SAM-M10Q - Integration manual
which are functional only with GPS. In addition to the configuration key for each constellation, there
is a configuration key for each signal supported by the firmware. Unsupported combinations will be
rejected with a UBX-ACK-NAK message, and the warning "invalid sig cfg" will be sent via UBX-INF
and NMEA-TXT messages (if enabled).
For example, if CFG-SIGNAL-GPS_ENA is set to zero, all signals from the GPS constellation are
disabled. Alternatively, if CFG-SIGNAL-GPS_L1CA_ENA is set to zero, only the GPS L1 C/A signal is
disabled.
It is recommended to enable QZSS L1C/A when GPS L1C/A is enabled in order to mitigate
possible cross-correlation issues between the signals.
Refer to the interface description [
] for more information on the CFG-SIGNAL-* configuration group.
2.1.1.3 Communication interface configuration
Several configuration groups allow configuring the operation mode of the communication
interfaces. These include parameters for the data framing, transfer rate and enabled input/output
protocols. See
Communication interfaces and PIOs
section for details. The configuration groups
available for each interface are:
Interface
Configuration groups
UART
CFG-UART1-*, CFG-UART1INPROT-*, CFG-UART1OUTPROT-*
I2C
CFG-I2C-*, CFG-I2CINPROT-*, CFG-I2COUTPROT-*, CFG-TXREADY-*
Table 2: Interface configuration
2.1.1.4 Message output configuration
The receiver supports two protocols for output messages: industry-standard NMEA and u-blox UBX.
Any message type can be enabled or disabled individually and the output rate is configurable.
The message output rate is related to the frequency of an event. For example, the output message
UBX-NAV-PVT (position, velocity, and time solution) is related to the navigation event, which
generates a navigation epoch. In this case, the rate for each navigation epoch is defined by the
configuration keys CFG-RATE-MEAS and CFG-RATE-NAV. For example, a value of 1000 ms in CFG-
RATE-MEAS indicates that a measurement is done every second. If CFG-RATE-NAV is set to one (1),
the solution is calculated for every measurement. This means that a navigation epoch is calculated
every 1000 ms. If the rate is set to two (2), only the second measurement is used and the navigation
epoch is calculated every two seconds. The same result is obtained if CFG-RATE-MEAS is set to
2000 ms, and CFG-RATE-NAV is set to one (1). Every 2000 ms a measurement is done, and in
every measurement, a navigation epoch is calculated. However, this second option demands fewer
resources and is the correct procedure when the navigation rate is changed. Setting a navigation
rate value higher than one (1) is only needed when it is required that the raw measurement data is
output at a higher rate than the navigation data.
The output rate for each message is defined in the CFG-MSGOUT-* configuration group. If
the output rate of the message is set to one (1) on the UART interface, CFG-MSGOUT-
UBX_NAV_PVT_UART1 = 1, the message is output for every navigation epoch. If the rate is set
to two (2), the message is output every other navigation epoch. If the rate is zero (0), then the
corresponding message will not be output. As seen in this example, the rates of the output
messages are individually configurable per communication interface.
Some messages, such as UBX-MON-VER, are non-periodic and will only be output as an answer to
a poll request.
UBX-22020019 - R01
2 Receiver functionality
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