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Hardware Overview

Important: Read Before Use!

ESD Sensitivity

The mosaic-T 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 ESD precautions to avoid damaging their module.

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Active Antenna

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

External Reference Clock

If the switch for an external reference clock is enabled, users must provide a 10MHz input signal. Otherwise, the mosaic-T module will cease to operate, without a clock signal.

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-T Timing 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 Timing GNSS Breakout - mosaic-T 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. 6-Pin JST Connector
    A UART interface for the mosaic-T GNSS module
  3. µSD Card Slot
    An SD card slot for data logging
  4. LOG Button
    A button to mount the SD card and intialize the data logging stream
  5. mosaic-T GNSS Module
    The Septentrio mosaic-T GNSS module
  6. Status LEDs
    LED status indicators for the mosaic-T GNSS module
  7. SMA Connectors
    • L1/L2/L5/L: The input for a GNSS antenna
    • EXT REF: The input for an external reference clock signal
  8. INT/EXT Switch
    Used to switch between an internal or external refernce clock signal for the mosaic-T GNSS module. If switched to EXT, an external 10MHz signal must be provided for the GNSS module to function

USB-C Connector

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

USB-C Connector

USB-C connector on the mosaic-T Timing GNSS breakout board.

Windows OS

For Windows computers, users will need to install the USB driver before they can interact with the mosaic-T GNNS module.

Info

For more details about this interface, please refer to the USB-C Connector section below.

Power

The simplest method to power the board is through the USB-C connector. However, the mosaic-T Timing GNSS breakout board only requires 3.3V to power most of its components(1), which can be supplied though JST connector or PTH pins.

  1. 5V is only required to utilize the USB interface; and when enabled, it can also power the JST connector.

Power connections

mosaic-T Timing GNSS 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: 2.2 - 5.5 V
    • Power source for the entire board.
      • Powers the 3.3V voltage regulator (AP7361C) and when enabled, it can also power the JST connector. (1)
      • This pin powers the integrated PHY of the mosaic-T module's USB interface.
  • VIN - Alternate input supply voltage for the board.
    • Input Voltage Range: 2.2 - 6 V
    • Alternative power supply input for the board, excluding the integrated PHY of the USB interface.
      • Powers the 3.3V voltage regulator (AP7361C) and when enabled, it can also power the JST connector. (2)
  • 3V3 - Provides a regulated 3.3V from AP7361C using the power from the VIN or VUSB (5V) inputs.
    • Input Voltage Range: 3.135 - 3.465 V
    • The 3.3V AP7361C LDO regulator can source up to 1A.
      • Used to power the mosaic-T module, SD card slot, power LED, and the active antenna preamplifier for the mosaic-T module.
  • VBATT - 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.
  1. While the AP7361C LDO regulator has an input voltage range of 2.2 - 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-T module
  2. While the AP7361C LDO regulator has an input voltage range of 2.2 - 6V, a minimum supply voltage of 3.5V is recommended for a 3.3V output.

JST Connector

The V pin of the JST connector is designed to operate as a voltage output. However, an input voltage can be supplied through the connector, but users should be mindful of any voltage contention issues.

Info

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

Power Modes

The mosaic-T module operates in three different power states, which

Power management pins

The power management pins of the mosaic-T Timing GNSS breakout board.

  • 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 pin is driven LOW
    • The RDY pin is in a LOW
    • When the ON OFF pin is driven LOW for at least 50ms, the module toggles between its Standby and Active states
  • 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 pin is driven HIGH
    • The 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 pin is driven LOW
  2. Level becomes HIGH about 300ms after powering up, reset, or waking up from standby

Info

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

Drive Current

The drive current on the PMIC, RDY, and ON OFF pins is minimal. 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-T 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-T Hardware Manual

  mosaic-T

The centerpiece of the mosaic-T Timing GNSS breakout board, is the mosaic-T 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.

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RTK Not Supported

The mosaic-T is a superb GNSS module designed for highly accurate timing applications. But it does not support RTK. It can not be configured as a RTK Rover or Base. RTCM output is not supported.

mosaic-T module

The mosaic-T module on the mosaic-T Timing GNSS 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
    DGNSS 40cm
    ~1.3'    		 70cm
    ~2.3'
    SBAS 60cm
    ~2'    		 80cm
    ~2.6'
    Standalone 1.2m
    ~4'    		 1.9m
    ~6.2'

Info

The mosaic-T 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-T module.

Supported frequency bands

The frequency bands supported by the mosaic-T 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

RTK Not Supported

The mosaic-T is a superb GNSS module designed for highly accurate timing applications. But it does not support RTK. It can not be configured as a RTK Rover or Base. RTCM output is not supported.

