - each tooth passing by will cause the magnetic circuit (technically the "reluctance") to to vary and this will induce a voltage on the winding. This is the same basic technology as electric guitar pickups BTW.

The voltage will be greater the greater the speed, and you probably need a voltage-limiting circuit before presenting the output to an ADC. I'd use a 10k + 10k divider between 0V and 5V to give a weak 2.5V supply. Connect this to one end of the winding, and the other end of the winding to an analog pin. Add two diodes from the analog pin to 0V and 5V (so that they won't conduct when the voltage is between 0V and 5V, but will outside this range (protecting the Arduino).

Try looking at the waveform with analogRead() and see what you get for your gearing set up...