GTRANS Garmin to NMEA Translator Cable (Kenwood Style)

This cable connects a Garmin nüvi 300 series, StreetPilot c340, StreetPilot 7000 series, StreetPilot 2820 series, StreetPilot 2720 series, or zumo 400 and 500 series navigation receiver to the Kenwood TH-D7A, TM-D700, or TM-D710 radio.

Output is NMEA at 4800 baud with GPRMC, GPGGA, and GPGLL sentences. Waypoint input is accepted in GPWPL or Kenwood proprietary format. Please note that only the nüvi 350 is so far known to display received waypoints properly – other models may display duplicates for moving stations, or no waypoints at all.

Set your radio’s waypoint name length to 9 characters, and set the format to NMEA for the D7 or D700, and Kenwood for the D710. Symbol, altitude, and course/speed information for waypoints is available only from the D710.

You must have the GPS receiver powered through its cradle for the cable to function.

How it Works

Many of Garmin’s current automotive models have a Fleet Management Interface intended to connect to a commercial automatic vehicle location system. Plugging a special cable into the unit causes it to switch from USB mode to a 9600 baud serial mode, where it speaks a proprietary binary protocol.

A 20 MHz microcontroller in the GTRANS cable speaks this protocol on the Garmin side and translate the position, velocity, and time data into NMEA on the fly.