SimpleRTK2B + Heading

Q&A forumCategory: QuestionsSimpleRTK2B + Heading
tksystems asked 3 months ago

Simple question, I think…
I am wanting to update my SimpleRTK2B + Heading firmware (awesome little unit!), and then reup the configuration file.
Do I have to complete this for each individual ublox chip on the board?  OR when I update 1, they both update / when I put in the configuration files provided on the site, do they both receive the configuration files?  Do they get the same firmware / same configuration files?
Thank you in advanced!

3 Answers
clive1 answered 3 months ago

If your system is composed of two ZED-F9P you will need to update the firmware on both individually. As I recall the HPG 1.12 is the most current, though new firmware should be out shortly.
If the heading unit has a ZED-F9H, this will need its own specific HDG firmware, but I don’t think newer firmware has been released for them, and it is not compatible with the HPG firmware.

tksystems answered 3 months ago

I am working with two ZED-F9P that came with the “SimpleRTK2B + Heading” kit.
Just so I follow correctly:

  1. Do I update one ZED-F9P with one usb and the other ZED-F9P with the other usb?
  2. Do I put the same configuration file on both ZED-F9Ps or do they need separate config files to work as a rover with heading?

I appreciate the help! 

clive1 replied 3 months ago

They perform different functions, they need different settings. You can save the configuration from the device in uCenter. It may not need changing. uCenter will complain if there is a firmware version difference, but this is usually the only thing in the file that differs.

Firmware can be updated a couple of ways, easiest perhaps is USB on the main unit, and USB via Dongle (UART1) on the lite unit.

tksystems answered 3 months ago

I have been looking at the settings for the “SimpleRTK2B + Heading”:  I also have the configurations from the GITHUB now.
Filename: “srtk2b+heading_rover_F9P_FW_HPG112.txt”
Starting from a default ZED-F9P configuration:

  • UART1 and UART2 increased to 115kbps
  • Disable NMEA messages in all interfaces, to avoid buffer overflow
  • Enabled on both UART1 and USB:

These boards are both plugged in together and will stay together on the rover (I think this is known, but just want to make sure).
I am unsure which file or group of settings should go on the main board ZED-F9P and which settings should go on the ZED-F9P on the “lite” plug in board.  There must be a concept I am missing.
Do I set one as the Rover and one as the base even though they will both be on the robot receiving NTRIP moving around?  If so, which one is the rover and which is the base? Or does it matter?  I apologize for all the questions, but I have quite confused myself!

clive1 replied 3 months ago

The top side lite board, plugs into the radio, this is the primary rover receiver and act as the “moving base” for the lower board, which is the secondary rover receiver, that provides it’s relative position with respect to the primary.
While the lower/secondary can provide a position, this is twice removed from the fixed base station, a better fix can be had from the upper/primary.

The Fixed Base sends RTCM3 messages/observations to the upper/primary, it computes it’s RTK solution. In Moving Base mode it generates a new set of RTCM3 messages/observations from it’s antenna perspective and feeds the to the lower/secondary unit.

tksystems replied 3 months ago

clive1, Aha! Light Bulb!

I will work ahead with this new understanding.

Thank you much

Simon Bolten replied 3 weeks ago

I still do not completely understand it.

I have the following setup :
– Program on the PC which needs to get a precise Position and Heading
– I have a NTRIP Service which needs to have a position message
– RTK2B Lite on Top of RTK2B

I do the following:
– Upload srtk2b+heading_lite_movingbase_FW_HPG112.txt to the RTK2B Lite
– Upload srtk2b+heading_rover_F9P_FW_HPG112 to RTK2B

As far as I understood it is not possible to get the Position and Heading from only one board and in the same time supply NTRIP RTCM data to the same board. Is this true?

It would be best to connect one USB to the RTK2B Lite, send the RTCM Data of the NTRIP service through this port and read back the NAV-PVT from this board for the Position.
From the RTK2B I only get a precise relative Distance and Heading in relation to the RTK2B Lite board. So I need a second USB connection to the RTK2B and read the NAV_RELPOSNED for Position and Heading.

clive1 replied 3 weeks ago

You can get position and orientation/heading from the unit at the end of the chain, but the position is likely to be less accurate, and more fragile.

Base –RTCM3–> Moving Base –RTCM3–> Rover

If the Rover is an F9P you can get both LLH and NED data from it. (5-8 Hz Max)
If the Rover is an F9H you can get only NED data from it. (10 Hz Max)
For my work I want to know the RTK location of the Moving Base, and place that antenna above the notional center or turning point of the vehicle.
The antenna separation from Moving Base to Rover should be >1 metre. Provided the vehicle doesn’t deform (wings) that should be a constant baseline length, it can be uses as a sanity check.

The Rover should be told where the Moving Base is, passed in the 4072.0 message, I don’t think Rover can report this, but would have been helpful if the firmware could have done that. I think there is a debug/diagnostic message to forward an encapsulated RTCM3 packet.