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Hardware Overview

Important: Read Before Use!

ESD Sensitivity

The mosaic-G5 P3 GNSS receiver 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.

Info

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

  • The All-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 and BlueSMiRF header pins
  • The mosaic-G5 P3 GNSS receiver features internal ESD protection to the ANT_1 antenna input.

Active Antenna

Never inject an external DC voltage into the SMA connector for the GNSS antenna, as it may damage the mosaic-G5 P3 GNSS receiver. 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.

Design Files

  • Design Files

  • 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-G5 P3 GNSS breakout board.

    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.)

    📏 Measuring Tool

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

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Board Layout

The SparkFun Allband GNSS RTK Breakout - mosaic-G5 P3 features the following:

Layout

Layout of the major components on the breakout board.

  1. USB-C Connector
    The primary inteface for powering and interacting with the board
  2. mosaic-G5 P3 GNSS Receiver
    The Septentrio mosaic-G5 P3 GNSS receiver
  3. Header Pins
    Exposes pins to power the board and breaks out the interfaces of the mosaic-G5 P3 GNSS receiver
  4. BlueSMiRF Header Pins
    Exposes the UART2 interface of the mosaic-G5 P3 GNSS receiver
  5. JST Connector
    Exposes the UART2 interface of the mosaic-G5 P3 GNSS receiver
  6. Status LEDs
    LED status indicators for the mosaic-G5 P3 GNSS receiver
  7. Antenna L1/2/5/6 RF Connectors
    SMA and U.FL (optional) connectors for an external GNSS antenna

USB-C Connector

The USB connector is provided to power and interface with the mosaic-G5 P3 GNSS receiver. For most users, it will be the primary method for communicating with the GNSS receiver.

USB-C Connector

USB-C connector on the All-band GNSS RTK breakout board.

Power

The All-band GNSS RTK breakout board only requires 3.3V 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 also be powered through the VIN pin.

Power connections

All-band GNSS RTK breakout board's power connections.

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
  • VIN - Alternate input supply voltage for the board
    • Input Voltage Range: 1.2 - 5.5V (1)
    • Power source for the entire board
  • 3V3 - Provides a regulated 3.3V from the RT9080, using the power supplied from the VIN pin or USB-C connector
    • Used to power the mosaic-G5 P3 GNSS receiver and its active antenna preamplifier, the LEDs, and the power pin of the JST connector and BlueSMiRF header
    • Controlled by the EN pin, which is enabled by default
  • EN - Enables the voltage output from the RT9080, 3.3V voltage regulator
    • Enabled by default (active HIGH)
  • RST - Used to reset the mosaic-G5 P3 GNSS receiver
    • Connected to the nRST_IN input-only pin with an internal pull-up resistor
    • Driving the pin LOW triggers the restart of the mosaic-G5 P3 GNSS receiver
  • GND - The common ground or the 0V reference for the voltage supplies.
  1. While the RT9080 LDO regulator has an input voltage range of 1.2 - 5.5V, a minimum supply voltage of 3.5V is recommended for a 3.3V output.

JST Connector

The VSEL pin of the BlueSMiRF header and + pin of the JST connector are designed to operate as a voltage output. An input voltage can be supplied through these pins; however, users should be mindful of any voltage contention issues. Additionally, users can modify the VSEL jumper to change the output voltage level of these pins.

Info

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

Power Consumption

The power consumption of the mosaic-G5 P3 GNSS receiver 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 Power (mW) Current (mA)
GPS/GLONASS L1/L2 440 133
All signals from all GNSS constellations 570 173
All signals from all GNSS constellations +L-band 670 203

Source: mosaic-G5 P3 Hardware Manual

  mosaic-G5 P3

The centerpiece of the All-band GNSS RTK breakout board, is the mosaic-G5 P3 GNSS receiver from Septentrio. Their mosaic-G5 P3 modules are low-power, multi-band, multi-constellation GNSS receivers capable of delivering centimeter-level precision in a small form factor without compromising on performance. They provide strong positioning reliability in challenging environments and are tailored for applications such as delivery or light show drones. It also features Septentrio's unique AIM+ technology for interference mitigation and anti-spoofing, which ensures their best-in-class reliability and scalable position accuracy.

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  • mosaic-G5 P3 GNSS receiver
    The mosaic-G5 P3 GNSS receiver on the All-band GNSS RTK breakout board.

