LEA-5, NEO-5, TIM-5H - Hardware Integration Manual
GPS.G5-MS5-09027-A2 Released Appendix
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0s Leap second by default
FW 5.00: 14 s Leap second
by default
FW 6.00: 15 s Leap second
by default
Disable SBAS services to achieve 4Hz navigation
With firmware V5.00, no acknowledge (ACK) is returned for the UBX-CFG-
PRT message if the port that is being reconfigured is the same as the port
being communicated over. This is true even in the event of a successful
reception of this message.
Table 15: Main differences between ANTARIS 4 and u-blox 5 software for migration
The default NMEA message set for u-blox 5 is GGA, GLL, GSA, GSV, RMC and VTG. Contrary to ANTARIS 4,
ZDA is disabled by default.
Firmware update is supported by all of these interfaces. The firmware update mechanism of u-blox 5 is more
sophisticated than with ANTARIS 4. It is now based on UBX protocol messages. Customers, who implemented
firmware download in their application processor, will need to replace the software. A template is available from
your u-blox support team.
Please refer to the u-blox 5 Receiver Description including Protocol Specification [4] for more information. This
document is available on the ublox website.
A.3 Hardware Migration
u-blox 5 modules have been designed with backward compatibility in mind but some minor differences were
unavoidable. These minor differences will however not be relevant for the majority of the LEA-4 and TIM-4
designs.
Good performance requires a clean and stable power supply with minimal ripple. Care needs to be exercised in
selecting a strategy to achieve this. Avoid placing any resistance on the Vcc line. For better performance, use an
LDO to provide a clean supply at Vcc and consider the following:
Wide power lines or even power planes are preferred.
Place LDO near the module.
Avoid resistive components in the power line (e.g. narrow power lines, coils, resistors, etc.).
Placing a filter or other source of resistance at Vcc can create significantly longer acquisition
times.
A.4 Migration from LEA-4 to LEA-5
The pin-outs of LEA-4 and LEA-5H/T differ slightly. Table 16 and Table 17 compare the modules and highlight
the differences to be considered.
VDDIO level I/O;
not connected
VDDIO level I/O;
not connected
Can be left open, but connection to VCC is
recommended for compatibility reason (e.g LEA-
5Q). With LEA-5H the I/O voltage is always VCC.