Hall effect with positive output

Other Hardware Sensors
1

Hi, is there a hall effect switch with positive output or do i need to use a transistor?
Need to measure output voltage from several switches.

Trying to do a wind direction sensor like this but with hall switches!
http://maxoberberger.net/projects/arduino-weatherstation/

2

You can read the output of almost any simple Hall effect sensor directly, using the Arduino.