Ublox EVK-M8L User manual

EVK-M8L
Evaluation kit
User guide
Abstract
This document describes the structure and use of the EVK-M8L evaluation kit and provides
information for evaluating and testing u-blox M8 ADR positioning technology.
www.u-blox.com
UBX-20028627 - R01
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Document information
Title
EVK-M8L
Subtitle
Evaluation kit
Document type
User guide
Document number
UBX-20028627
Revision and date
R01
6-Aug-2020
Disclosure Restriction
C1-Public
Product status
Corresponding content status
In development /
Prototype
Objective specification
Target values. Revised and supplementary data will be published later.
Engineering sample
Advance information
Data based on early testing. Revised and supplementary data will be published later.
Initial production
Early production information
Data from product verification. Revised and supplementary data may be published later.
Mass production /
End of life
Production information
Document contains the final product specification.
This document applies to the following products:
Product name
Type number
Hardware version
Firmware version
PCN reference
Product status
EVK-M8L
EVK-M8L-0-12
D
Flash FW 3.01
ADR 4.31 M8L
N/A
Production
information
European Union regulatory compliance
EVK-M8L complies with all relevant requirements for RED 2014/53/EU. The EVK-M8L Declaration of Conformity (DoC) is
available at www.u-blox.com under Support --> Product Resources --> Conformity Declaration.
u-blox or third parties may hold intellectual property rights in the products, names, logos and designs included in this
document. Copying, reproduction, modification or disclosure to third parties of this document or any part thereof is only
permitted with the express written permission of u-blox.
The information contained herein is provided “as is” and u-blox assumes no liability for its use. No warranty, either express or
implied, is given, including but not limited to, with respect to the accuracy, correctness, reliability and fitness for a particular
purpose of the information. This document may be revised by u-blox at any time without notice. For the most recent
documents, visit www.u-blox.com.
Copyright © u-blox AG.

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Contents
Document information................................................................................................................................2
Contents ..........................................................................................................................................................3
1Product description ..............................................................................................................................5
1.1 Overview........................................................................................................................................................5
1.2 Kit includes ................................................................................................................................................... 5
1.3 Evaluation software....................................................................................................................................5
1.4 System requirements ................................................................................................................................ 5
2Specifications .........................................................................................................................................6
2.1 Safety precautions ..................................................................................................................................... 6
3Device description.................................................................................................................................7
3.1 Interface connection and measurement................................................................................................7
3.2 Active antenna............................................................................................................................................. 7
3.3 Evaluation unit.............................................................................................................................................7
3.3.1 Antenna connector............................................................................................................................. 7
3.3.2 USB ........................................................................................................................................................8
3.3.3 UART .....................................................................................................................................................8
3.3.4 RST button........................................................................................................................................... 8
3.3.5 Safe boot button................................................................................................................................. 8
3.3.6 Slide switch .......................................................................................................................................... 9
3.3.7 Front connector .................................................................................................................................. 9
3.3.8 LED.......................................................................................................................................................10
3.3.9 Backup battery ..................................................................................................................................10
3.3.10 GNSS configuration .........................................................................................................................11
4Setting up.............................................................................................................................................. 12
4.1 Test vehicle preparation..........................................................................................................................12
4.1.1 Wiring harness of the Head Unit ...................................................................................................12
4.1.2 OBD-II to VSS converter ..................................................................................................................13
4.1.3 Wheel speed sensor .........................................................................................................................13
4.2 EVK-M8L installation ...............................................................................................................................13
4.2.1 Mounting the GNSS antenna .........................................................................................................13
4.2.2 Mounting the EVK-M8L ..................................................................................................................13
4.2.3 Connecting the cables .....................................................................................................................14
4.3 Recommended configuration .................................................................................................................15
4.3.1 Serial port default configuration ...................................................................................................15
4.3.2 ADR configuration ............................................................................................................................15
4.4 Configuration and calibration drive.......................................................................................................18
5Test drives ............................................................................................................................................ 21
6Measuring tracking current ............................................................................................................ 22
7Block diagram ..................................................................................................................................... 23
8Board layout.......................................................................................................................................... 24

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9Schematic ............................................................................................................................................. 27
10 Battery replacement ......................................................................................................................... 28
11 Troubleshooting.................................................................................................................................. 29
12 Common evaluation pitfalls ............................................................................................................ 31
Related documents ................................................................................................................................... 32
Revision history.......................................................................................................................................... 32
Contact.......................................................................................................................................................... 33

