Ublox EVK-M8GZOE User manual

EVK-M8GZOE
Evaluation Kit
User Guide

Abstract
This document describes the structure and use of the EVK-
M8GZOE evaluation kit and provides
information for evaluating and testing the u-blox ZOE-M8G GNSS module. EVK-
M8GZOE is also
suitable to evaluate the GNSS performance of ZOE-M8Q module.
www.u-blox.com
UBX-16030132 - R04

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Document Information
Title EVK-M8GZOE
Subtitle User Guide
Document type User Guide
Document number UBX-16030132
Revision and date R04 10-Jan-2019
Document status Early Production Information
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.
European Union regulatory compliance
EVK-M8GZOE complies with all relevant requirements for RED 2014/53/EU. The EVK-M8GZOE Declaration of Conformity
(DoC) is available at www.u-blox.com within Support --> Product Resources --> Conformity Declaration.
This document applies to the following products:
Product name Type number Hardware version ROM/FLASH version PCN reference
EVK-M8GZOE EVK-M8GZOE-0-00 E ROM SPG 3.01 N/A
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
Evaluation kit versions.......................................................................................................................5
Features................................................................................................................................................5
1.2 Kit includes...................................................................................................................................................5
1.3 Software and documentation...................................................................................................................5
1.4 u-center GNSS evaluation software........................................................................................................6
1.5 System requirements ................................................................................................................................6
2Specifications ......................................................................................................................................... 7
2.1 Safety precautions .....................................................................................................................................7
3Getting Started ...................................................................................................................................... 8
3.1 Software installation..................................................................................................................................8
3.2 Hardware installation.................................................................................................................................8
3.3 Interface default configuration................................................................................................................9
4Device description .............................................................................................................................. 10
4.1 Power supply (ZOE-M8G only)................................................................................................................10
5V main power supply......................................................................................................................10
Backup power supply .......................................................................................................................10
4.2 Interfaces....................................................................................................................................................10
Interface switch ................................................................................................................................11
USB 2.0 micro connector.................................................................................................................11
RS-232 connector.............................................................................................................................11
UART ...................................................................................................................................................12
SPI ........................................................................................................................................................12
DDC (I²C) .............................................................................................................................................12
4.3 GNSS signal inputs...................................................................................................................................12
Active antenna input........................................................................................................................13
1.1.1 Simulator input .................................................................................................................................13
4.4 Digital Connector ......................................................................................................................................14
4.5 LED...............................................................................................................................................................14
4.6 Flash ............................................................................................................................................................14
4.7 RESET_N and SAFEBOOT_N..................................................................................................................15
4.8 EXTINT ........................................................................................................................................................15
5Measuring current consumption (ZOE-M8G only) .................................................................. 16
5.1 Basic measurements with the shunt resistors ..................................................................................16
ZOE-M8G VCC current ....................................................................................................................17
ZOE-M8G V_BCKP current .............................................................................................................18
ZOE-M8G optional Flash and logic current.................................................................................18

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5.2 Measurement with an external current measuring power supply..................................................19
6Testing Power Save Mode ............................................................................................................... 20
7Board assembly ................................................................................................................................... 21
8Schematic ............................................................................................................................................. 24
9Troubleshooting .................................................................................................................................. 26
10 Common evaluation pitfalls ............................................................................................................ 28
Related documents ................................................................................................................................... 29
Revision history .......................................................................................................................................... 29
Contact.......................................................................................................................................................... 30

