Exceeding the WORD value on a BS2

Earl Foster

I am using the BS2 in my project and I need to store my altitude which exceeds 65535 feet.· The output format of my GPS using NMEA 0183 is -9999.9 to 99999.9.· I chose·to use the·NMEA format because that is the default on Garmins GPS18 and I only want to use one I/O pin.

I have looked over several codes version from Jon Williams GPS articles but I haven't seen one address altitude and they all seem to use the BS2p.

Hoping someone can help me out!

Jon Williams

Silly question .... Is you project actually going to go above 65535 feet? If not, don't worry about it. If yes, you'll want to check out Tracy Allen's web site (you should anyway, it rocks): www.emesystems.com

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

Earl Foster

Yes my project should go between 80K and 100K feet. It is a high altitude project. I checked out the website you suggested but there is nothing there that I can use for this project. But I did review the NMEA string from the GPS and found that it is in meters, not feet, so it is no longer an issue.

Tracy Allen

I think Jon was probably referring to my double precision math pages at
www.emesystems.com/BS2math6.htm
and not to any stratospheric endevours on my part or on the web pages. I see you have worked it out by dealing in meters instead of feet, and that is a fine way to do it. If by some chance you do want to convert meters to feet and keep to a resolution of 1 foot, there are indeed ways to do it.

Paul Verhage is a Stamper who is involved with high altitude ballooning:
www.parallax.com/html_pages/resources/custapps/app_nearspace.asp

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Tracy Allen
www.emesystems.com