NEO-M8P - Hardware Integration Manual
UBX-15028081 - R05
Early Production Information
Hardware description
Page 5 of 27
1
Hardware description
1.1
Overview
The NEO-M8P modules combine the high performance u-blox M8 positioning engine with u-blox’s Real Time
Kinematic (RTK) technology. The NEO-M8P provides cm-level GNSS performance designed to meet the needs of
unmanned vehicles and other machine control applications requiring accurate guidance.
u-blox’s RTK technology introduces the concept of a “rover” (NEO-M8P-0) and a “base” (NEO-M8P-2) on the M8
platform for stunning cm-level accuracy in clear sky environments. The base module sends corrections via the
RTCM protocol to the rover module via a communication link enabling the rover to output its position relative to
the base at cm level accuracies.
Available in industry standard form factors in leadless chip carrier (LCC) packages, the modules are easy to integrate
and combine exceptional positioning performance with highly flexible power, design, and connectivity options.
SMT pads allow fully automated assembly with standard pick & place and reflow-soldering equipment for cost-
efficient, high-volume production enabling short time-to-market.
For all product features, see the
NEO-M8P Data Sheet
1.2
Configuration
The configuration settings can be modified using UBX protocol configuration messages, see the
u-blox 8 / u-blox
M8 Receiver Description including Protocol Specification
[2]. The modified settings remain effective until power-
down or reset. If these settings have been stored in BBR (Battery Backed RAM), then the modified configuration
will be retained, as long as the backup battery supply is not interrupted.
For the NEO-M8P module, the configuration can be saved permanently in SQI flash.
1.3
Connecting power
The NEO-M8P high precision GNSS modules have up to three power supply pins:
VCC
,
V_BCK and VDD_USB
.
1.3.1
VCC: Main supply voltage
The
VCC
pin provides the main supply voltage. During operation, the current drawn by the module can vary by
some orders of magnitude. For this reason, it is important that the supply circuitry be able to support the peak
power for a short time (see the
NEO-M8P Data Sheet
[1] for specification).
When switching from backup mode to normal operation or at start-up, u-blox M8 modules must charge
the internal capacitors in the core domain. In certain situations, this can result in a significant current draw.
For low power applications using Power Save and/or backup modes, it is important that the power supply
or low ESR capacitors at the module input can deliver this current/charge.
Use a proper GND concept. Do not use any resistors or inductors in the power line.
1.3.2
V_BCKP: Backup supply voltage
If the module supply has a power failure, the
V_BCKP
pin supplies the real-time clock (RTC) and battery backed
RAM (BBR). Use of valid time and the GNSS orbit data at start-up will improve the GNSS performance of hot or
warm starts. If no backup battery is connected, the module performs a cold start at power up.
Avoid high resistance on the
V_BCKP
line: During the switch from main supply to backup supply, a short
current adjustment peak can cause high voltage drop on the pin with possible malfunctions.
If no backup supply voltage is available, connect the
V_BCKP
pin to
VCC
.
While power is supplied to the NEO-M8P module through the
VCC
pin, the backup battery is disconnected
from the RTC and the BBR to avoid unnecessary battery drain (see Figure 1). In this case,
VCC
supplies
power to the RTC and BBR.
