position dispaly on gps screen

[N6ZCT]

I would like to display my position and be able to track others on the display of the gps unit in my car without connecting a laptop....I am using a wysis 7110 and tm261..is this possible..current gps is garmin streetpilot III

[KC0VCU]

Prefice with "I am very likely to be wrong."

If the Streetpilot III GPS receiver will take the raw aprs packets that are coming in, and decode them into a form it can use to dynamically update it's display, (which I happen to think is both a big and unlikely 'if') then feeding the data from the tnc back to the Streetpilot III should suffice. As noted, I don't think it will.

I think you will need some sort of computer to interpret the aprs data received, and either send updated waypoints to the Streetpilot III to display, or use a seprate display from that computer as your method of displaying position and contact information for other aprs users.

Long term, something like that is my intention. I happen to use a gps puck that should work well with a PC to provide my own current location, and either use linux with a soundcard fsk modem, or a seprate tnc to capture other aprs user information, as well as broadcast my own. It should also work well as a digipeater in situations where one would be nice to have.

Part of that long term goal would be to be able to receive the aprs message, determine if the sender is in an otherwise poor transmition area, and only digipeat those messages that need to be repeated. Another part may include keeping track of what aprs ids are in that zone and re-transmitting traffic that is targeted to one of those users as well.

If I am wrong regarding the capabilities of the Streetpilot III, I am sure someone will pipe up.

73
-Rusty - kc0vcu

[K0JEG]

I don't know about the street pilot per say, but both my e-trex vista and my foretrex will display other stations, although they tend to cut off the prefix of the callsign. I just have them set to NMEA. I haven't tried it, but I believe there was a mode on the GPS II+ called NMEA w/waypoint control that would do the same thing.

[KE4NYV]

The Streetpilot III is part of the older generation of Garmin GPS's and just happens to be perfect for what you want!  If you look on the backside, there is a round, four conductor plug that had Ground, Power, TX Data and RX Data.  This port is true RS232 serial data, perfect for APRS.  The SP3 is capable of both NMEA and Garmin Binary data.  

The first most "appliance user" way to do what you want is to buy a Kenwood D700.  This radio is APRS ready and only needs the additon of the GPS.  A simple cable that interfaces the GPS and radio for bi-directional serial comms serves to supply the radio with position data as well as sending $GPWPL strings back to the GPS for mapping.  Basically, when the radio decodes a packet, if the packet has position data, the D700 will take that data and format a $GPWPL waypoint string using the callsign as the waypoint's name.  My company RPC Electronics (www.rpc-electronics.com) manufactures the cable needed to inteface the Garmin to a D700.

You're next option is a soon to be released device from Scott Miller N1VG (www.n1vg.net).  Its the OpenTracker II that is a full TX and RX TNC with waypoint support.  I like this option because you can use the radio you want.  Scott even support native Garmin Binary which will actually use an icon close to the object's instead of a plain old block, like the D700 uses.

Good luck,
Jason KE4NYV
www.ke4nyv.com
RPC Electronics
www.rpc-electronics.com