Quickstart Guide

The TX2 is a compact all-band GNSS RTK rover designed to optimize your on-site workflow. Simply open your preferred GIS app on any mobile device, pair the TX2 as a BLE device, and access NTRIP corrections using the internet/cellular connection. With its MFi certification, users can now pair the TX2 with Apple's iOS devices! This entire kit ships in a hard-sided case, including additional accessories, and a sticker.

Parts List

The SparkPNT TX2 comes shipped inside a hard-sided carrying case with a few accessories to users get started. Below, is an overview of all the parts included with your purchase:

All the parts included in the carrying case.

1. Carrying Case
2. SparkPNT TX2
3. USB-C Cable
4. USB-C Charger (65W)
5. Thread Adapter (1/4" to 5/8")

Device Overview

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Tilt compensation is not supported by this device.

Power

To power the device on or off, hold the power button down for more than 3 seconds. When the device powers on, it will beep once; whereas, the device will beep three times when it powers down.

Power button on the front of the device.

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The center of the power button also serves at the NRP (north reference point) for the device.

Battery

The TX2 features a 49Whr battery and supports PD charging, up to 10W.

Users can access the USB-C port, under the rubber cover, on the back of the device.

• Battery Charging - The TX2 supports PD charging up to 10W; this allows a fully discharged TX2 to be charged to 100% in a few hours. Users can access the USB-C port, under the rubber cover on the back of the device.
  tip

  Don't forget to fully close the rubber cover. The enclosure's IP67 ingress rating (waterproof to 1 meter, for up to 30 minutes), is only valid when the USB cover is closed.

• Battery Capacity - The TX2 includes a 7.2V 6.8Ahr (48.96Whr) battery. This should allow the device to run continuously for more than 50 hours, even in the worst-case conditions.

Connectivity

In order to get corrections or configure the device, users should pair the device with their phone. Double-tap the Power button (press twice, within 1 second) to connect to your device.

BLE

To provide RTK corrections from an NTRIP caster (or server), view the device's position in real-time, and manage datapoints, it is best to utilize a 3rd party app on a mobile device. Users can then, pair the SparkPNT TX2 to their mobile device with a BLE connection.

For a Bluetooth connection, follow these steps:

1. Power the device on.
   • Hold the Power button for more than 3 seconds. It will beep once, indicating it has turned on.
2. Once the device has powered up; double-tap the Power button (press twice, within 1 second).
   • The device will beep twice indicating it is waiting for incoming connections.
3. On your mobile device, connect to BLE device named SparkPNT TX2.

   

   Pairing from an Android device.

   

   Pairing from an iOS device.

4. Once pair, you be able to access the device in your favorite GIS app.

WiFi

To change the configuration settings of the SparkPNT TX2, it is easiest to connect to the device's WiFi access point and pull-up the configuration webpage. Once connected, users can access the configuration webpage from a browser using the https://rtk.local URL address.

To get into browser configuration, follow these steps:

1. Power the device on.
   • Hold the Power button for more than 3 seconds. It will beep once, indicating it has turned on.
2. Once the device has powered up; double-tap the Power button (press twice, within 1 second).
   • The device will beep twice indicating it is waiting for incoming connections.
3. On your mobile device, connect to WiFi network named RTK Config. Upon connecting, your phone may warn you that the WiFi network is not connected to the internet. This is normal; stay connected and open a browser.

   

   Connecting from an Android device.

   

   Connecting from an iOS device.

   warning

   If you have problems, try disabling mobile/cellular data on your mobile device. The device or browser might be using the cellular connection for its internet access; however, we want to disable this setting to ensure that your mobile device remains on the WiFi access point for the browser.

4. Once the browser is opened, you should be automatically re-directed to the configuration webpage. If not, open a browser (Chrome is preferred) and type http://rtk.local into the address bar.
   
   

   https://rtk.local/

   http://rtk.local/

   

   Browser with rtk.local webpage.

Status Indicators

There are three LED status indicators on the TX2.

The LED status indicators on the SparkPNT TX2.

• The GNSS icon () indicates the GNSS solution status.
  • A yellow LED will blink once per second when a GNSS fix is achieved.
  • A green LED will illuminate solid when RTK Fix is achieved.
• The Connection icon () indicates the WiFi or BLE connection status.
  • The LED blinks once per second while waiting for a connection.
  • The LED will turn solid, once it is connected to a phone, laptop, WiFi network, etc.
• There is a small battery LED next to the cover of the USB port, on the back of the device.
  • The LED is green when external power is supplied.
  • When the device is on:
    • The LED will be solid red indicating more than 50% battery capacity remains.
    • The LED will blink red once per second, if less than 50% of the battery capacity remains.

Initial Setup

Users simply need to attach their TX2 to a surveying post or mount point using the 5/8"-11 TPI threaded insert on the bottom of the TX2. This kit also includes a 1/4" adapter for additional mounting options.

The 5/8"-11 TPI threaded insert on the base of the SparkPNT TX2.

Orientation and Alignment

For the most accurate positioning, users should align their device as vertically straight as possible. Additionally, the user interface's power button (front of the device) should be facing north as defined by the device's north reference point.

The antenna reference point and north reference point of the SparkFun TX2.

When marking positions, users can also provide the pole height and distance between the ARP and APC in the RTK Everywhere firmware. This will allow users to accurately mark their positions based on the bottom of the surveying pole.

Placement and Surroundings

This section provides general placement considerations for precision GNSS surveying. Below, are some useful examples of ideal locations for surveying.

• Ideal locations
  • Open fields
  • Hilltops
• Poor locations
  • Canyons and valleys
  • Cities or dense urban areas
  • Dense foilage

Obstructions and Multipath

For precision GNSS surveying, the receiver works best with a wide-open, unobstructed view of the sky.

A wide-open, unobstructed view of the sky offers increased accuracy and precision.

Obstructions can create multiple paths for signals. This introduces timing errors into the solutions provided by the GNSS receiver reducing its precision and accuracy.

The increased signal paths, introduce timing errors into the solutions provided by the GNSS receiver.

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By default, the TX2 ignores any signals from satellites positioned below, 15° above its horizon (see image). This mitigates any multi-path errors from any obstacles on the horizon; such as buildings, trees, cars, etc.

The TX2 ignores any signals from the horizon (<15°) and only accepts signals from above (green).

Obstructions can also reduce the performance of the GNSS receiver and the precision of its solutions.

Obstructions reduce the distribution and number of satellites used in solutions.

Dilution of Precision

The geometric arrangement of satellites, significantly influences the precision of GNSS solutions. A well-distributed arrangement of satellites allows for more accurate positioning by minimizing errors related to signal distortion and multipath effects. When satellites are positioned at wide angles relative to each other, the geometric dilution of precision improves, enhancing precision of the positioning solutions. Conversely, when satellites cluster closely together in the sky, it can lead to degradation in the geometric dilution of precision and less reliable positioning solutions. Therefore, optimal satellite geometry is crucial for achieving high-precision GNSS solutions.

A wide-open, unobstructed view of the sky offers increased accuracy and precision.

RF Interference Sources

Nearby electronics can interfere with the reception of the GNSS signals. It is recommended that users limit the use of wireless electronics that produce RF noise. Especially those that operate near the frequencies of GNSS signal bands. This includes environments with high amounts of EMI, such as around TV broadcast stations or vehicles, radio masts, transmission towers, and overhead power lines.

GNSS frequency bands (Source: Novatel)

SWMaps App

Android

1. Download SW Maps. This may not be the GIS software you intend to do your data collection, but SW Maps is free and makes sure everything is working correctly out of the box.

   

   Download SW Maps for Android

2. Attach the TX2 to a 5/8" 11-TPI standard surveying pole or to a monopole using the included thread adapter.
3. Turn on the TX2 device by pressing the Power button for 3 to 4 seconds until a beep is heard and the two front LEDs illuminate.
4. From your cell phone, open Bluetooth settings and pair it with a new device. You will see a list of available Bluetooth devices. Select the SparkPNT TX2-3AF1; where, 3AF1 is the last four digits of the device's MAC address and will vary depending on the device.
5. Once paired, open SW Maps. Select New Project and give your project a name like RTK Project.
6. Press the SW Maps icon in the top left corner of the home screen and select Bluetooth GNSS. You should see the SparkPNT TX2-3AF1 in the list. Select it. Confirm that the Instrument Model is SparkFun RTK, then press the Connect button in the bottom right corner. SW Maps will show a warning that the instrument height is 0m. That's ok.

   

   Connecting to the TX2

7. Once connected, have a look at the Connection icon () on the device. You should see the LED turn solid. You're connected!
8. Now move the TX2 outside with a clear view of the sky. GNSS doesn't work indoors or near windows. Press the SW Maps icon in the top left corner of the home screen and select GNSS Status. Within about 30 seconds you should see 10 or more satellites in view (SIV).
   • The higher the SIV (number of satellites in view), the better. We regularly see 30 or more satellites, at SparkPNT. The horizontal positional accuracy (HPA) will start at around 10 meters and begin to decrease. The lower the HPA, the more accurate your position. This accuracy is around 2m in normal mode.

   

   Number of satellites in view, reported by the TX2.

iOS

1. Download SW Maps for iOS. This may not be the GIS software you intend to do your data collection, but SW Maps is free and makes sure everything is working correctly out of the box.

   

   Download SW Maps for iOS

2. Attach the TX2 to a 5/8" 11-TPI standard surveying pole or to a monopole using the included thread adapter.
3. Turn on the TX2 device by pressing the Power button for 3 to 4 seconds until a beep is heard and the two front LEDs illuminate.
4. Open SW Maps. Select New Project and give your project a name like RTK Project.
5. Press the SW Maps icon in the top left corner of the home screen and select Bluetooth GNSS. You should see the SparkPNT TX2-3AF1 in the list. Select it. Confirm that the Instrument Model is SparkFun RTK, then press the Connect button in the bottom right corner. SW Maps will show a warning that the instrument height is 0m. That's ok.
6. Once connected, have a look at the Connection icon () on the device. You should see the LED turn solid. You're connected!
7. Now move the TX2 outside with a clear view of the sky. GNSS doesn't work indoors or near windows. Press the SW Maps icon in the top left corner of the home screen and select GNSS Status. Within about 30 seconds you should see 10 or more satellites in view (SIV).
   • The higher the SIV (number of satellites in view), the better. We regularly see 30 or more satellites, at SparkPNT. The horizontal positional accuracy (HPA) will start at around 10 meters and begin to decrease. The lower the HPA, the more accurate your position. This accuracy is around 2m in normal mode.

   

   Number of satellites in view, reported by the TX2.