Hardware Overview

Important: Read Before Use!

ESD Sensitivity

The mosaic-X5 module is sensitive to ESD. Use a proper grounding system to make sure that the working surface and the components are at the same electric potential.

ESD Precaution

As recommended by the manufacturer, we highly recommend that users take the necessary precautions to avoid damaging their module.

The Tri-band GNSS RTK breakout board features ESD protection on the USB-C connector and breakout's I/O:
- USB data lines
- I/O PTH pads
- JST connector's pins
The mosaic-X5 module features internal ESD protection to the ANT_1 antenna input.

iFixit Anti-Static Wrist Strap
TOL-25572

Active Antenna

Never inject an external DC voltage into the SMA connector for the GPS antenna, as it may damage the mosaic-X5 module. For instance, when using a splitter to distribute the antenna signal to several GNSS receivers, make sure that no more than one output of the splitter passes DC. Use DC-blocks otherwise.

Info

A 3 - 5.5V DC voltage can be applied to the main antenna from the VANT pin, obviating the need for an external antenna supply or bias-tee.

Board Dimensions

The board dimensions are illustrated in the drawing below; the listed measurements are in inches.

Need more measurements?

For more information about the board's dimensions, users can download the eagle files for the board. These files can be opened in Eagle and additional measurements can be made with the dimensions tool.

Eagle - Free Download!

Eagle is a CAD program for electronics that is free to use for hobbyists and students. However, it does require an account registration to utilize the software.

Download from

Dimensions Tool

This video from Autodesk demonstrates how to utilize the dimensions tool in Eagle, to include additional measurements:

USB-C Connector

The USB connector is provided to power and interface with the mosaic-X5 GNSS receiver. For most users, it will be the primary method for communicating with the mosaic-X5 module.

Power

The Tri-band GNSS RTK breakout board only requires 5V to power all of the board's components. The simplest method to power the board is through the USB-C connector. Alternatively, the board can be converted to utilize 3.3V for low power applications.

Below, is a general summary of the power circuitry on the board, broken out as PTH pins:

VUSB - The voltage from the USB-C connector, usually 5V.
- Input Voltage Range: 4.4 - 5.5 V
- Power source for the entire board.
  - Powers the 3.3V voltage regulator (AP2112) and the active antenna preamplifier for the mosaic-X5 module. (1)
  - This pin powers the integrated PHY of the mosaic-X5 module's USB interface.
- Features ESD protection and a thermal fuse.
VIN - Alternate input supply voltage for the board.
- Alternative power supply input for the board, excluding the integrated PHY of the USB interface.
- Power source for the entire board.
  - Powers the 3.3V voltage regulator (AP2112) and the active antenna preamplifier for the mosaic-X5 module. (2)
- Features a thermal fuse.
3.3V - Provides a regulated 3.3V from AP2112 using the power from the VIN or VUSB (5V) inputs.
- Input Voltage Range: 3.135 - 3.465 V
- The 3.3V AP2112 LDO regulator can source up to 600mA.
  - Used to power the mosaic-X5 module, SD card slot, and the power LED.
  - The active antenna preamplifier (3) for the mosaic-X5 module can be alternatively powered with 3.3V (see the Jumpers and mosaic-X5 sections).
V_BATT - Always-on power supply
- Input Voltage Range: 3.135 - 3.465 V
- Tied to 3.3V (see the Jumpers section).
  - Used to power the module in Standby mode.
GND - The common ground or the 0V reference for the voltage supplies.

- While the AP2112 LDO regulator has an input voltage range of 2.5 - 6V, a minimum supply voltage of 3.5V is recommended for a 3.3V output.
- A 3 - 5.5V DC voltage can be applied to the main antenna from the VANT pin, obviating the need for an external antenna supply or bias-tee.
- While the AP2112 LDO regulator has an input voltage range of 2.5 - 6V, users should supply:
  - A minimum of 3.5V for a 3.3V output from the regulator
  - A maximum of 5.5V as not to exceed the electrical limitations of the mosaic-X5 module
- A 3 - 5.5V DC voltage can be applied to the main antenna from the VANT pin, obviating the need for an external antenna supply or bias-tee.
A 3 - 5.5V DC voltage can be applied to the main antenna from the VANT pin, obviating the need for an external antenna supply or bias-tee.