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1Product description
1.1 Overview
The EVK-M8GZOE evaluation kit simplifies the evaluation of ZOE-M8G and ZOE-M8Q, the u-blox M8
ultra small high performance concurrent GNSS S-LGA modules. 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 or vehicles. 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 versions
Evaluation Kit Description Suitable for
EVK-M8GZOE
(PCB version )
u-blox M8 GNSS evaluation kit with ZOE-M8G ZOE-M8G, ZOE-M8Q
Table 1: List of available evaluation kit
The version identification of the evaluation kit is printed on the PCB board.
Features
•Supports GNSS performance evaluation with simulator and active antenna
o2 SMA connectors; one for simulator use case, one for external active antenna use case
•Populated optional flash
oConfiguration can be saved permanently
oLogging can be done
oAssistNow Offline data can be saved
oOptimal performance of AssistNow Autonomous
oFW can be run from Flash (not by default)
•Current measurement shunt resistors and corresponding measurement pins
o1 Ωshunt resistor makes it easy to convert measured voltage to actual power consumption
oSet of jumpers to bypass these shunt resistors for more advanced power measurements
•RTC crystal and backup supply to evaluate backup, hot start, and warm start functions
o100 Ωshunt resistor to measure backup power consumption
oSuper capacitor of 1F for backup supply
•USB 2.0 connector for both power supply and data transfer
oZOE-M8G module does not support USB connection. For this reason the EVK-M8GZOE board
contains a separate Silicon Labs CP2102 USB to UART Bridge
•RS-232 DB9 connector and digital connector for easy interfacing with UART, SPI and DDC (I²C)
and for evaluating other advanced scenarios
1.2 Kit includes
•Evaluation unit
•Active GNSS antenna with a 3 m cable
•USB cable
☞A plastic cap is attached on the top of the GNSS S-LGA Module in EVK-M8GZOE. The purpose of
the cap is to prevent air flow at ZOE-M8G.
1.3 Software and documentation
The EVK-M8GZOE installation software and documentation can be downloaded from the Web.

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EVK-M8GZOE Quick Start Guide [5] is available from http://start.u-blox.com.
u-center GNSS evaluation software and Windows driver for the evaluation board are available from
web. See section 3.1 for details.
1.4 u-center GNSS evaluation software
The installation software includes u-center, which 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.
1.5 System requirements
•PC with USB or RS-232 interface
•Operating system: Windows 7 onwards (x86 and x64 versions)
•The EVK board includes Silicon Labs CP2102 USB to UART Bridge. Windows drivers for this
interface are available from Microsoft Windows Update service. See section 3.1 for details.

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2Specifications
Parameter Specification
Serial Interfaces 1 USB V2.0
1 RS232, max. baud rate 460.8 kBd
DB9: PC compatible
1 DDC (I2C compatible) max. 400 kHz
1 SPI , max. clock 5.5 MHz, max. data 1Mbit/second
1 UART , max. baud rate 460.8 kBd
Timepulse Timepulse output
Dimensions 83 x 67 x 20 mm
Power Supply 5 V via micro USB connector or external powered via extra power supply pin 2
(V5_IN) and pin 18 (GND) on digital connector
Normal Operating temperature -20°C to +70°C
Table 2: EVK-M8GZOE specification
2.1 Safety precautions
EVK-M8GZOE must be supplied by an external limited power source in compliance with the clause
2.5 of the standard IEC 60950-1. In addition to external limited power source, only Separated or
Safety Extra-Low Voltage (SELV) circuits are to be connected to the evalkit including interfaces and
antennas.
For more information about SELV circuits see section 2.2 in
Safety standard IEC 60950-1 [6]

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3Getting Started
3.1 Software installation
Download and install the u-center GNSS evaluation software from the u-blox website at
https://www.u-blox.com/en/product/u-center-windows.
Once the zip file is downloaded, unzip it and double-click the extracted exe file. The u-center software
will be installed on your system and placed under the “u-blox” folder in the “Start Programs” menu.
Windows drivers for the Silicon Labs CP210x USB to UART Bridge of the EVK are available from
Microsoft Windows Update service. The Windows system driver search mechanism can download
and install the USB drivers automatically from Microsoft Windows Update service. If the automatic
install fails, or if the PC already has an old version of the drivers installed, the correct version of the
driver can be downloaded and installed manually from Silicon Labs at:
http://www.silabs.com/products/mcu/pages/usbtouartbridgevcpdrivers.aspx.
Make sure you select the driver version that does not include “Serial Enumeration” functionality.
3.2 Hardware installation
This section describes the evaluation board connectors and configuration settings that are required
to get started. Figure 1 shows an overview of EVK-M8GZOE board and its connectors.
Figure 1: Getting started overview

