> > Is there any way you can think of to shorten the sample period to let's >say 1 second without adding too much expensive hardware (gyroscopes, >accelerometers and such) ? Perhaps some kind of linear regression algorithm >or a PID loop? Magnetic compass. $50 At the GPS read, grab the heading info, and the compass bearing. Now, the compass can read you realtime, your deviation from the GPS heading, until the next sample. -- Where's dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu