>Chris Smolinski wrote:
     >>
     >> If there's anyone who's played with magnetometers and can offer
     >> some advice (or maybe recommend another inexpensive commercial
     >> unit, or a  build-it-yourself option) I'd appreciate it.
     >>
     >
     >Honeywell has a lowcost magnetic field sensor that was used
     >by one of the app's people at Byte Craft when he put
     >together a low cost compass. As I recall it was easy to work with,
     >he had that part of the project running in about a day.
     >
     >Walter Banks
     >http://www.bytecraft.com


     Honeywell makes both a two axis detector ( X-Y ) and a single axis
     detector ( Z ). Using both chips together allows sensing all three
     axes.

     App Notes from Honeywell:

        AN-200 : Smart digital magnetometer in the laboratory
        AN-201 : SET/RESET Pulse circuits for magnetic sensors
        AN-203 : Compass heading using magnetometers
        AN-205 : Magnetic Sensor Cross-Axis Effect

        http://www.ssechoneywell.com



     They are easy to use, the only hitch being the need to supply a 3-4
     amp set/reset pulse to the chip. Their app note AN-201 describes all
     this in great detail.

     Two Axis sensor: HMC-1002, Newark has these on page 1002 @ 30.00 ea
     One Axis sensor: HMC-1001


     They also make a Three-Axis sensor hybrid. Again Newark sells these as
     well. ( Not Cheap @ 250.00 each ).

     Finally, Honeywell makes a complete "Smart Digital Magnetometer" -- It
     uses their sensor hybrid, three CS5509 16 bit A/Ds and a PIC16C73. It
     outputs the X,Y,Z component of the magnetic field at a  rate of 10 to
     154 samples second in ASCII. ( Even more @ 1299.00 )



     Later,

     Tom Hoover
     Software Engineer