Data Sheet

SAM-M8Q - Data Sheet
UBX-16012619 - R04 Production Information Functional description
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IMES. The receiver also makes available the tracked satellite signal information, i.e. raw code phase and Doppler
measurements in a form aligned to the Radio Resource LCS Protocol (RRLP) [6]. For more details, see the u-blox 8
/ u-blox M8 Receiver Description Including Protocol Specification [2].
1.9 Odometer
The odometer function provides information on travelled ground distance (in meters) based on the position and
Doppler-based velocity output from the navigation solution. For each computed distance since the last odometer
reset, the odometer estimates a 1-sigma accuracy value. The total cumulative ground distance is maintained and
saved in the BBR memory.
The odometer feature is disabled by default. For more details, see the u-blox 8 / u-blox M8 Receiver
Description Including Protocol Specification [2].
1.10 Geofencing
The u-blox SAM-M8Q GNSS patch antenna module supports up to four circular geofencing areas defined on the
Earth’s surface using a 2D model. Geofencing is active when at least one geofence is defined; the current status
can be found by polling the receiver. A GPIO pin can be used to indicate status and, for instance, used to wake
up a host on activation.
1.11 Message Integrity Protection
The SAM-M8Q GNSS patch antenna module provides a function to detect third party interference with the UBX
message steam sent from receiver to host. The security mechanism “signs” nominated messages via a
subsequent UBX message. This message signature is then compared with one generated by the host to
determine if the message data has been altered. The signature algorithm seed can use one fixed secret ID-key set
by eFuse in production and a dynamic ID-key set by the host, enabling users to detect “man-in-the-middle” style
attacks.
1.12 Spoofing Detection
Spoofing is a process whereby a malicious third party tries to control the reported position via a “fake” GNSS
broadcast signal. This may result in the form of reporting incorrect position, velocity or time. To combat this, the
SAM-M8Q GNSS patch antenna module includes spoofing detection measures to alert the host when signals
appear to be suspicious. The receiver combines a number of checks on the received signals to look for
inconsistencies across several parameters.
This feature does not guarantee detection of all spoofing attacks.
1.13 EXTINT: External interrupt
EXTINT is an external interrupt pin with fixed input voltage thresholds with respect to VCC_IO. It can be used
for control of the receiver or for aiding.
For more information about how to implement and configure these features, see the u-blox 8 / u-blox M8
Receiver Description Including Protocol Specification [2] and the SAM-M8Q Hardware Integration Manual [1].
1.13.1 Pin Control
The pin control feature allows overriding the automatic active/inactive cycle of Power Save Mode. The state of
the receiver can be controlled through the EXTINT pin.
The receiver can also be forced OFF using EXTINT when Power Save Mode is not active, see the u-blox 8 / u-blox
M8 Receiver Description Including Protocol Specification [2].
1.13.2 Aiding
The EXTINT pin can be used to supply time or frequency aiding data to the receiver.