Hall effect switch - help

[Mark Derail]

Visit also http://adafruit.com/, Adafruit has many open source thing-a-ma-bobs and PDF of circuits. "TP" probably stands for Tap Point.
Also a PDF from the manufacturer. http://www.melexis.com/prodfiles/0003715_hallapps.pdf

If you don't have one, get a multimeter! While you're there, get a "breadbox", a small one to get you started. Allows you to wire things up w/o soldiering, perfect for testing. I sometimes use small bb's for completed projects that don't need to be small in size, simple to upgrade things later. A small one can be 5$.

It was a copy / paste image from this site.

http://www.bristolwatch.com/hall_effect/index.htm

Pictured above is a Hall effect switch connected to a light emitting diode. (LED) In the off condition TP2 will be "HIGH" or 5 volts measured relative to ground. The LED will be off. When switched on by a magnet TP2 will measure about .5 volts and the LED will be on.
This can be directly connected to the input port of a micro-controller or other 5-volt digital logic.
The problem with the above circuit is that a Hall sensor is a low power device that can sink about 20 mA. Now we will look at a number of simple circuits to boost the power output of the device.

Basic Transistor Drivers for Micro-Controllers

 

[350xfire]

Damn, too big for your build? Where are you planning on putting it. The Taskled is pretty small... Just wondering.