Ublox C94-M8P User manual

locate, communicate, accelerate
C94-M8P Application Board
Setup Guide
UBX-16009722 –R02

C94-M8P Board Connections and Interfaces
•J1: RS232 –UART M8P/Radio
•J2: USB –M8P
•J3: External battery / DC
connector
•J6: Debugger interface for radio
module
•J8: UART & GNSS features
•Geofence and RTK status
•Interface to e.g. u-blox C027
•J9: Indicator LEDs
© u-blox AG
Slide 2
J6
J10
J3
J1
J2
J8

Setting up the C94-M8P
Two C94-M8P boards –the “Base” and the “Rover” – need to be set up:
1. Connect the UHF whip antenna to the SMA connector “UHF”
2. Connect the GNSS patch antenna to the SMA connector ”GNSS”
3. Connect the USB port on the board to a PC (for power and configuration)
© u-blox AG
Slide 3

Preparing to Configure the C94-M8P
To configure your C94-M8P kit you need to first:
•Download the latest u-center from
https://www.u-blox.com/en/product/u-center-windows
© u-blox AG
Slide 4

Updating firmware on C94-M8P
•All the changes in configuration are lost when application boards are
updated. The Base and Rover must be re-configured after updating.
•Do not have more than one application board connected to your computer
while updating.
© u-blox AG
Slide 5
Before starting the evaluation, check that the application boards are using the latest
firmware (currently HPG 1.40). Information on the latest firmware is published on the
u-blox web site. To update the firmware, follow the steps described in the u-center
User Guide, chapter 8.1, Firmware update.
See https://www.u-blox.com/en/product/u-center-windows.

Configuring the Base Station
There are three steps to configure the Base Station:
1. Set the position, by having the Base Station do one of the following:
a) survey-in its coordinates
b) be configured with pre-surveyed coordinates
2. Set-up the port for the Radio Link for Port configuration
3. Select RTCM messages for transmission
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Slide 6
The two boards are identical. Select one board to act as a “Base Station”.
The next slides will guide you through the steps needed to configure the Base Station

Step 1 –The Base Station Coordinates
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Slide 7
Use UBX-CFG-TMODE3 to:
•Begin a self survey
•Use, for example, 5 minutes
and 2 meters as targets.
•With a good antenna in a
friendly multipath
environment you can reach
1 meter with a 10-15 min
observation time.
•Or, provide a fixed position
estimate

Step 1 –The Base Station Coordinates
© u-blox AG
Slide 8
•The UBX-NAV-SVIN message allows you
to monitor the survey-in process.
•Self survey finishes when the accuracy
AND time limit are satisfied.
An operating Base
Station indicates its
Fix Mode as “TIME”.
Note that you might
have to disable NMEA
messages to see this
mode correctly.

Step 2 –Base Station Radio Link
© u-blox AG
Slide 9
•Use UBX-CFG-PRT to specify that only RTCM3 data is output on UART1.

Step 3 –Selecting RTCM messages
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Slide 10
For a GPS/BeiDou setup or moving baseline applications, refer to the User Guide (UBX-15031066).
•Use UBX-CFG-MSG to specify that these three RTCM3 messages are
output on UART1.
•1005 (Station coordinates)
•1077 (GPS observations), and
•1087 (GLONASS observations)
•1230 (GLONASS code-phase biases)

Rover Setup Overview
© u-blox AG
Slide 11
•Steps needed to set up the Rover
1. Configure radio link
A Rover that receives RTCM messages will automatically go into RTK operational
mode, and no further configurations are needed.

Step 1 –Rover end Radio Link
© u-blox AG
Slide 12
•Use UBX-CFG-PRT to ensure that UART1 is set up to receive RTCM3
corrections, and that no data is sent out (Protocol out: “none”).

Rover Operation
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Slide 13
•A Rover that receives RTCM corrections will automatically apply these and will:
1. Immediately go into an RTK FLOAT mode
2. Go into RTK FIXED mode once it has resolved the carrier ambiguities
START 1. 2.

Important Note on Antennas
•Rover and Base antennas use ground planes
•The roof of a car can serve as an excellent ground
plane when the patch antenna is placed in the middle
of the roof
•Base antennas are placed in unobstructed
environments
•Also rover antenna placement options should be
carefully examined for each application
•Working in difficult environments and/or without
ground planes will make convergence times long
•See White Paper “Centimeter Navigation with Low
Cost Antennas” (UBX-16010559) published on the
u-blox website for more information
© u-blox AG
Slide 15
•RTK technology depends on continuous carrier phase
tracking, and therefore it is most important that:

Notes on Usage
The C94-M8P kit contains two boards configured to work as a pair
•The default radio configuration supports one Base station transmitting to one
Rover, and no other Base stations must be transmitting in the area. For other
setups, please refer to the User Guide.
© u-blox AG
Slide 16

Notes on the LEDs
© u-blox AG
Slide 17
•Blue LED is blinking when there is
a GNSS position fix (TIMEPULSE)
•If there is no GNSS fix, the
LED will light up without
flashing
•Green LED indicates the RTK
status.
•LED flashes in float mode and
stays on in fix mode.
•The LED is off when there is
no RTK fix.

More Information
•Product website: https://www.u-blox.com/en/product/c94-m8p
•C94-M8P User Guide (UBX-15031066)
•C94-M8P-1-10/11 for China (433 MHz)
•C94-M8P-2-10 /11for USA and Canada (915 MHz)
•C94-M8P-3-10/11 for Europe (433 MHz)
•C94-M8P-4-10/11 for Japan (920 Mhz)
•Note that the connectors differ from the older -00 variants. Please refer to
the last two slides for more connector information.
© u-blox AG
Slide 18

C94-M8P-B Board Connections and Interfaces
•J1: RS232 –UART M8P/Radio
•J2: USB –M8P
•J3: External battery / DC
connector
•J4: UART interface
•J6: Debugger interface for radio
module
•J8:Test & Production interface
•J9: Geofence and RTK status
© u-blox AG
Slide 19
J6 J9 J4
J3 J1 J2 J8

C94-M8P-B Notes on the LEDs
© u-blox AG
Slide 20
•Red LED blinking when the radio
module is transmitting
•Green LED blinking when radio
module ready to receive and on
when link established
•Blue LED blinking when there is a
GNSS position fix (TIMEPULSE)
•Yellow LED indicates RTK status:
•blinking indicates Float
•on indicates Fixed ambiguity
states