VIN Input Voltage

While the AP2112 LDO regulator has an input voltage range of 2.5 - 6V, users should supply:

A minimum of 3.5V for a 3.3V output from the regulator
A maximum of 5.5V as not to exceed the electrical limitations of the mosaic-X5 module

However, users are able to bypass the electrical limitations of the mosaic-X5 module and power the board with up to 6V. Users just need to modify the ANT_V jumper (see the Jumpers section) to the 3V3 pad.

MEAS Pins

These pins can be used to measure the current being drawn through the USB connector or VUSB/VIN pins (see the Jumpers section).

JST Connector

The V pin of the JST connector is designed for an input voltage to VIN. By default, it does not operate as a voltage output.

Bypass - Reverse Current Protection Diode

Danger - Proceed at Your Own Risk!

By bypassing the reverse current protection diode, users should take precautions to ensure that they do not provide an input voltage to the JST connector, when the board is connected to their computer. Otherwise, it may result in damage to the computer's USB bus.

To enable an output voltage on the JST connector, users will need to bypass the protection diode that prevents reverse current to the USB-C connector. This can be done by jumping the VUSB and VIN pins together.

Once jumpered, when the board is powered through the USB-C connector, the V pin of the JST connector will provide an output voltage from the USB-C connector.

Info

For more details, users can reference the schematic and the datasheets of the individual components on the board.

Power Modes

The mosaic-X5 module operates in three different power states.

Off - The module is completely turned off
- When transitioning to the Off state from Active, recent data may not be lost and not logged to the external SD card
Standby - The module is in a low-power consumption mode (1)
- The module power consumption in standby is <5mW
- The PMIC_ON_REQ pin is driven LOW
- The MODULE_RDY pin is in a LOW
- Monitors the state of the ONOFF pin (Not available)
Active - The module is operating with all functions active
- On power up, the module restarts in the configuration stored in the boot configuration file
- The PMIC_ON_REQ pin is driven HIGH
- The MODULE_RDY pin is in a HIGH (2)

Essentially, the same state as Off; except in the transition to the Standby mode, before the module shuts down:
- All logging tasks are terminated
- The SD card is unmounted
- The PMIC_ON_REQ pin is driven LOW
Level becomes HIGH about 300ms after powering up, reset, or waking up from standby

Info

By default, the board is hardwired to operate only in the Active and Off modes.

For more information on the power management of the mosaic-X5 module, please refer to sections 3.4, 3.5, 4.1, and 4.13 of the hardware manual.

Enabling Standby Mode

Users can enable Standby mode on the mosaic-X5, by modifying the V_BATT jumper (see the Jumpers section) and providing an external power source for the V_BATT pin (3.3V). However, because the ONOFF pin isn't exposed users will need to power cycle the board to return to the Active state.

Drive Current - PMIC_ON_REQ/MODULE_RDY

The drive current on the PMIC_ON_REQ and MODULE_RDY pins is low. Enough to be read by a digital pin on a microcontroller, but not high enough to drive an LED.

Power Consumption

The power consumption of the mosaic-X5 module depends on the GNSS signals enabled and the positioning mode. The table below, lists the average power consumption for common configurations. The current listed, is based on a supply voltage of 3.3V.

