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christopher
09-07-2007, 02:36 AM
I wish to use propeller to display a map with appropriate resolution. Is there an easier way than hand coding the vga display ? The idea is to generate a moving map with gps with a prop replacing a PC.


Thank You

Chris

mcstar
09-07-2007, 02:44 AM
Now that's ambition! I want one of those too! The first question I have, how are you going to store the map information? For a single city you need to store thousands and thousands of line segments and points. I suppose you could use an attached SDcard to store all the data. But, where will you get the data from? Have you decoded Mappoint's or Google Earth's data or something? Of course, you could just store waypoints and tracks (this is what some of the smaller handheld gps units do). Once you have mapping/geocode data that's readable by the prop, it's going to get a lot easier. The TV and VGA drivers available will let you draw lines, text and such.ˇ I've learned loads from LaMothe's literature on how that's done.ˇYou'll then need to virtualize your rendering viewport.ˇ Basically that's where you determine which information is in the current view and what data can be culled. IF you want zooming, that gets a bit complicated, but it's doable.ˇ I built something like this for the desktop PC last year and it worked out fairly well and is currently used in a production environment. (Mappoint and Google earth areˇstill better though).

Post Edited (mcstar) : 9/6/2007 7:49:33 PM GMT

deSilva
09-07-2007, 04:30 AM
I worked in that branch of trade some years ago, when it was still hot http://forums.parallax.com/images/smilies/smile.gif
The processing power of the Prop is absolutely sufficient to do it. A highly optimized net of geo-referenced streets of a major town fits into 1 MB (we used PCMCI cards as memory (now called PC-cards))
Optimal coding and decoding however is tricky....

christopher
09-07-2007, 07:37 AM
Actually, the use is for tracking a passenger ferry at sea as it moves from one point to another destination so land resolution is not critical as I want to convey the vessels general location along the coastline. This will be done by receiving the coords via gps and a gsm modem. I am to generate an outline map of Trinidad and move a pointer (ship) along the coast. I can also label the map. I guess I should search for the Lamothe information as i guess that it is here.

Thanks for the responses

Chris