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1. Make sure the “Interface Switch” is at RS-232 / USB side (and not SPI side).
2. Connect the jumpers J4, J7 and J6 as above.
3. Connect the evaluation board to a PC by micro USB cable and / or RS-232.
oIf a USB cable is used, then the device is powered by the USB cable.
A USB connection creates a virtual COM port to the PC.
oIf an RS-232 interface is used, the device can be powered by USB cable or by the digital
connector connecting 5 V to pin 2 and GND to pin 18.
oThe green LED (Power LED in Figure 1) is turned on when power supply is connected.
4. Now the blue LED should turn on.
5. Connect the Active Antenna to the “Active” (Active Antenna Input) or the simulator to the
“Passive” input (Simulator Input).
6. Start the u-center GNSS Evaluation Software and select the corresponding COM port and baud
rate, 9600 baud by default (refer to the
u-center User Guide [4] for more information).
7. The blue LED will start blinking once per second during GNSS fixes.
3.3 Interface default configuration
Parameter Description Remark
RS-232, Input UBX and NMEA protocol at 9600 baud
RS-232, Output UBX and NMEA protocol at 9600 baud Only NMEA messages are activated by default
USB, Input UBX and NMEA protocol
USB, Output UBX and NMEA protocol Only NMEA messages are activated by default
Table 3: Default configuration
☞There is also SPI, DDC and UART interface available for debugging and design-in purposes on the
digital connector J1.

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4Device description
4.1 Power supply (ZOE-M8G only)
5V main power supply
The EVK-M8GZOE board must be supplied either by the micro USB connector or by an external 4.5 V
– 5.5 V power supply connected to digital connector pin 2 and GND to pin 18. See Figure 1.
The interface circuitry and other logic on the board relies on the 5 V power supply to always work
properly.
In the default setup, this 5 V main power supply is connected to the low-dropout linear voltage
regulators (LDOs) that provide the 1.8 V VCC voltage of ZOE-M8G.
Power consumption of a ZOE-M8G based design can be easily calculated by measuring the voltage
drop over the VCC current measurement shunt resistor and then multiplying the resulting values by
the 1.8 V power supply voltage. For more information about current measurement of ZOE-M8G, see
section 5.1.
Backup power supply
The backup supply (V_BCKP) of ZOE-M8G is used to supply the ZOE-M8G and the optional RTC
crystal during hardware backup mode (main supply removed). This enables hot start and warm start
capabilities.
The EVK-M8GZOE includes a super capacitor to supply the V_BCKP of ZOE-M8G.
In normal operation, when the main supply of ZOE-M8G (VCC) is present, the backup domain in
ZOE-M8G is supplied by the main supply. V_BCKP supplies the backup domain of ZOE-M8G only
when the main supply VCC is removed.
4.1.2.1 Super capacitor
The capacity of the super capacitor is 1 F and provides backup power over a 100 Ωshunt resistor to
the ZOE-M8G (V_BCKP). When this 1 F capacitor is fully charged to 3.3 V, it can provide backup
power for about 35 hours (t=C*U/I=1*(3.3-1.4)/15uA=126,666 sec. -> ~35 hours).
As soon as the EVK-M8GZOE is supplied, the super capacitor gets charged.
When evaluating very long backup periods, the backup supply can be supplied by the digital
connector J1 pin 1 (2.5 V…3.6 V).
4.2 Interfaces
The EVK-M8GZOE supports all three communication interfaces of ZOE-M8G and ZOE-M8Q: UART,
DDC(I2C) and SPI.
Although the ZOE-M8 modules do not have a USB interface, there is a USB to UART converter on
EVK-M8GZOE that allows communication to ZOE-M8G by USB.
The UART interface of ZOE-M8G is available on USB, RS232 and on digital connector J1. Only use
one of them to communicate.
The SPI and the DDC (I2C) interface are only supported on digital connector J1, see section 4.4.