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1Product description
1.1 Overview
The EVK-M8L evaluation kit simplifies the evaluation of the high performance u-blox M8 ADR
positioning products. The built-in USB interface provides both power supply and high-speed data
transfer, and eliminates the need for an external power supply. The u-blox evaluation kits are
compact, and their user-friendly interface and power supply make them ideally suited for use in
laboratories, vehicles and outdoor locations. Furthermore, they can be used with a PDA or a notebook
PC, making them the perfect companion through all stages of design-in projects.
Evaluation kit
Description
Suitable for
EVK-M8L
u-blox M8 Evaluation Kit 3D ADR with on-board sensors
NEO-M8L
Table 1: List of products supported by the EVK-M8L evaluation kit
1.2 Kit includes
Evaluation unit
USB cable
Active GPS / Galileo / GLONASS / BeiDou antenna with 3 m cable
Quick Start card
1.3 Evaluation software
The u-center software installation package for the EVK can be downloaded from www.u-
blox.com/en/evaluation-software-and-tools.
Once the .zip file is downloaded, extract the file contents in the Tools folder and double-click the
extracted .exe file. The software components will be installed in your system and placed under the
“u-blox” folder in the “Start > Programs” menu.
The u-center application is an interactive tool for configuration, testing, visualization and data
analysis of GNSS receivers. It provides useful assistance during all phases of a system integration
project. The latest version of the u-center should be used.
1.4 System requirements
PC with USB interface
Operating system: Windows Vista onwards (x86 and x64 versions)
USB drivers are provided in the evaluation kit installation software

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2Specifications
Parameter
Specification
Serial interfaces
1 USB V2.0
1 RS232, max. baud rate 921.6 kBd
DB9 +/- 12 V level
14 pin –3.3 V logic
1 DDC (I2C compatible) max. 400 kHz
1 SPI –clock signal max 5.5 MHz –SPI DATA max. 1 Mbit/s
Speed Pulse interface
Wheel tick: 3.3 V –24 V logic
Forward / Reverse: 3.3 V –24 V logic
Separate isolated vehicle GND connection for wheel tick and Forward/Reverse
signals.
Timing interface
Time-pulse output
Dimensions
105 x 64 x 26 mm
Power supply
5 V via USB or external powered via extra power supply pin 14 (V5_IN) and common
supply/interface ground pin 13 (GND)
Normal Operating temperature
-40 °C to +65 °C
Table 2: EVK-M8L specifications
⚠THE EVK CASE-WORK IS CONNECTED TO THE COMMON SUPPLY/INTERFACE GROUND PIN.
Contact u-blox technical support for assistance if required.
2.1 Safety precautions
EVK-M8L must be supplied by an external limited power source in compliance with clause 2.5 of the
standard IEC 60950-1. In addition to an external limited power source, only separated or Safety
Extra-Low Voltage (SELV) circuits are to be connected to the evaluation kit, including interfaces and
antennas.
☞For more information about SELV circuits see section 2.2 in Safety standard IEC 60950-1 [7].
⚠CAUTION! IN THE UNLIKELY EVENT OF A FAILURE IN THE INTERNAL PROTECTION CIRCUITRY
THERE IS A RISK OF EXPLOSION WHEN CHARGING FULLY OR PARTIALLY DISCHARGED
BATTERIES. REPLACE THE BATTERY IF IT NO LONGER HAS SUFFICIENT CHARGE FOR UNIT
OPERATION. CHECK THE BATTERY BEFORE USING IF THE DEVICE HAS NOT BEEN OPERATED
FOR AN EXTENDED PERIOD OF TIME.

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3Device description
3.1 Interface connection and measurement
To connect the EVK to a PC, use a standard SUBD-9 cable and the included USB cable. The use of
RS232 and external power supply is optional. USB provides both power and a communication
channel.
Connect the wheel tick and forward/reverse signals as well as vehicle ground (GNDA) to the front
connector.
Figure 1: Connecting the unit for power supply and communication
3.2 Active antenna
The EVK-M8L evaluation kit includes a GPS / Galileo / GLONASS / BeiDou antenna with a 3-meter
cable. It is possible to connect various active and passive GNSS antennas with SMA connectors to
the evaluation unit.
The recommended maximum antenna supply current for active antennas is 30 mA.
3.3 Evaluation unit
Figure 2 shows the front and the rear panel of the EVK-M8L evaluation unit.
Front panel
Rear panel
Figure 2: EVK-M8L evaluation unit –front and rear panels
3.3.1 Antenna connector
An SMA female jack is available on the front side (see Figure 2) of the evaluation unit for connecting
an active or passive antenna. The EVK provides a DC supply at the RF input of 3.3 V for active
antennas. The maximum supported antenna current is 30 mA; internal protection limits the
maximum short circuit current to 60 mA.
To avoid the damage of RF input caused by ESD or Electrical Overstress, and to seek maximum
consistency and repeatability of performance independently of the RF component used, the EVK-
M8L has an onboard LNA.