GNSS Signals	Positioning Mode	Power (mW)	Current (mA)
GPS L1 C/A	Stand-Alone (1Hz)	550	167
GPS L1/L2	RTK (1Hz)	670	203
GPS/GLONASS L1/L2	RTK (1Hz)	695	211
GPS/GLONASS L1/L2+GALILEO L1/E5a +BeiDou B1C/B2a	RTK (1Hz)	850	258
GPS/GLONASS L1/L2+GALILEO L1/E5a +BeiDou B1C/B2a	RTK (100 Hz)	930	282
GPS/GLONASS L1/L2 + L-band	PPP (1Hz)	760	230
All signals from all GNSS constellations	Static (1Hz)	910	276
All signals from all GNSS constellations +L-band	Static(1Hz)	980	297
All signals from all GNSS constellations +L-band	Static (100Hz)	1080	327

Source: mosaic-X5 Hardware Manual

mosaic-X5

The centerpiece of the Tri-band GNSS RTK breakout board, is the mosaic-X5 module from Septentrio. Their mosaic modules are low-power, multi-band, multi-constellation GNSS receivers capable of delivering centimeter-level precision at high update rates. The modules also feature Septentrio's unique AIM+ technology for interference mitigation and anti-spoofing, which ensures their best-in-class reliability and scalable position accuracy.

The mosaic-X5 module on the Tri-band GNSS RTK breakout board.

Features:

Operating Voltage: 3.135 - 3.465V
Operating Temperature: -40 - 85°C
GNSS Support
- GPS: L1C/A, L1PY, L2C, L2P, L5
- GLONASS: L1CA, L2CA, L2P, L3 CDMA
- Beidou: B1I, B1C, B2a, B2b, B2I, B3
- Galileo: E1, E5a, E5b, E5 AltBoc, E6
- QZSS: L1C/A, L1 C/B, L2C, L5
- Navic: L5
- SBAS: Egnos, WA
Antenna Specifications
- Preamplification Range: 15-50dB
- Bias Voltage: 3.0 - 5.5V
- 448 Hardware Channels
Update Rate: 100Hz
Latency: < 10ms

Time to Fix
- Cold Start: < 45s
- Warm: < 20s
- Reacquisition: 1s
Timing Precision: 5ns
Position Accuracy

Correction Horizontal Vertical

RTK 0.6cm (±0.5ppm)
~0.25" 1cm (±1ppm)
~.4"

DGNSS 40cm
~1.3' 70cm
~2.3'

SBAS 60cm
~2' 80cm
~2.6'

Standalone 1.2m
~4' 1.9m
~6.2'

Info

The mosaic-X5 has three power modes: Active, Standby, and Off (see the Power Modes section).

Frequency Bands

The mosaic modules are multi-band, multi-constellation GNSS receivers. Below, are charts illustrating the frequency bands utilized by all the global navigation satellite systems and the ones supported by the mosaic-X5 module.

GNSS frequency bands — Frequency bands of the global navigation satellite systems. (Source: Tallysman)

Info

For a comparison of the frequency bands supported by the mosaic modules, refer to section 3.1 of the hardware manual.

What are Frequency Bands?

A frequency band is a section of the electromagnetic spectrum, usually denoted by the range of its upper and lower limits. In the radio spectrum, these frequency bands are usually regulated by region, often through a government entity. This regulation prevents the interference of RF communication; and often includes major penalties for any interference with critical infrastructure systems and emergency services.

However, if the various GNSS constellations share similar frequency bands, then how do they avoid interfering with one another? Without going too far into detail, the image above illustrates the frequency bands of each system with a few characteristics specific to their signals. Wit these characteristics in mind, along with other factors, the chart can help users to visualize how multiple GNSS constellations might co-exist with each other.

For more information, users may find these articles of interest:

Position Accuracy

The accuracy of the position reported from the mosaic-X5 module, can be improved based upon the correction method being employed. Currently, RTK corrections provide the highest level of accuracy; however, users should be aware of certain limitations of the system:

RTK technique requires real-time correction data from a reference station or network of base stations.
- RTK corrections are signal specific (i.e. an RTK network might provide corrections on only E5b and not E5a).
The range of the base stations will vary based upon the RTK method being employed.
The reliability of RTK corrections are inherently reduced in multipath environments. However, with Septentrio's multipath mitigation technology (APME+) on the mosaic-X5, these errors are significantly reduced when compared to multipath mitigation techniques that modify the correlators in the tracking channels.

