>Hi all,
>        I am now looking for a new linear position sensor for my robotics
>PIC application.  I decided to leave the infrared LED to sensor link
>alone because of the inherent calibration problems.  It turns out that
>LEDs degrade with time to the point that constant recalibration would be
>required.
>
>        I am now exploring linear encoding for a more digital solution.
>I have come across a type of absolute position linear encoding called
>binary chain code which is a _non-repeating_ pattern of ones and zeros of
>length 2^N.  In an N-bit code _any_ N-bit sequence appears only once in
>the entire 2^N pattern so you always know where your are.
>
>        My sensor is a Texas Instruments TSL213.  It is a 64x1 pixel
>array with a simple 64-bit shift register output.  I can supposedly print my
>pattern on a mylar strip and encode away. I am asking you guys if anyone has
>experience with this type of position encoding especially with a PIC.  Maybe
>one if you has some code written to deal with this.
>
>Thanks,
>
>Martin Kirk
>Arizona State University
>mlk@asu.edu
>(602) 263-9270


HP PhotoOptics has a complete line of positioning sensors and strips for
this purpose.

Doug Sellner
Beach Tech
4131 Vincent Avenue South
Minneapolis MN 55410

Voice (612) 924-9193 x 521
Fax   (612) 926-1145

Internet: dsellner@embay.com