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Interface switch
The interface switch has to be set according to whether the UART (RS232/USB) and DDC (I²C) or the
SPI interface is to used. See Figure 1 for location of interface switch.
☞Only if the SPI communication interface on the digital connector is used, the interface switch
shall be switched to SPI marking. For all other communication interfaces, it shall be set to the
RS-232 / USB marking.
USB 2.0 micro connector
The USB 2.0 micro B connector can be used for both power supply and communication. On the EVK-
M8GZOE there is a USB to UART converter to the UART interface of ZOE-M8G.
The easiest way to evaluate the EVK-M8GZOE operation is to connect the board to a PC by a micro
USB cable and then to use u-center to configure and monitor the GNSS function.
When the board is connected to the PC, Windows creates a virtual COM port to the PC. This newly
created virtual COM port needs then to be selected on the u-center application.
The UART communication speed is by default set to 9600 baud. Speeds up to 460,800 baud are
supported by ZOE-M8G and ZOE-M8Q.
RS-232 connector
The RS-232 serial port interface can be used to connect the EVK-M8GZOE board to a PC or to other
evaluation host system.
Connect using a straight RS-232 serial cable with male and female connectors. The maximum cable
length is 3 meters. To configure the RS-232 port, use the CFG-PRT command in the u-center
application. The maximum supported operating baud rate is 460,800 baud. 8 data bits, 1 stop bit
and no parity is used. Neither handshaking signals nor hardware flow control signals are available.
The serial port operates in asynchronous mode.
The 9-pin D-SUB female connector is assigned as listed in Table 4.
Pin Nr. Assignment Remarks
1, 6 Timepulse Can be used for aiding purposes
4 Extint0 Can be used for aiding purposes
2 TXD, GNSS Transmit Data, serial data from EVK
3 RXD, GNSS Receive Data, serial data to EVK
5 GND
7, 8, 9 not connected
Table 4: SUB-D9 Connector pin description for EVK-M8GZOE
If the RS-232 interface is used, the device must be powered either by USB cable or by the digital
connector J1 connecting 5V to pin 2 and GND to pin 18.
The UART communication speed is by default set to 9600 baud. Speeds up to 460,800 baud can be
used if the host PC system can reliably support those. Please note that the RS232 of many PCs can
only support up to 115,200 baud.

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UART
The UART RX and TX of ZOE-M8G are available on the digital connector J1 with 1.8 V levels, see
section 4.4 for more information. The UART communication speed is by default set to 9600 baud.
Speeds up to 460,800 baud can are supported by ZOE-M8 modules.
SPI
The SPI interface pins are available on digital connector J1, see section 4.4 for more information.
☞If using SPI interface, the slide switch has to be set accordingly.
DDC (I²C)
The digital connector J1 contains pins for evaluating DDC (I²C) bus communication. For such
evaluation the interface switch must be in correct position: RS-232 / USB.
Additional pull-ups on DDC lines to 1.8 V can be installed on the EVK-M8GZOE if needed, see R4 and
R6 in Figure 10.
4.3 GNSS signal inputs
The EVK-M8GZOE has two RF inputs for GNSS signals. Purpose is to have optimal performance for
“no gain” and for “high gain” use cases. It means basically for passive antenna designs and active
antenna designs.
Figure 2: GNSS signal inputs

