Re: Nuvi 1450 LMT and OTM2
- Alot of the information you are looking for has been published in the wiki:
The ArgentData products exploit the Garmin proprietary mode and the Fleet Management Interface (FMI) of the Nuvi to display APRS targets and for messaging.
The GTRANS cable does almost the same thing but takes NMEA-0183 from the outside world and maps that to FMI for the Nuvi. The output of the Nuvi is then converted to NMEA-0183 for the outside world.
Note, however, the value of the ID resistor used for the Nuvi 350 is different than that required for the Nuvi 1450. The ID resistor is part of the cable, either molded into the mini-usb connector (Garmin cable) or on the board for the GTRANS cable.