Correction Horizontal Vertical
DGNSS 40cm
~1.3'		 70cm
~2.3'
SBAS 60cm
~2'		 80cm
~2.6'
Standalone 1.2m
~4'		 1.9m
~6.2'

Tip

For the best performance, we highly recommend that users select a compatible L1/L2/L5 (tri-band) GNSS antenna and utilize a low-loss cable.

Peripherals and I/O Pins

The mosaic-T features several peripherals and I/O pins. Some of these are broken out as pins on the mosaic-T Timing GNSS breakout board; whereas, others are broken out to their specific interface (i.e. µSD Carsd slot, USB connector, etc.). Additionally, some of the pin connections are shared with other components or interfaces.

I/O pins

The I/O pins on the mosaic-T Timing GNSS breakout board.

Peripherals

The peripheral interfaces of the mosaic-T Timing GNSS breakout 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
  1. Not available on the mosaic-T Timing GNSS breakout board.

I/O Pins

There are thirty I/O pins on the mosaic-T Timing GNSS breakout board, most of which are connected to other interfaces and components of the board. The tabulated section below, details the aspects of each pin based on their function.

UART I/O pins
The COM pins on the mosaic-T Timing GNSS breakout board.

The mosaic-T has four UARTs that are organized into separate COM ports, three of which are available through PTH pins. The operation for each of these ports can be configured separately.

  • 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.

Info

By default, the COM ports will be configured with the following settings:

  • Baudrate: 115200bps
  • Data Bits: 8
  • Parity: No
  • Stop Bits: 1
  • Flow Control: None
Where is COM3?

COM3 is available through the JST connector, but the pins can also be accessed from the pads on the bottom of the board.

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 mosaic-T Timing GNSS breakout board.

PPS signal I/O pin
The PPS output signal on the mosaic-T Timing GNSS breakout board.

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-T Timing GNSS breakout board. This 3.3V signal output can be access through the PPS pin. The signal is also connected to the PPS LED, to be used as a visual indicator.

Disable LED

There is a jumper attached to the PPS LED. For low power applications, users can cut the jumper to disable the PPS LED.

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

Data logging I/O pins
The data logging pins on the mosaic-T Timing GNSS breakout board.

The data logging functionality of the board can be configured through the software/web interfaces and operated through the use of the LOG button or LOG BTN pin. Data logging activity will be indicated by the LOG LED.

  • LOG BTN - Connected to the LOG button and tied to the same active-high, input of the mosaic-T
  • LOG - Connected to the LOG LED

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)

Operation

The data logging feature can be controlled on the board through either the LOG button or LOG BTN pin.

  • Pressing the button or pin LOW (< 5s) toggles data logging to the SD card on and off.
  • Holding the button or pin LOW 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
Status

The status of the SD card and data stream are indicated on the LOG LED and pin.

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

LED I/O pins
The LED pins on the mosaic-T Timing GNSS breakout board.

The mosaic-T module features two general purpose, output LED pins. These pins have a maximum output current of 10 mA and output impedance of 20Ω. In addition, to these pins, there are other status LEDs connected to other signals on the board.

  • The general purpose LED signals are connected to the RTK and PVT pins; and respectively, the RTK and PVT LEDs.
  • The PPS output signal is connected to the PPS pin and PPS LED.
  • The LOG pin is connected to the LOG LED.

Info

For more details, please refer to the Status LEDs section.

The mosaic-T module features two general purpose, output pins. These pins can drive a maximum current of 10mA.

General purpose I/O pins
The GPx pins on the mosaic-T Timing GNSS breakout board.

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

Event trigger I/O pins
The event pins on the mosaic-T Timing GNSS breakout board.

Example

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

Power management I/O pins
The power managment pins on the mosaic-T Timing GNSS breakout board.

Reset

  • Reset Pin
    Used to reset the mosaic-T module.

Power Mode

Info

For more details, please refer to the Power Modes section.

  • RDY Pin
    The RDY pin indicates the operational mode of the mosaic-T module. The level is high when module is operating, and low when in standby or reset.
  • PMIC Pin
    The PMIC pin is typically connected to a power switch or the control pin for the primary power supply, which is used to transition the module between its Active and Standby states.
  • ON OFF Pin
    When the ONOFF pin is driven LOW (>50ms), the module toggles between its Active and Standby states.

Power supply I/O pins
The ppower supply pins on the mosaic-T Timing GNSS breakout board.

Info

For more details, please refer to the Power section.