Features:

  • Operating Voltage: 3.135 - 3.465V
  • GNSS Support
    • GPS: L1C/A, L1C, L2C, L2PY, L5
    • GLONASS: L1CA, L2CA, L2P, L3 CDMA
    • Beidou: B1I, B1C, B2a, B2b, B2I, B3I
    • Galileo: E1, E5a, E5b, E6
    • QZSS: L1C/A, L1 C/B, L2C, L5, L6
  • Time to Fix
    • Cold Start: < 35s
    • Warm: < 10s
    • Reacquisition: 1s

  • Position Accuracy

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


  • Update Rate: 20Hz
  • Latency: < 10ms
  • Event Accuracy: < 3ns
  • Interfaces:
    • UART (x2)
    • USB device (2.0, HS)
    • GPIO user programmable (x2)
    • Event markers (x2)
    • Configurable PPS out (x2)
  • Protocols:
    • Septentrio Binary Format (SBF)
    • NMEA 0183, v2.3, v3.03, V4.0
    • RTCM v3.x (MSM included)
  • Antenna Specifications
    • Preamplification Range: 15-50dB
    • Bias Voltage: 3.0 - 5.5V
    • 789 Hardware Channels
  • Operating Temperature: -40 - 85°C
  • Package Size: 16.4mm x 22.8mm x 2.4mm
  • Weight: 2.2g

Tip

The capabilities of each receiver is defined by a the optional features that are enabled. The capabilities of the receiver depend on a combination of the hardware model and version, the firmware version, and the set of permissions enabled for the optional features. Permissions are further explained in section 1.17. The command getReceiverCapabilities will list the receiver's capabilities. Otherwise, using RxControl (go to Help > Receiver Interface > Permitted Capabilities).

Frequency Bands

The mosaic GNSS receivers 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-G5 P3 GNSS receiver.

Supported frequency bands

The frequency bands supported by the mosaic-G5 P3 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 GNSS receivers, 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-G5 P3 GNSS receiver, 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-G5 P3, 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'
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 GNSS receiver to utilize/provide RTK corrections with a compatible L1/L2/L5/L6 (All-band) GNSS antenna and utilize a low-loss cable.

Peripherals and I/O Pins

The mosaic-G5 P3 features several peripherals and I/O pins. Some of these are broken out as pins on the All-band GNSS RTK breakout board; whereas, others are broken out to their specific interface (i.e. USB connector, etc.). Additionally, some of their connections are tied to other components on the board.

Peripherals and I/O pins

The peripherals and I/O pins on the All-band GNSS RTK breakout board.

Interfaces:

  • USB device (2.0, HS)
  • 2x UART (LVTTL, up to 4 Mbps)
  • 2x GPIO user programmable
  • 2x Event markers
  • 2x Configurable PPS out

For most users, this will be the primary interface for the mosaic-G5 P3 GNSS receiver.

USB interface
USB-C connector on the All-band GNSS RTK breakout board.

Info

When a GNSS receiver is initially connected to a computer, two virtual COM ports are emulated. These can be used as standard COM ports to communicate with the GNSS receiver.

The mosaic-G5 P3 has two dedicated UART interfaces. Each of the UART ports can be configured and operated separately.

UART interface
The UART ports on the All-band GNSS RTK breakout board.

Info

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

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

The COM port settings are set with the setCOMSettings command.

UART2

The UART2 or COM2 interface features flow control pins, which are disabled by default. The interface can also be accessed through the JST connector and/or BlueSMiRF header.

Bus Contention

To avoid bus contention issues, make sure only one device is connected to any of these options.

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 All-band GNSS RTK breakout board.

The 3.3V PPS signals can be access through the PPSx pins. The polarity, frequency, and pulse width of these signals can be configured with the setPPSParameters and setPPS2Parameters commands.

I/O for PPS signal
The PPS signal outputs on the All-band GNSS RTK breakout board.

Info

During module startup, these pins are first in high-Z mode for about 1s. Then they are driven low for another second before being driven to the intended user-selected level about 2s after powering up the module.

GPIO Pins

It is possible to use these pins as general-purpose I/O pins, but their maximum current limited to 8mA.

PPS1 LED

The PPS1 signal is connected to the PPS LED, to be used as a visual indicator. There is also PPS1 jumper attached to the PPS LED. For low power applications, the jumper can be cut to disable the PPS LED.

The mosaic-G5 P3 GNSS receiver features two general purpose I/O pins. These pins have a maximum output current of 16 mA and pulled-up by default. These pins are also connected to the GPIO1 and GPIO2 status LEDs, whose function (level or LED status indicator) can be programmed with the setGPIO1Mode and setGPIO2Mode commands.

General use pins
The GPIO pins and LEDs on the All-band GNSS RTK breakout board.

Along with its polarity, the output signal from these pins can be used to indicate one of the following status modes:

  • PVTLED: LED lights when a PVT solution is available.
  • RTKLED: LED is off if the PVT is not in RTK mode, blinks in float RTK and is solid on in fixed RTK.
  • TRACKLED: Tracked satellite indicator.
  • DIFFCORRLED: Differential correction indicator.
    • In rover PVT mode, this LED reports the number of satellites for which differential corrections have been provided in the last received differential correction message (RTCM or CMR).
    • If the corrections are received from geostationary satellites over the L-band, the LED will be on for about 1 second, then blink fast twice.

Info

By default, these pins are configured in input mode with pull-up. Also, for about 2 seconds after powering or resetting the module, these pins are in input mode (pulled up) regardless of the user configuration stored in the boot configuration file.

LED Jumpers

There are jumpers attached to the GPIOx LEDs. For low power applications, the jumpers can be cut to disable their respective LED.

The mosaic-G5 P3 GNSS receiver features two event input pins, which can be used to time tag external events with a time resolution of 3ns. Use the setEventParameters command to configure these pins.

General use pins
The event pins on the All-band GNSS RTK breakout board.

Tip

To properly detect event triggers:

  • There must be a minimum of 5ms between two events on the same EVENTx pin
  • There must be no more than 20 events in any interval of 100ms, on all the EVENTx pins

BlueSMiRF Header

The All-band GNSS RTK breakout features a 6-pin BlueSMiRF PTH header that is compatible with may of our serial devices (i.e. UART adapters, serial data loggers,BlueSMiRF v2 Bluetooth® serial link, and microcontrollers). Users can access the UART2 interface of the mosaic-G5 P3 GNSS receiver through the BlueSMiRF header pins.

BlueSMiRF header

The 6-pin BlueSMiRF PTH header on the All-band GNSS RTK breakout board.

Info

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

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

The COM port settings are set with the setCOMSettings command.

UART2

The UART2 or COM2 interface features flow control pins, which are disabled by default. The interface can also be accessed through the JST connector and/or PTH pins.

Bus Contention

To avoid bus contention issues, make sure only one device is connected to any of these options.

VSEL Pin

By default, the power pin (i.e. VSEL or Pin 4) of the BlueSMiRF header is connected to 3.3V and configured as a power output. An input voltage can be supplied through the pin; however, users should be mindful of any voltage contention issues.

Jumper

By default, the VSEL jumper is connected to 3V3 pad for a regulated 3.3V output. However, users can modify the jumper to utilize the voltage supplied from either the USB or VIN inputs.

JST Connector

The All-band GNSS RTK breakout features a 4-pin JST GH connector, which is polarized and locking. Users can access the UART2 interface of the mosaic-G5 P3 GNSS receiver through the JST connector. The JST connector is compatible with external devices, such as the SiK Telemetry Radio V3 for RTK corrections using one of our JST adapter cables.

JST connector

The JST connector on the All-band GNSS RTK breakout board.

Info

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

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

The COM port settings are set with the setCOMSettings command.

UART2

The UART2 or COM2 interface features flow control pins, which are disabled by default. The interface can also be accessed through the BlueSMiRF header and/or PTH pins.

Bus Contention

To avoid bus contention issues, make sure only one device is connected to any of these options.

Pin Connections

When connecting the All-band GNSS RTK breakout board to other products, users need to be aware of the pin connections between the devices. and voltage ranges of the products. Below, is a table of the pin connections for the JST connector on the All-band GNSS RTK breakout board.

JST pins
The pin connections of the JST connector.

Pin Number 1
(Left Side) 		2 3 4
(Right Side)
Label + T R -
Function Voltage Output
- Default: 3.3V
- Selectable: 3.3V or 5V 		UART2 - Transmit UART2 - Receive Ground

As documented in the LoRaSerial product manual, the pin connections between a host system and the LoRaSerial Kit radio is outlined in the image below.

Flow Control
The COM ports on the All-band GNSS RTK breakout board.

When connecting the All-band GNSS RTK breakout board to our radios, only the RX, TX, and GND connections are required as outlined in the table below. By default, flow control is disabled and the connections are unnecessary.

Board RX TX GND
Radio TX RX GND

VSEL Pin

By default, the power pin (i.e. + or Pin 1) of the JST connector is connected to 3.3V and configured as a power output. An input voltage can be supplied through the pin; however, users should be mindful of any voltage contention issues.

Jumper

By default, the VSEL jumper is connected to 3V3 pad for a regulated 3.3V output. However, users can modify the jumper to utilize the voltage supplied from either the USB or VIN inputs.

External Antenna

The All-band GNSS RTK breakout board has two options for connecting an external GNSS antenna; the Antenna L1/2/5/6 U.FL and SMA connectors. These inputs are DC-biased and ESD-protected, so an active antenna can directly be connected without additional components. By default, the SMA connector is the primary interface. In order to utilize the U.FL connector, the RF jumper must be modified to redirect the signal path from the SMA connector.

GNSS antenna input

The SMA and U.FL connectors to attach a GNSS antenna to the All-band GNSS RTK breakout board.

Users will need to connect a compatible GNSS antenna to the Antenna L1/2/5/6 connector. The type of antenna used with the mosaic-G5 P3 GNSS receiver affects the overall accuracy of the positions calculated by the GNSS receiver.

  • An active antenna often features a LNA. This allows the GNSS receiver to boost the signal received by the GNSS receiver 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.

There are other key parameters related to an antenna that can make or break the signal reception from the satellites. These include, but are not limited to the operation frequency, gain, polarization, efficiency and overall loss.

Tip

For the best performance, we recommend users choose a compatible L1/L2/L5/L6 active GNSS antenna and utilize a low-loss cable. Also, don't forget that GNSS signals are fairly weak and can't penetrate buildings or dense vegetation. The GNSS antenna should have an unobstructed view of the sky.

Info

The VANT pin of the GNSS receiver provides external power for an active antenna. By default, this supply voltage is configured at 3.3V.

Danger

Never inject an external DC voltage into the RF connection for the GNSS antenna, as it may damage the mosaic-G5 P3 GNSS receiver. 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.

Status LEDs

Status LEDs

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

There are four status LEDs on the All-band GNSS RTK breakout board:

  • PWR - Power (Red)
    • Turns on once power is supplied through the USB-C connector or VIN connections
  • PPS1 - Pulse-Per-Second (Yellow)
    • Indicates the pulse-per-second signal from the PPS1 output (see the PPS Output section)
  • GPIO1 (Blue) and GPIO2 (White)

    • These LEDs are controlled through the GPIO pins and operate based on configured mode

      LED Behavior

      The GPIO1andGPIO2LEDs will operate based on the following status modes, which are programmed with thesetGPIO1ModeandsetGPIO2Mode` commands.

      • PVTLED: LED lights when a PVT solution is available.
      • RTKLED: LED is off if the PVT is not in RTK mode, blinks in float RTK and is solid on in fixed RTK.

      • TRACKLED: Tracked satellites indicator.

        LED Behaviour Number of Satellites in Tracking
        Blinks fast and continuously
        (10 times per second)        		 0
        Blinks once, then pauses 1-2
        Blinks twice, then pauses 3-4
        Blinks 3 times, then pauses 5-6
        Blinks 4 times, then pauses 7-8
        Blinks 5 times, then pauses 9+

      • DIFFCORLED: Differential correction indicator.

        • In rover PVT mode, this LED reports the number of satellites for which differential corrections have been provided in the last received differential correction message (RTCM or CMR).

          LED Behaviour Number of Satellites w/ Corrections
          LED Off No differential correction message received
          Blinks fast and continuously
          (10 times per second)          		 0
          Blinks once, then pauses 1-2
          Blinks twice, then pauses 3-4
          Blinks 3 times, then pauses 5-6
          Blinks 4 times, then pauses 7-8
          Blinks 5 times, then pauses 9+

        • If the corrections are received from geostationary satellites over the L-band, the LED will be on for about 1 second, then blink fast twice.

Jumpers

Never modified a jumper before?

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

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

Jumpers

The jumper on the top of the All-band GNSS RTK breakout board.

Jumpers

The jumpers on the back of the All-band GNSS RTK breakout board.

RF
This jumper can be modified to configure the RF input, for the external GNSS antenna, between the SMA and U.FL connectors.

Info

By default, the jumper is configured to utilize the SMA connector.

VSEL

This jumper can be modified to configure/disconnect the VCC pin of the 4-pin locking JST connector and BlueSMiRF header to/from 3V3 or 5V power.

Info

By default, the jumper is configured to supply 3.3V from the All-band GNSS RTK breakout board.

SHLD
This jumper can be cut to disconnect the shield of the USB-C connector from the board's ground plane.

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

  • PWR - This jumper can be cut to remove power from the red, power LED.
  • PPS1 - This jumper can be cut to remove power from the yellow LED, which is connected to the PPS signal.
  • GPIO2 - This jumper can be cut to remove power from the white LED that is connected to the GPIO2 pin.
  • GPIO1 - This jumper can be cut to remove power from the blue LED that is connected to the GPIO1 pin.

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.

VREF

Controls the reference voltage for the internal TXCO

  • In - Voltage input for the internal TXCO
  • Out - Reference voltage to power the internal TXCO
REF

Controls the reference clock signal

  • In - Reference clock signal input
  • Out - 10-MHz signal from the internal TCXO