CAM-M8 - Data Sheet

UBX-15031574 - R04

Page 12 of 31

Production Information

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 against this, CAM-M8 series modules include spoofing detection measures to alert

the host when signals appear to be suspicious. The receiver combines a number of checks on the

received signals looking for inconsistencies across several parameters.

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 CAM-M8 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.

1.13.2 Aiding

The

EXTINT pin can be used to supply time or frequency aiding data to the receiver.

For time aiding, hardware time synchronization can be achieved by connecting an accurate time

pulse to the

EXTINT pin.

Frequency aiding can be implemented by connecting a periodic rectangular signal with a frequency

up to 500 kHz and arbitrary duty cycle (low/high phase duration must not be shorter than 50 ns) to

the

EXTINT pin. Provide the applied frequency value to the receiver using UBX messages.

1.14 TIMEPULSE

A configurable time pulse signal is available with CAM-M8 series modules.

The

TIMEPULSE output generates pulse trains synchronized with GPS or UTC time grid with

intervals configurable over a wide frequency range. Thus it may be used as a low frequency time

synchronization pulse or as a high frequency reference signal.

By default the time pulse signal is configured to 1 pulse per second. For more information, see the

u-blox 8 / u-blox M8 Receiver Description Including Protocol Specification [2].