GNSS device bring up query

GPS/GNSS
1

Hi,

The GNSS device accuracy looks good in RTK mode. So, we want to try out few devices. Before that, we had a few doubts regarding the interfaces required to get the location data from the devices using RTK. This is generic question for all the devices like RTK express, RTK mosaic and RTK reference station… etc.
Requirement:

  1. We are planning to use any one of the above mentioned devices as both rover and base. Example: we want to configure two RTK mosaic-x5 devices, one as base and another as rover.
  2. We want to interface UHF radio from different make which is having a 2W Tx power capability
  3. We want to get the data over a serial interface in NMEA format from the rover most likely over USB.

Can you please summarize what goes where?
Can we select the base device while configuring the rover to get the correction data?
Any converters we may need?
Please explain this by taking RTK mosaic-x5 as an example.

Thank you.

2
  1. You’d just set them as such in the UI Web Interface - Hookup Guide - SparkFun mosaic-X5 GNSS Breakout Board
  2. Depending on the radios’ voltage level, you’ll likely need to use a logic level converter to interface with a UHF radio (other folks on here have done so successfully using 12v radios)
  3. Sure - you can also use the pins on the side of the board instead so you can leave the usb port free for other stuff (settings, etc)

They have a lot of great videos that show you how to interface with the device :slight_smile:

3

RTK reference station hook-up guide has the following descriptions for respective IO pins. In this, it is mentioned that TXD and RXD pins are not used in the current version of RTK firmware.
What does it mean?
Does it mean com1 is not usable and only com2 port will be usable?
If so, how to connect UHF radio for the reception of correction and log location data to the system simultaneously if only a single port is enabled?

Please provide clarity on it.

Following are lines from hook up guide:
TXD : ESP32 pin 17 Serial1 (UART) transmit: 3.3V OUTPUT
The current version of the RTK firmware does not use this pin
RXD : ESP32 pin 16 Serial1 (UART) receive: 3.3V INPUT
The current version of the RTK firmware does not use this pin
TX2 : u-blox ZED-F9P UART2 transmit: 3.3V OUTPUT
You can connect this pin to a radio module to provide correction data to other Rovers
RX2 : u-blox ZED-F9P UART2 receive: 3.3V INPUT
You can connect this pin to a radio module to use correction data provided by another Base

Are SparkFun RTK mosaic-X5 and SparkFun RTK Express Kit (GPS-18380) equipped with NTRIP client and server?

This is how we are planning to use the device in both rover and base mode. Suggest for any changes if required.

Sparkfun Mosaic X-5
Sparkfun Mosaic X-5960×720 55.9 KB

4

Apologies, I didn’t catch that beforehand…in this case it might be better to grab the board version SparkFun Triband GNSS RTK Breakout - mosaic-X5 - GPS-23088 - SparkFun Electronics then

Here is the rest of the kit

5

Hi @TS-Russell ,

Thanks for the suggestion. Our team already brought the RTK Mosaic x-5. I would really appreciate it if you could give us clarity on whether we can use the complete product (RTK Mosaic x-5) instead of the breakout board as shown in the diagram and also the statements provided in the hook-up guide RTK reference station, as a few UART pins are unused in the latest firmware.

Are SparkFun RTK mosaic-X5 and SparkFun RTK Express Kit (GPS-18380) equipped with NTRIP client and server?

6

Hi @shabaz ,

For the complete SparkFun RTK mosaic-X5 product:

You can connect your computer to the CONFIG MOSAIC USB port. You can then connect to its internal web server on 192.168.3.1 using Ethernet-over-USB. Or you can also connect to additional COM ports which appear when USB is connected. You can use RxTools to communicate on these COM ports. Or you can enable NMEA on one of those ports and view the data in a serial console / terminal emulator.

To connect a radio to this product, you will need to use these pins:

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You then need to configure the X5 so it outputs the messages you want to transmit (or receive) on COM1.

These pins are connected to the ESP32 only:

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They are not used by the firmware. You can use them if you write your own code for the ESP32.

For the SparkFun RTK Reference Station:

These pins are connected to the ESP32 only:

image
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They are not used by our RTK Firmware. You can use them if you write your own code for the ESP32.

These pins are connected to the ZED-F9P UART2:

image
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You can use them to connect a radio to the ZED-F9P. You can configure which NMEA or RTCM messages to output through the RTK Firmware. Any RTCM data received on the RX2 pin will be used by the ZED GNSS.

Best wishes,
Paul

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7

To answer your question about NTRIP:

The mosaic-X5 can connect to an NTRIP Server as a Client. It can also act as a local NTRIP Server and local Clients can connect to it. You need to configure this through the internal web page.

The SparkFun RTK Express runs our RTK Firmware. It can connect to an NTRIP Server as a Client. It can not act as an NTRIP Server itself. The firmware does not support that.

Best wishes,
Paul

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8

For NTRIP Casting:

The mosaic-X5 can act as a Base and send corrections to an NTRIP Caster (RTK2go etc.). It can also act as a Rover and use corrections from an NTRIP Caster.

The RTK Express can do the same thing. It can be configured as a Base and send corrections to a Caster. It can also be configured as a Rover and use corrections from a Caster.

Only the mosaic-X5 can act as a local NTRIP Server, and have local NTRIP clients connect directly to it.

I hope this helps!
Paul

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