NMEA data is basically simple ASCII strings that represent some form of data. They are easily readable and typically look like:
They are transmitted using the electrical RS-422 standard and this project is designed to convert the data flow from the RS-422 standard to something that can easily be plugged into a USB port on a typical PC. At one end we have an optical isolation circuit and at the other we have an Arduino Pro Micro. When plugged into a PC USB socket the Arduino Pro Mico will appear as a standard COM port.
This can easily be built on Veroboard and the whole device assembled as:
The Arduino is programmed via the USB connection and when connected to a 4800 baud NMEA data feed the data gets sent out of the USB at 9600 baud.
For further information about the software please contact me via the Contact page.