David VanHorn microbrix.com> writes: > What I'm after, is to plot some points that I'm getting on a serial stream, > onto a map. > Could be a highway map, or anything really. > > The data is in NMEA sentences, and looks like: > $WIMLI,122,132,123.5*50 > > The instrument streams this data at me, 4800 8N1 > This is giving me range and bearing to a lightning strike. > > For the first part, I need to pull up a map centered on where I am, and plot > the strikes on top. > Then I need to "untwist" them based on a compass or GPS heading information, > IOW if I'm headed east, then an apparent 0 degree strike is actually at 90 > degrees on the map, but that's the "bonus points" round. > > Later, I'll want to sort and bin them so that I can separate out storms and > single strikes or "noise" If you have a vector map then you can turn it any way you want using affine transforms. Drawing and clipping a vector map is not very hard, even in VB. I am not sure whether VB is the ideal language for that though. Rotating and clipping an image (bitmap) map can also be done using affine transforms but it will definitely not run in real time if written in VB. Certain scriptable programs (like ImageMagick) can rotate and crop images easily, and even plot text and small images on them (like lightning icons). Just not in VB. Programming this as a server back end and cgi, and rendering in a broswer should be much easier than VB. If you have a laptop running Linux the 'server' can be in your car and a radio link is not needed (but others could surf your 'server' and see where you are in real time, and you could see them). Perl+ImageMagick should be all you need. Also Perl has native interfaces to most SQL databases and you can easily put both the events and your ground track (and other people's ground and not just ground tracks) into a database in real time. Note that writing a VB (or any other) application that manipulates images from scratch would be a major undertaking. Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist