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Hardware Overview

Danger

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. For example, users can utilize the iFixit Anti-Static Wrist Strap.

QR code to product video

Active Antenna

Never inject an external DC voltage with the GNSS 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.

Introduction

This SparkPNT GNSS Flex module features the Septentrio mosaic-X5, a compact, ultra-low power, multi-band, multi-constellation, high-precision GNSS receiver. The receiver supports the GPS (USA), GLONASS (Russia), Beidou (China), Galileo (Europe), and NavIC (India) constellations, including regional systems (i.e. SBAS and QZSS). With its Real Time Kinematics (RTK) capabilities, the module can achieve a horizontal accuracy of 6mm (~0.25in), vertical accuracy of 1cm (~0.4in) using RTK, and timing precision of 5ns (5 billionths of a second). It also features Septentrio's unique AIM+ technology for interference mitigation and anti-spoofing, ensuring best-in-class reliability and scalable position accuracy.

The mosaic-X5 is a sophisticated module with an internal web server that can be utilized with any web browser. On the GNSS Flex module, the web server is accessed through either the USB data pins from the standard GNSS Flex headers; or the Ethernet PHY of the mosaic-X5, which is broken out on an third 2x10 pin, 2mm pitch female header. To guide users through the configuration options, Septentrio provides dozens of video tutorials about the web interface.

For the users who prefer a command-line interface, Septentrio has you covered. Users can still control and configure the mosaic-X5 module through a CLI, which is useful for scenarios such as production line testing (in fact, that is how we test this board) or remote access.

mosaic-X5 Product Comparison

Below is a simple comparison table between our mosaic-X5 GNSS products and Septentrio's development and evaluation kits:

mosaic-X5 Development Kit
Product Thumbnail
mosaic-go Evaluation Kit
Product Thumbnail
mosaic-X5 GNSS Breakout
Product Thumbnail
RTK mosaic-X5
Product Thumbnail
mosaic-X5 Flex Module
Product Thumbnail
GNSS Antenna Dual Single (mosaic-X5)
Dual (mosaic-H) 		Single Single Single
USB Connector micro-B micro-B Type-C Type-C N/A*
Ethernet Yes
10/100 Base-T 		No No Yes
10/100 Base-T 		2x10 Header*
WiFi No No No Yes - Network Bridge
10 Base-T 		No
COM Ports 4 2 4 1 - mosaic-X5
1 - ESP32 		4
µSD Card Slot Yes Yes Yes Yes 2x10 Header*
Reset/Log Buttons Yes No* Yes Yes No
Logic-Level 1.8V
3.3V 		3.3V 3.3V 3.3V
5V 		3.3V
PPS Signal Header Pin 6-Pin JST Connector SMA Connector Screw Terminal 2x10 Header*
Enclosure Material N/A Metal N/A Aluminum N/A
Dimensions N/A 71 x 59 x 12mm ± 1mm 70.9 x 50.8 x 8mm 180.6 x 101.8 x 41mm
Enclosure Only
Weight N/A 58g ± 1g 22.6g 415.15g
Enclosure Only

mosaic-go Evaluation Kit

The reset pin is exposed on 4-pin JST connector and the log pin is connected to the latch pin of the SD card slot.

mosaic-5 Flex Module

SparkPNT GNSS Flex modules are modular, plug-in boards that utilize a carrier board to access the pins of the GNSS Flex headers.

Design Files

  • Design Files

  • Download the *.step File

    Manipulate 3D Model
    Controls Mouse Touchscreen
    Zoom Scroll Wheel 2-Finger Pinch
    Rotate Left-Click & Drag 1-Finger Drag
    Move/Translate Right-Click & Drag 2-Finger Drag

    Board Dimensions
    Dimensions of the mosaic-X5 GNSS Flex module.

    Need more measurements?

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

    KiCad - Free Download!

    KiCad is free, open-source CAD program for electronics. Click on the button below to download their software. (*Users can find out more information about KiCad from their website.)

    Download

    📏 Measuring Tool

    This video demonstrates how to utilize the dimensions tool in KiCad, to include additional measurements:

    QR code to play video

Board Layout

The GNSS Flex system is designed around two 2x10-pin, 2mm pitch headers used mate the two types of boards. A standardized pin layout, keeps the ecosystem pin-compatible for upgrades and allows board to be easily swapped for repairs. Depending on the capabilities of the GNSS receiver, these pins will breakout the UART (x4), I2C, and SD card interfaces along with any PPS or event signals of the GNSS receiver.

The mosaic-X5 GNSS Flex module has the following features:

Board Layout

Layout of the major components on the mosaic-X5 GNSS Flex module.

  1. mosaic-X5 GNSS Receiver
    The Septentrio mosaic-X5 GNSS receiver
  2. GNSS Flex Headers
    Two sets of 2x10 pin, 2mm pitch female headers for connecting a GNSS Flex module to carrier boards
  3. Ethernet PHY Header
    A 2x10 pin, 2mm pitch female header that breaks out the Ethernet PHY pins of the mosaic-X5
  4. ANT1 U.FL Connector
    An U.FL connector for attaching an external GNSS antenna

mosaic-X5 Module

The centerpiece of the mosaic-X5 GNSS Flex module, 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.

![QR code to product video](./assets/img/qr_code/video-septentrio_mosaic-x5.png){ .qr width=100 }
  • mosaic-X5 module
    The mosaic-X5 module on the mosaic-X5 GNSS Flex module.

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).

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)
  1. 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
  2. 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](./assets/component_documentation/mosaic_hardware_manual_v1.9.0.pdf)*

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.

Supported frequency bands

The frequency bands supported by the mosaic-X5 GNSS receiver.

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.

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

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](https://en.wikipedia.org/wiki/Real-time_kinematic_positioning "Real-Time Kinematic") | **0.6cm** *(±0.5ppm)*
~0.25" | 1cm *(±1ppm)*
~.4" | | [DGNSS](https://en.wikipedia.org/wiki/Differential_GPS "Differential GNSS") | 40cm
~1.3' | 70cm
~2.3' | | [SBAS](https://en.wikipedia.org/wiki/GNSS_augmentation "Satellite-Based Augmentation System") | 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/L6 GNSS antenna and utilize a low-loss cable.

GNSS Flex Headers

The GNSS Flex system is designed around two 2x10-pin, 2mm pitch headers used mate the two types of boards. A standardized pin layout, keeps the ecosystem pin-compatible for upgrades and allows boards to be easily swapped for repairs. Depending on the capabilities of the GNSS receiver, these pins will breakout the UART (x4), I2C, and SD card interfaces along with any PPS or event signals of the GNSS receiver.

Peripherals and I/O pins

The peripherals and I/O pins on the mosaic-X5 GNSS Flex module.

Below, are the features that are available from the mosaic-X5 GNSS receiver.

Supported 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 (2)
  • 2x LED outputs
  • 2x Event markers
  • 1x Configurable PPS out
  1. Broken out on the extra middle header
  2. Not available on the mosaic-X5 GNSS Flex module.

For most users, this will be the primary interface for the mosaic-X5 module.

USB interface
USB-C connector on the mosaic-X5 GNSS Flex module.

  • When a module is initially connected to a computer, the board will initialize as a USB mass storage device.
    • For Windows PCs, the USB driver (1) can be installed from the mass storage device or the RxTools software suite.
    • When the SD card is mounted, this drive will contain the contents of the SD card that is inserted on the board.
  • Once the USB driver is installed:
    • Two virtual COM ports are emulated, which can be used as standard COM ports to access the receiver.
    • This interface will support Ethernet-over-USB.
      • By default, the receiver is not allowed to access the Internet over USB.
      • The IP address allocated to the Ethernet-over-USB interface is 192.168.3.1.
        • The IP address cannot be changed; therefore, only single receiver should be connected to your computer at a time.
  1. On Linux, the standard Linux CDC-ACM driver is suitable.

The mosaic-X5 has four UARTs ports, which can be operated and configured separately.

UART interface
The UART ports on the mosaic-X5 GNSS Flex module.

  • COM ports 1-3 feature flow control pins, which are disabled by default.
  • These ports also support a point-to-point protocol server, by which it can accept TCP/IP connections over a serial link.

Default Configuration

By default, the UART ports are configured with the following settings:

  • Baudrate: 115200bps
  • Data Bits: 8
  • Parity: No
  • Stop Bits: 1
  • Flow Control: None

From the module, the PPS output signal's logic-level is 1.8V. However, for the convenience of users, we have added a buffer and bumped up the signal's logic-level to 3.3V on the mosaic-X5 GNSS Flex module.

I/O for PPS signal
The PPS signal's output on the mosaic-X5 GNSS Flex module.

Use Case
  • Users could use this signal in conjunction with the event pins to synchronize two mosaic-X5 modules with each other.
  • Users could use this signal to create their own Stratum 0 source for the NTP on a primary time server.

The data logging functionality of the board can be configured through the software/web interfaces.

Data logging components
The data logging peripherals on the mosaic-X5 GNSS Flex module.

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).

The mosaic-X5 module features two general purpose, output LED pins. These pins have a maximum output current of 10 mA and output impedance of 20Ω.

LED pins
The LED pins on the mosaic-X5 GNSS Flex module.

The mosaic-X5 module features two general purpose, event input pins. These pins can be used to time tag external events with a time resolution of 20ns.

General use pins
The event pins on the mosaic-X5 GNSS Flex module.

Tip

For example, these pins can be used in conjunction with the PPS output signal for time syncing.

Extra Header

In addition to the GNSS Flex headers, an extra 2x10 pin, 2mm pitch female header is populated between them. This header breaks out the Ethernet PHY interface, along with a few other operation indication signals.

Miscellaneous pins

The JST connector on the mosaic-X5 GNSS Flex module.

  • RMII Interface
    The module supports an Ethernet PHY through its RMII interface. An up-to-date list of supported PHY's can be found in Septentrio’s Knowledge Base.
  • PMIC_ON Pin
    The state of PMIC pin indicates when the subsystems are energized and ready (see the Power Modes section).
  • READY Pin
    The RDY pin indicates the operational mode of the mosaic-X5 module (see the Power Modes section). The level is high when module is operating, and low when in standby or reset.
  • ON_OFF Pin
    The RDY pin indicates the operational mode of the mosaic-X5 module (see the Power Modes section). The level is high when module is operating, and low when in standby or reset.

U.FL Connector

Users will need to connect a compatible GPS antenna to the ANT1 U.FL connector. The type of antenna used with the mosaic-X5 module affects the overall accuracy of the positions calculated by the GNSS receiver.

  • An active antenna often features a LNA. This allows the module to boost the signal received by the GNSS module without degrading the SNR.
  • The more bands an antenna supports, the greater the performance.
    • Faster acquisition time.
    • Access and support for the L5 GPS band can potentially mitigate multi-path errors.
    • Supporting more frequency bands, allows a GNSS receiver to be less susceptible to jamming and spoofing.

Tip

For the best performance, we recommend users choose a compatible L1/L2/L5/L6 GNSS antenna and utilize a low-loss cable.

There are some key parameters related to an antenna that can make or break the signal reception from the satellites. These include the operation frequency, gain, polarization, efficiency and overall loss.

GPS antenna input

The U.FL connector to attach an external GNSS antenna to the mosaic-X5 GNSS Flex module.

Info

The VANT pin provides 3.3V of external power for an active antenna.

Danger

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.

Jumpers

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

Jumpers

The jumpers on the back of the mosaic-X5 GNSS Flex module.

Never modified a jumper before?

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

  • 2V8
    This jumper can be cut to disconnect power to the internal 10MHz TXCO.
  • REF
    This jumper can be cut to disconnect the 10MHz reference signal from the internal TXCO.

Jumpers signals

The signals from the mosaic-X5 module to the jumpers on the board.