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VL-MPEu-G3 Reference Manual
Interfaces and Connectors
GPS
The VL-MPEu-G3 incorporates the u-blox NEO-M8T GPS/GNSS receiver using the Mini PCIe
USB 2.0 interface. The NEO- M8T is a low power, high sensitivity receiver suitable for a variety
of embedded applications. See the following u-blox documents at the
for complete information on the NEO-M8T:
It is recommended that you consult the
u-blox NEO-M8T Series product page
updates to these documents.
The latest drivers can be found on the
Antenna Connector (J1)
A single U-FL antenna jack accommodates active antenna types only. Antenna power from the
GPS module is routed through this connector. Output short circuit protection is also provided.
Two antenna models are available from VersaLogic:
•
VL-CBR-ANT02 – GPS antenna with SMA connector (supports GPS signals) or
•
VL-CBR-ANT03 – active antenna with SMA connector (supports GPS and GLONASS
signals)
Battery Back-up
The VL-MPEu-G3 features a soldered-in 3.0V 255 mAh lithium battery. The battery (or an
optional external battery) provides memory retention for the GPS almanac, ephemeris, and last
position.
Note:
VL-MPEu-G3E-Z is shipped without a battery
Warning!
To prevent shorting, premature failure, or damage to the lithium battery, do not
place the board on a conductive surface such as metal, black conductive foam, or
the outside surface of a metalized ESD protective pouch. The lithium battery may
explode if mistreated. Do not recharge, disassemble or dispose of in fire. Dispose
of used batteries promptly.
When using battery power, the time to first-fix in a hot start scenario is reduced to 1-2 seconds
(typical) if the unit has been powered off for less than 2 minutes. Without the battery (or if the
unit has been off for more than 2 minutes), the time to first-fix is approximately 29 seconds
(typical). These first-fix times are based on –130 dBm (approximately 42 db-Hz) or higher
satellite signal levels and will increase as the satellite signal levels drop. In low-signal scenarios,
the first-fix times with a battery can typically range from 2-15 seconds, and without a battery can
typically range from 30-180 seconds.
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