Correction	Horizontal	Vertical
RTK	0.6cm (±0.5ppm) ~0.25"	1cm (±1ppm) ~.4"
DGNSS	40cm ~1.3'	70cm ~2.3'
SBAS	60cm ~2'	80cm ~2.6'
Standalone	1.2m ~4'	1.9m ~6.2'

RTK Corrections

To understand how RTK works, users will need a more fundamental understanding of the signal error sources.

Tip

For the best performance, we highly recommend that users configure the module to utilize/provide RTK corrections with a compatible L1/L2/L5 (tri-band) GNSS antenna and utilize a low-loss cable.

Peripherals and I/O Pins

The mosaic-X5 features several peripherals and I/O pins. Some of these are broken out as pins on the Tri-band GNSS RTK breakout board; whereas, others are broken out to their specific interface (i.e. µSD Carsd slot, USB connector, etc.). Additionally, some of their connections are tied to other components on the board.

Interfaces:

4x UART (LVTTL, up to 4 Mbps)
~~Ethernet (RMII/MDIO), 10/100 Mbps~~(1)
USB device (2.0, HS)
SDIO (mass storage)
2x GPIO user programmable
2x Event markers
1x Configurable PPS out

Not available on the Tri-band GNSS RTK breakout board.

SMA Connectors

There are two SMA connectors on the Tri-band GNSS RTK breakout board.

L1/2/5
ActiveAnt

The L1/2/5 ActiveAnt connector is an input for the GPS antenna (see the Antenna section). The connector also provides active power at 5V (see the Jumpers section).

JST pins — The pin connections of the JST connector on the Tri-band GNSS RTK breakout board.

TimePulse

The TimePulse connector provides a PPS output signal (see the PPS Output section).

JST Connector

The Tri-band GNSS RTK breakout features a 6-pin JST GH connector, which is polarized and locking. Users can access the COM3 port of the mosaic-X5 module, through the JST connector with our breadboard cable(1).

Breadboard to JST-GHR-06V Cable - 6-Pin x 1.25mm Pitch
CAB-18079

Pin Connections

When connecting to the board's UART pins, the pins should be connected based upon the flow of their data. For example, when utilizing the Telemetry Radio or the LoRaSerial Kit:

Flow Control — Connection of the UART pins from the LoRaSerial radio to a host system, like the Tri-band GNSS RTK breakout board.

V Pin

By default, the power pin (i.e. V or Pin 1) of the JST connector is connected to VIN and configured as a power input. The board can be modified to configure that pin as a power output; however, the modification would bypass some of the safety features of the board (see the Power section).

SD Card Slot

The µSD card slot allows users easily log and store data on the board.

Initial Configuration

Before data logging can occur, it is necessary to create a logging stream from the Logging tab of the web interface or using the RxTools software suite. Streams can contain NMEA or SBF (Septentrio Binary Format) data; SBF can contain RTCM and/or RINEX. (see the Data Logging section)

SD Card Specifications

The mosaic-X5 module is only compatible with SD cards of up to 32GB, formatted with a FAT32 file system.

Standby Mode

When Standby mode is initialized, the module terminates all running processes and unmounts the external SD card to avoid any log file corruption (see the Power Modes section).

LOG Button

Data logging can be controlled with the LOG button (see the Log Button section).

Pressing the LOG button (< 5s) toggles data logging to the SD card on and off.
Holding the LOG button for more than 5 seconds (> 5s) and then releasing it, will force the board to:
- Unmount the SD card if it was mounted
- Mount the SD card if it was unmounted

LOG Status LED

The SD card mount status is indicated on the LOG LED andLOG_L pin (see the Status LEDs section).

