| | | Support for Garmin receivers |
Any Garmin receiver should (theoretically) connect with no problems to
GPSMan. It must be set to use the
Garmin
protocol: in the receiver's
Interface display, under Setup, the Garmin/Garmin
or Garmin option must be selected. Alternatively, for real-time
logging only, it can be set to use the
NMEA 0183 protocol, by
selecting the NMEA option. For the use of this protocol see
above.
When using the Garmin protocol GPSMan may need to convert between bytes and floating point numbers. Tcl/Tk has no machine-independent way to do these conversions and GPSMan only implements them for little- or big-endian architectures that follow the IEEE floating point standard (this will cover most personal computers and workstations). Some Garmin receivers do not use protocols having floating point numbers and are not affected by this. In any case when connecting to the receiver GPSMan tests whether there are problems with the conversions, in which case the user is asked to confirm or cancel the operation.
GPSMan follows closely the "Garmin GPS Interface Specification", December 6 1999, 001-00063-00 Revision 3, available from the Garmin WWW site. This document is known to be already outdated and probably not completely correct, as tests with recent models show.
Some data fields are not directly accessible to the user but are nevertheless kept by GPSMan as hidden information as described above. This is the case with the data on proximity distance, facility name, city, state, country code, and class.
GPSMan identifies the receiver model when it first connects to it. If the receiver implements the Protocol Capabilities protocol the list of protocols it uses is also obtained. This will probably be the case with the more recent models. Otherwise a table for the protocols to use is looked up. At present there are entries in it for the receiver models in the list below.
A problem was detected with a Garmin GPS 12Map that sends some packets twice. This caused havoc in the count of packets and made GPSMan to reset the connection. The solution has been to implement a test for repeated packets that are discarded if a flag is set.
| eMap | eTrex | eTrex Euro | eTrex Legend |
| eTrex Mariner | eTrex Summit | eTrex Venture | eTrex Vista |
| GPSMAP 295 | GPS III Plus | GPS 12Map | |
| GPS 12CX | GPS 12 | GPS 12 (<3.01) | GPS 12 XL |
| GPS 12 XL Chinese | GPS 12 XL Japanese | ||
| GPS 120 | GPS 120 Chinese | GPS 120 XL | GPS 125 Sounder |
| GPS 126 | GPS 128 | GPS 38 | GPS 38 Chinese |
| GPS 38 Japanese | GPS 40 | GPS 40 Chinese | GPS 40 Japanese |
| GPS 45 | GPS 45 Chinese | GPS 45 XL | GPS 48 |
| GPS 55 | GPS 55 AVD | GPS 65 | GPS 75 |
| GPS 89 | GPS 90 | GPS 95 | GPS 95 AVD |
| GPS 95 XL | GPS II | GPS II Plus | GPS III |
| GPS III Pilot | GPSCOM 170 | GPSCOM 190 | GPSMAP 130 |
| GPSMAP 130 Chinese | GPSMAP 135 Sounder | GPSMAP 175 | GPSMAP 180 |
| GPSMAP 195 | GPSMAP 205 | GPSMAP 210 | GPSMAP 220 |
| GPSMAP 230 | GPSMAP 230 Chinese | GPSMAP 235 Sounder |
GPSMan User Manualmig_at_ncc.up.pt, DCC-FC & LIACC,
Universidade do Porto, 2002 | | | Support for Garmin receivers |