  • VBATT Pin
    Always-on power supply, which must remain available when 3V3 is disable, by the PMIC pin
  • VUSB Pin
    The voltage from the USB-C connector, usually 5V
  • VIN Pin
    Alternate input supply voltage for the board
  • 3V3 Pin
    Main power supply input, controlled by the external power switch
  • GND Pin
    The common ground or the 0V reference for the voltage supplies

USB-C Connector

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

USB interface

USB-C connector on the mosaic-T Timing GNSS breakout board.

  1. When the board is initially connected to a computer, the module will initialize as a USB mass storage device.
    • For Windows PCs, the USB driver 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.
  2. Once the USB driver is installed:
    • Two virtual COM ports are emulated, which can be used as standard serial interfaces 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.

SMA Connectors

There are two SMA connectors on the mosaic-T Timing GNSS breakout board.

L1/L2/L5/L

The L1/L2/L5/L SMA connector provides an input for a compatible GNSS antenna. The type of antenna used with the mosaic-T module will affect the overall performance of the GNSS receiver.

GNSS antenna input

The SMA connector to attach a GNSS antenna to the mosaic-T Timing GNSS breakout board.

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.

  • 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 connector already provides active power at 3.3V.

    Danger

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

  • The more frequency bands an antenna supports, often equates to a gain in the performance.

    • Faster acquisition time.
    • Access and support for the L5 GPS band can potentially mitigate multi-path errors.
    • Less susceptible to jamming and spoofing.

Tip

For the best performance, we recommend users choose a compatible L1/L2/L5/L-band 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.

EXT REF

The primary feature of the mosaic-T is that it can be utilized to create a GNSS disciplined oscillator and calibrate an external reference clock to an accuracy of 20ns.

External reference clock input

The JST connector on the mosaic-T Timing GNSS breakout board.

  • The INT/EXT slide switch selects a reference clock source from either:

    • The internal TCXO of the mosaic-T module
    • An external clock signal from the EXT REF SMA connector

    Warning

    If the reference clock switch is set to EXT, users must provide a 10MHz input signal. Otherwise, the mosaic-T module will cease to operate, without a clock signal. Additionally, switching between external and internal frequency reference must occur when the module is powered off, or the module must be reset after switching.

  • The EXT REF SMA connector accepts a 50Ω, 10MHz signal with the following requirements:

    • Preferably a sine wave or a band-limited square wave
    • Power: -14dBm (min); +14dBm (max)
    • Frequency tolerance: +/-2.5ppm
    • Allan variance: better than 1ppb (for τ=1s)
    • Phase noise: better than -90dBc/Hz at an offset of 10Hz

    Tip

    If a CMOS or LVTTL signal is used with long traces from the source, it is recommended to filter them at the source with an RC filter with a pole near 100 MHz.

JST Connector

The mosaic-T Timing GNSS breakout board features a 6-pin JST GH connector, which is polarized and locking. Users can access the COM3 port of the mosaic-T module through the JST connector with our breadboard cable.

JST Connector

The JST connector on the mosaic-T Timing GNSS breakout board.

JST pins

The pin connections of the JST connector on the mosaic-T Timing GNSS breakout board.

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 mosaic-T Timing GNSS 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 record and store data on the board.

SD card slot

The µSD card slot on the mosaic-T Timing GNSS breakout board.

SD Card Specifications

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

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)

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).

Operation

Data logging can be controlled on the board through either the LOG button or LOG BTN pin.

  • Pressing the button or pin LOW (< 5s) toggles data logging to the SD card on and off.
  • Holding the button or pin LOW 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

Status

The status of the SD card and data stream are indicated on the LOG LED and pin.

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

Status LEDs

The status indicator LEDs on the mosaic-T Timing GNSS breakout board.

Log Button

The LOG button allows users easily control the data logging feature and the µSD card, once the data stream has been initially configured for the module.

Buttons

The LOG button on the mosaic-T Timing GNSS breakout board.

Data logging can be controlled on the board through either the LOG button or LOG BTN pin.

  • 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

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)

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).

Status

The status of the SD card and data stream are indicated on the LOG LED and pin.

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!

There are eight 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-T Timing GNSS breakout board.

LED Jumpers

Five of the jumpers 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.
VBATT

This jumper can be cut to disconnect the VBATT pin from the 3.3V output of the AP7361C LDO regulator.

Info

The VBATT pin is the always-on power input for the mosaic-T module, which is necessary for the module to enter Standby mode.

  • By default, the VBATT pin connected to the 3.3V output of the AP7361C LDO regulator. Therefore, the mosaic-T module will shutdown, if power is disconnected from the VUSB and VIN inputs.
  • If cut, an external power source must be connected to the VBATT pin to keep the module powerd in Standby mode.
VOUT

This jumper can be modified to change the output voltage on the JST connector to 3.3V.

Info

By default, the jumper is configured to provide a 5V output when available from the VUSB or VIN power sources.

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