UART Bitrate Converter for GPS on Nikon Cameras

Modern Nikon DSLR cameras supports the connection of a GPS on the remote shutter port to include automatic geotagging of the shoots.

The camera uses a small proprietary double-sided connector to receive the position data form a remote GPS unit. The protocol used is the standard NMEA 0183.

Nikon official GPS unit is quite expensive, and I had an old Bluetooth GPS unit which I’m not using anymore but had the NMEA output at the wrong bitrate, as the camera only accept NMEA data at 4800bps, while the GPS works at 38400bps.

This project, made for my good friend and photographer David (checkout his blog!), is a small firmware for an ATMega168 to read the data from an high speed UART port, and reply that on a slower port, using a circular buffer for the data.

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