GPS Speedometer

[Don_Kirby]

Here's a small application for reading NMEA GPS data on one com port, and outputting said data on other ports. The hardware used is a ZX24n, a generic NMEA GPS module, and 2 4 digit LED display modules available at SparkFun Electronics. These displays were chosen primarily for their ease of use.

The application is composed of several parts, which I've done my best do document well. Several of the key components, including the sentence parsing routine and the NMEA checksum calculator are written in such a way as to make them easily adaptable to other applications.

As written the displays will show speed (in MPH) and true heading (not magnetic), although with minor modifications, any of the available GPS data could be displayed as well.

If you find any errors or issues with this application, please let me know so that I may update this post.

-Don Kirby