BS2, GPS and Compass

NosePicker

Hey I am looking around for the components to complete what "I think" is a fairly simple project and I was wondering based on the project description I will give below if you guys can tell me if I purchase the BS2, gps and compass from this parallax site, would I be able to accomplish a proto type of my project?

Project description:
Step 1. I want to build a device to store the current GPS location in memory of where the device is at, at the time I press a button.
Step 2. When I press a second button I want to be able to read in the saved off locatation and compare it to the current gps location, mixed with input from the compass to determine which direction I need to go to get back to the original gps location. Ultimatly I will have a ring of leds and light the led that is closest to the direction I need to travel.


In short find my way back to where I was originally.
Do I even need the separate compass component or is there some form of direction built-into the GPS component.
I have done a little chip programming and circuit building·but have never worked with a compass or gps before so I know nothing about them.



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Thanks

NosePicker

achilles03

GPS doesn't know what direction you're pointed, but it can calculate which direction you're heading based on the difference between the most recent GPS position and a previous GPS position. You can actually do that without getting the "heading" data from the GPS input. But if you're standing still or not facing the direction you're traveling, then your heading data is useless. In short, unless you plan on constantly walking and holding your device pointed directly in front of you, you'll need a compass.

Yes, you can do it with a BS2, a compass, and a GPS unit, although you might want an eeprom if you plan on storing several GPS locations.

Just as a follow-up, your project will only be accurate to about 25ft or so. So if you're only 50ft away from your target location, your device might not be that accurate. Civilian GPS units aren't super accurate, and can even shift a little from day to day.

Hope that helps,
Dave