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☞Do not use both GNSS inputs at the same time. Either use the passive (simulator) or use the
active antenna input.
Figure 3: EVK-M8GZOE schematic of GNSS inputs
There is a RF switch (U14) which only allows one of the 2 GNSS signal inputs to ZOE-M8G.
Active antenna input
The active antenna input provides 3.3 V supply for active antenna. There is a current limiter circuitry
that limits the maximum current to about 50 mA. Besides the current limiter, there is also a current
detector circuit which has the threshold at 5 mA. That is how the RF switch (U14) is set if the active
antenna Input goes to ZOE-M8G or the Simulator input.
☞Only if current drawn at active antenna input is more than 5 mA, it can be used.
4.3.1.1 Direct ZOE-M8 GNSS performance
There is also an option to have the active antenna input available without connecting an active
antenna. In that case jumper J8 has to be populated, see Figure 2 and Figure 3. Having jumper J8
populated ensures a current draw at active antenna Input and thus the RF switch will still stay at the
active antenna Input.
Thus a passive antenna or simulator can be connected and performance can be verified when have
no external LNA in front of ZOE-M8 modules.
☞There is DC at the active antenna Input, consider to use a DC block.
1.1.1 Simulator input
At simulator input there is an external LNA (U12) used in front of ZOE-M8G to show optimal GNSS
performance. This allows verifying datasheet values of ZOE-M8 modules with a GNSS simulator.
☞Only if NO current is drawn at active antenna Input (< 5 mA), the simulator Input can be used.
Ensure no active antenna is connected to active antenna input and jumper J8 is not populated.

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4.4 Digital Connector
There is a 20-pin connector on EVK-M8GZOE. It provides several PIO’s, interfaces and supply
options. All these pins are ESD protected.
PIN Nr. PIN NAME I/O LEVEL DESCRIPTION
1 V_BCKP I 2.5V…3.6V Backup supply
2 V5_IN I 4.5V…5.5V Main Supply
3 NC
4 GND - GND
5 SAFEBOOT_N I 1.8 V
6 GND - GND
7 SDA / SPI CS_N I/O 1.8V DDC SDA or SPI CS_N, depends on interface switch
8 GND - GND
9 SCL / SPI SCK I/O 1.8V DDC SCL or SPI SCK, depends on interface switch
10 GND - GND
11 TIMEPULSE1 O 1.8V 1PPS
12 GND - GND
13 EXTINT0 I 1.8V
14 GND - GND
15 RESET_N I 1.8V RESET input
16 GND - GND
17 TXD / SPI MISO O 1.8 V UART TX or SPI MISO, depends on interface switch
18 GND - GND
19 RXD / SPI MOSI I 1.8 V UART RX or SPI MOSI, depends on interface switch
20 GND - - GND
Table 5: Connector pin description for EVK-M8GZOE
4.5 LED
On the EVK-M8GZOE, the blue LED shows the time pulse 1 signal. The LED starts flashing with one
pulse per second if doing GNSS fixes. If there is no GNSS fix, the LED will only light, without flashing.
☞With the blue LED, flashing or always on indicate that the EVK-M8GZOE is supplied.
4.6 Flash
There is the optional flash connected to ZOE-M8G on EVK-M8GZOE. By default it can be used for:
•Store the current configuration permanently
•Save data logging results
•Hold AssistNow Offline and AssistNow Autonomous data
The Flash could also be used for running firmware, but by default the firmware runs on the ROM of
ZOE-M8 modules.

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4.7 RESET_N and SAFEBOOT_N
RESET_N and SAFEBOOT_N are available on jumpers (J5 and J10) as well as on digital connector
J1. See section 4.4 for more information.
4.8 EXTINT
On the EVK-M8GZOE, the EXTINT signal of ZOE-M8G is available on digital connector J1 (see
section 4.4), and on RS-232 connector (see section 4.2.3).
☞If EXTINT0 on RS-232 is used, ensure the EXTINT signal available at digital connector J1 is
connected to 1.8 V.

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5Measuring current consumption (ZOE-M8G
only)
5.1 Basic measurements with the shunt resistors
Figure 4: EVK-M8GZOE board measuring the ZOE-M8G VCC current
On the EVK-M8GZOE there is a 1.8 V LDO supplying the ZOE-M8G main supply (VCC). At the input
of that LDO is a 1 Ωcurrent measurement shunt resistor placed in between J7 pin 1 and pin 2, see
Figure 4.
And the V_BCKP for ZOE-M8G is supplied by a super capacitor which gets charged to 3.3 V. In
between the super capacitor and V_BCKP there is a 100 Ωcurrent measurement shunt resistor
placed in between J6 pin 1 and pin 2.

