QRA JO01OX, WAB TM23, Fists #16909 GQRP #15161 DMR-ID 2342670

NMEA data is basically simple ASCII strings that represent some form of data. They are easily readable and typically look like:


$GPRMC,092750.000,A,5321.6802,N,00630.3372,W,0.02,31.66,280511,,,A*43
$GPGGA,092751.000,5321.6802,N,00630.3371,W,1,8,1.03,61.7,M,55.3,M,,*75

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.

References:

  1. Typical optical isolation circuit.