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⚠The connector is only to be used with a GNSS antenna or simulator. Do not connect this
equipment to cable distribution systems.
3.3.2 USB
A USB V2.0 compatible serial port is featured for data communication and power supply.
3.3.3 UART
The evaluation unit includes an RS232 DCE port for serial communication that is compatible with PC
serial ports.
Connect using a straight RS232 serial cable with male and female connectors to the DTE port on
your PC. The maximum cable length is 3.0 meters. To configure the RS232 port, use the UBX-CFG-
PRT command in the u-center application. The maximum operating baud rate is 921.6 kBd.
If you are using a USB to RS232 adaptor cable, you can connect it directly to the evaluation kit RS232
port.
The 9-pin D-SUB female connector is assigned as listed in Table 3:
Pin no.
Assignment
1
not connected
2
TXD, GNSS Transmit Data, serial data to DTE
3
RXD, GNSS Receive Data, serial data from DTE
4
not connected
5
GND
6
not connected
7-9
not connected
Table 3: SUB-D9 connector pin description for EVK-M8L
3.3.4 RST button
The RST button on the front panel resets the unit. To avoid an inadvertent reset, the button is
recessed.
3.3.5 Safe boot button
This is used to set the unit in safe boot mode. In this mode the receiver executes only the minimal
functionality, such as updating new firmware into the SQI flash. In order to set the receiver in
safeboot mode follow these steps.
Press the BOOT button and keep holding it down
Press the RST button
Release the RST button
Release the BOOT button
If the UART interface has to be used, a training sequence has to be sent to the receiver.
The training sequence is a transmission of two bytes 0x55 55 at the baud rate of 9600 Bd. Wait
for at least 100 milliseconds before the interface is ready to accept commands.

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3.3.6 Slide switch
Use the slide switch on the front panel to choose between I2C (and UART) and SPI communication
ports. You must reset the unit by pressing the RST button when the slide switch has been changed.
1. I2C: With this selection, the EVK operates with the UART (RS232 DB9 –rear panel or the 3.3 V
level TXD (MISO), RXD (MOSI) at the front panel). Also the communication via 3.3 V DDC interface
(I2C) is selected.
2. SPI: With this selection, the EVK operates only with the SPI interface. RS232 (DB9) is switched
off.
3.3.7 Front connector
This 14-pin connector provides access to additional functionality to the EVK using various interface
pins. Most importantly, it provides the interface to the vehicle speed pulse (WHEELTICK) input. The
WHEELTICK signal should be adequately de-bounced before application to the EVK input.
The connector also enables measurement of the current used by the EVK. For accurate
measurements, it is recommended to use a cable of at most 1 meter in length.
We recommend using the ACE-AM-0 mating connector or equivalent available from our online shop.
All pins are ESD-protected.

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Pin no.
Pin name
I/O
LEVEL
Description
14
V5_IN
I
4.75 V - 5.25 V
Power input –can be used instead of USB
13
GND
I
-
Common ground pin for case-work, power and serial interface
connections
12
P1A (VCC)
O
3.3 V
Power output –max. current supply 100 mA
1Ω 1% resistor for over-all current measurement to pin 11 (P1B)
NOTE: the current also includes LNA
11
P1B
O
Second connection for overall current measurement
10
P2A
O
3.0 V
Battery output (unloaded)
100 Ω 1% resistor for battery backup current measurement to pin 9
(P2B)
NOTE: There is a current protection to 3 mA. See the circuit in Figure
16 (D2, D4, R29).
9
P2B
O
Second junction for battery backup current measurement
8
TIMEPULSE
O
3.3 V
Time pulse (internally buffered output)
7
WHEELTICK
I
3.3 V - 24 V
Wheel tick input
6
FWD
I
3.3 V - 24 V
Forward/reverse input for speed pulse
5
SDA / CS
I/O
3.3 V
If the slide switch is on I2C, the DDC interface is selected; Function:
data input / output
If the slide switch is on SPI, the SPI interface is selected; chip select
input –LOW ACTIVE
4
SCL / SCK
I/O
3.3 V
Clock input / output
3
TxD / MISO
I/O
3.3 V
If the slide switch is on I2C, the DDC interface is selected / UART TxD
(3.3 V level)
If the slide switch is on SPI, the SPI interface is selected; Master in,
Slave out (MISO)
2
RxD / MOSI
I/O
3.3 V
If the slide switch is on I2C, the DDC interface is selected / UART RxD
(3.3 V level)
If the slide switch is on SPI, the SPI interface is selected; Master out,
Slave in (MOSI)
1
GNDA
I
-
Isolated ground pin to be connected with wheel tick and
Forward/Reverse signals
Table 4: Connector pin descriptions for EVK-M8L (pins numbered from right to left on the front panel)
⚠THE EVK CASE-WORK IS CONNECTED TO THE COMMON SUPPLY/INTERFACE GROUND PIN.
Contact u-blox technical support for assistance if required.
3.3.8 LED
On the front panel of the unit, a single blue LED may be configured to follow the receiver time pulse
signal using the UBX-CFG-TP5 message. The time pulse may be configured so that the LED starts
flashing at one pulse per second during a valid GNSS fix. If there is no GNSS fix, the LED will only light
up, without flashing. The time pulse is enabled by default in the EVK-M8L.
3.3.9 Backup battery
The evaluation unit includes a backup battery. This is necessary to store calibration and navigation
information between operations and to enable immediate startup in DR mode, and fast acquisition
of GNSS signals.