VE - Drivers

fastrak

Overview

The fastrak driver supports trackers that use the Polhemus Fastrak protocol for communicating over a serial line. This includes the InterSense IS-900 tracker.

Devices

fastrak

The fastrak device type generates the same standard pos/quat elements as do other head-tracker drivers.

Elements

pos [vector:3]: Describes the position of the tracker in 3-dimensional Cartesian space (x,y,z). This position is relative to the origin of the tracker.
quat [vector:4]: Describes the orientation of the tracker as a quaternion.

Options

line

The name of the serial line device. On Unix systems, this is typically a name beginning with "/dev/tty" (e.g. on Linux, "/dev/ttyS0" is the first serial port). This option must be specified in the device description.

speed

The speed at which the serial line should be run. If not specified, this value defaults to "9600".

flow

The flow control settings that should be used in communication. Possible values are:

xonxoff - use XON/XOFF characters for flow control.
rtscts - use hardware flow control (RTS/CTS lines). This will require an appropriately wired cable between the tracker and the serial port.
none - do not use flow control.

If this value is not specified then the default is "none".

station

The stations to activate. Only those stations mentioned in this option will be enabled and reported.

info

If this option is present and its value is a non-zero integer, then version information about the tracker will be queried and displayed at startup. If not specified (or if specified with the value 0) then no such information is displayed. For debugging/curiosity purposes only.

pos_epsilon

Simple gating value for position information. If specified then changes will only be reported once one of the dimensions of the position has changed by this amount. e.g. if the value of this option is set to '0.01' then a new position read from the tracker will not be passed to the application unless there is a change of at least 0.01 in at least one its dimensions. If not specified the default value is 0.0 (i.e. no gating).

quat_epsilon

Simple gating value for quaternions. If specified then changes will only be reported once one of the dimensions of the quaternion has changed by this amount. e.g. if the value of this option is set to '0.01' then a new quaternion read from the tracker will not be passed to the application unless there is a change of at least 0.01 in at least one its dimensions. If not specified the default value is 0.0 (i.e. no gating).

refang

A set of boresight reference angles in the form:

yaw,pitch,roll

If this is specified then these will be used to boresight the stations. Note currently only one set of reference angles may be specified which will be applied to all stations.

led

Allows the LEDs on an InterSense tracking unit to be turned on ("1") or off ("0") by the driver when it initializes.

Using the Driver

Driver name: fastrakdrv.so

Example:

    driver device fastrak fastrakdrv.so
    device is900 fastrak {
        line /dev/ttyS0
        speed 115200
        flow none
        info 0
        station 1
    }