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ZOE-M8G VCC current
To measure the acquisition and tracking power consumption with the EVK-M8GZOE, follow the
below steps, a picture of the setup can be seen at Figure 5:
1. Connect a voltmeter to J7 pin 1 and pin 2 to see the voltage over the 1 Ωcurrent measurement
shunt resistor in the VCC supply.
2. Do a cold reset for the GNSS engine e.g. with u-center software.
3. Read the voltage (and average for a while if necessary) on the voltmeter and convert to current.
1 mV equals 1 mA.
oAverage current consumption from power on to first fix will give you the Acquisition current
consumption as mentioned in ZOE-M8 Data Sheet [1].
oAfter a while when visible SV’s are tracked and all data from the SV’s are downloaded, the
Tracking current as mentioned in
ZOE-M8 Data Sheet [1] can be measured.
Figure 5: Setup to measure the VCC current consumption of ZOE-M8G on EVK-M8GZOE
See Figure 5 as an example where 0.0407V in average are measured by multimeter over 1 ΩVCC
shunt resistor. This corresponds (1 mV equals 1 mA) to 40.7 mA average current.

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ZOE-M8G V_BCKP current
To measure the backup current consumption for V_BCKP of ZOE-M8G follow the below steps, a
picture of the setup can be seen at Figure 6:
1. Connect a voltmeter to J6 pin 1 and pin 2 to see the voltage over the 100 Ωcurrent measurement
shunt resistor in the V_BCKP supply.
2. Disconnect the main supply.
3. Read the voltage on the voltmeter and convert to current. 1 mV equals 10 uA.
Figure 6: Setup to measure the V_BCKP current consumption of ZOE-M8G on EVK-M8GZOE
See Figure 6 for an example where 0.0016V is measured by multimeter over 100 ΩV_BCKP shunt
resistor. This corresponds (1mV equals 10uA) to 16uA backup current.
ZOE-M8G optional Flash and logic current
If the firmware runs on the optional Flash (not the case by default), the current consumption of that
can be measured using J4. See schematic in section 8.

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5.2 Measurement with external current measuring power supply
For customers using their own current measurement setup, the current consumption of VCC and
V_BCKPof ZOE-M8G can also be measured with an external current measuring power supply.
Figure 7: Measuring power consumption with external power supply
In Figure 7, the VCC and V_BCKP power supply circuitry have been disconnected from the main
power supply and Gold Capacitor (J6 and J7 removed). The LDOs are supplied from separate external
power supplies. The jumpers for normal shunt resistor use have been disconnected and the power is
supplied to the LDO connection pins. For the jumpers J12, J13, and J11 the leftmost pin is
connected to the main supply and the rightmost is connected to the corresponding LDO. The J14
GND pins can be used to provide the ground for these external power supplies.
J6 pin 4 (red cable in Figure 7) supplies directly V_BCKP of ZOE-M8G. The voltage level has to be
within 1.4 V to 3.6 V.
The J7 pin 4 (orange cable in Figure 7) supplies the LDO which makes the 1.8 V for VCC of ZOE-M8G.
The voltage level has to be within 2.5 V to 5.5 V.

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6Testing Power Save Mode
When testing Power Save Mode with EVK-M8GZOE, observe the following points:
•A set of predefined power mode setups can be selected using the CFG-PMS message. The
Configuration view or Messages view of the u-center evaluation software can be used to do this.
When enabling the mode using CFG-PMS, always save the configuration by checking the “save
configuration” box in u-center otherwise the configuration will be lost.
•Selecting one of the available setups is the equivalent of using a combination of the configuration
messages with appropriate parameters that impact the power consumption of the receiver.
•u-blox recommends using these predefined settings, except where users have very specific power
saving requirements.
•Note that polling UBX-CFG-PMS will return the setup only if the full configuration is consistent
with one of the predefined Power Mode Setups.
•The evaluation kit can be supplied via the USB connector or at digital connector J1 (pin 2 with 5 V
and pin 18 GND).