Reference ID: GPS
Driver ID: GPS-MX4200
/dev/gpsu; 4800 baud, 8-bits,
This driver supports the Magnavox MX 4200 Navigation Receiver adapted
to precision timing applications. It requires the
line discipline or streams module described in the Line Disciplines and Streams Drivers page. It also
requires a gadget box and 1-PPS level converter, such as described in
the Pulse-per-second (PPS) Signal Interfacing
This driver supports all compatible receivers such as the 6-channel MX 4200, MX 4200D, and the 12-channel MX 9212, MX 9012R, MX 9112.
This driver supports two modes of operation, static and mobile, controlled by clock flag 2.
In static mode (the default) the driver assumes that the GPS antenna is in a fixed location. The receiver is initially placed in a "Static, 3D Nav" mode, where latitude, longitude, elevation and time are calculated for a fixed station. A DOP-weighted running average position is calculated from this data. After 24 hours, the receiver is placed into a "Known Position" mode, initialized with the calculated position, and then solves only for time. The position averaging algorithm does not take into account boundary conditions, so this mode of operation very near the international date line or the poles is not recommended.
In mobile mode, the driver assumes the GPS antenna is mounted on a moving platform such as a car, ship, or aircraft. The receiver is placed in "Dynamic, 3D Nav" mode and solves for position, altitude and time while moving. No position averaging is performed.
The driver writes each timecode as received to the
flag1 0 | 1
flag2 0 | 1
flag3 0 | 1
flag4 0 | 1
Reference Clock Drivers