LED	Pin	Status
Off	Low	SD card not present or unmounted
On	High	SD card present and mounted
Blinking	Pulses	Data logging activity

Status LEDs

There are five status LEDs on the TMC6300 motor driver:

PWR - Power (Red)
- Turns on once power is supplied through the USB-C connector or VIN connections
PPS - Pulse-Per-Second (Yellow)
- Indicates when there is a pulse-per-second signal (see the PPS Output section)
LOG - Data Logging (Green)
- Indicates data logging activity (see the SD Card Slot section)
  - Off - SD card not present or unmounted
  - On - SD card present and mounted
  - Blinking - Data logging activity
PVT - Position/Velocity/Time Solution (Blue)
- Turns on when a PVT solution is available
RTK - RTK Mode (White)
- Controlled through GPIO 02

The status indicator LEDs on the Tri-band GNSS RTK breakout board.

Buttons

There are two buttons on Tri-band GNSS RTK breakout board: RST and LOG buttons.

Reset Button

The RST (reset) button allows users to reset the mosaic-X5 module without unplugging the board.

Log Button

The LOG button allows users easily control the data logging feature and the µSD card, without having to configure the module.

Pressing the LOG button (< 5s) toggles data logging to the SD card on and off.
Holding the LOG button for more than 5 seconds (> 5s) and then releasing it, will force the board to:
- Unmount the SD card if it was mounted
- Mount the SD card if it was unmounted

SD Card Status

The SD card mount status is indicated on the LOG LED andLOG_L pin (see the Status LEDs section).

LED	Pin	Status
Off	Low	SD card not present or unmounted
On	High	SD card present and mounted
Blinking	Pulses	Data logging activity

Jumpers

Never modified a jumper before?

Check out our Jumper Pads and PCB Traces tutorial for a quick introduction!

How to Work with Jumper Pads and PCB Traces

There are nine jumpers on the back of the board that can be used to easily modify the hardware connections on the board.

PowerLED PowerPPS Signal

MEAS

This jumper can be cut and used to measure the current consumption of the board from the VUSB and/or VIN power supply inputs.

V_BATT

This jumper can be cut to disconnect the VBATT pin from the 3.3V output of the AP2112 LDO regulator.

Info

The VBATT pin is the power input for the mosaic-X5 module, when it is in Standby mode. Therefore, it also determines the power state of the mosaic-X5 module, when power is disconnected from the VUSB and VIN inputs.

By default, the jumper connected and the VBATT pin is powered at 3.3V. When the primary power is disconnected, the mosaic-X5 module will enter Standby mode.
If cut, the VBATT pin will be disconnected from the 3.3V output of the AP2112 LDO regulator. When the primary power is disconnected the VUSB and VIN inputs, the mosaic-X5 module will shut off.

ANT_V

This jumper can be modified to control the output voltage of the active antenna connection.

Info

By default, the middle pad is connected to the 5V pad, which draws power from the VUSB and/or VIN inputs.

Users can modify the jumper, to configure the output voltage of the active antenna connection to 3.3V, by cutting the jumper and connecting the middle pad to the 3V3 pad.

There are five jumpers that control power to the status LEDs on the board.

Info

By default, all the jumpers are connected, to power the status LEDs. For low power applications, users can cut the jumpers to disconnect power from each of the LEDs.

PWR_LED - This jumper can be cut to remove power from the red, power LED.
PPS_LED - This jumper can be cut to remove power from the yellow LED, which is connected to the PPS signal.
LOG_LED - This jumper can be cut to remove power from the green LED, which indicates if data is being logged to the SD card.
GP_LED - This jumper can be cut to remove power from the blue LED that is connected to the general purpose pins.
RTK_LED - This jumper can be cut to remove power from the white LED, indicating RTK corrections.

The jumper next to the PPS pin can be cut to disconnect the pulse per second signal from the PTH pin.

Info

By default, PPS signal is connected to the PPS pin.