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SimpleRTK2B Base Configuration For Fix and send always the right gps data, Serial ID, Bind

Q&A forumCategory: QuestionsSimpleRTK2B Base Configuration For Fix and send always the right gps data, Serial ID, Bind
vcorp asked 4 weeks ago
Hi everyone.
After the various tests carried out with the prototype made using arduino mega, I translated all the c++ code into Delphi (Delphi 10.4).
Everything works quite well (I’m talking about the project I’m working on to make an agricultural vehicle autonomous in driving).
As mentioned, everything is working very well, it would be time to switch to using the agricultural vehicle in large spaces (for example a vineyard).
Currently on the agricultural vehicle I have mounted a SimpleRTK2B kit
which I use for navigation and to get the compass (HEAD rear antenna towards the ROVER front one).
While on the ground I have a third SimpleRTK2B that does the RTK correction for me (RTK BASE).
As you all know, if the RTK base is switched off and then switched on again, the GPS coordinates taken previously are no longer valid, unless you perform a calculation based on the fix point detected before starting to memorize a route.
In fact now we proceed in this way:
Before storing a route, we position the ROVER GPS antenna in a fixed point, save those coordinates and use them to shift the data when the rtk base is turned on again.
This procedure while working perfectly is very limiting.
If I understand correctly there is the possibility of teaching the RTK base to always send the right coordinates even after it is turned off and on again.
Question 1:
Could you tell me how to do it, or where to find a guide explaining how to do it? because it would really be a turning point for me.
Question 2:
I understand that each SimpleRTK2B card has a unique code
which can be read via u-center at voice -> UBX-SEC-UNIQID.
Can anyone tell me how to read it from the serial?
It would be really useful to understand who the rear antenna is bcz
it often happens that the com ports are reversed and the agricultural vehicle
it works bad…
Question 3:
Could you also tell me how to make sure that the RTK base sends data only to the SimpleRTK2B kit installed on the 001 agricultural vehicle and not also on the others?
Thanks sorry for the long post, but for convenience. I preferred to open only one.
replied 4 weeks ago

The Query form of UBX-SEC-UNIQID is B5 62 27 03 00 00 2A A5
The Response form is described in the Interface Specifications, basically provides a 5-byte Unique Number.
The Base is a broadcast, should be viable for any Rover(s) in range. You can change the RTCM STATION ID within the Base, and on the radio you can perhaps pick a CHANNEL, NETWORK ID or other settings to narrow-cast it to a specific group or singular radio receiver. I’d imagine that’s documented in the Radio’s Manual. The Rover also has RTCM STATION ID filter settings.
When moving an RTK base, one typically provides a hard point point on a fence post or pole, with a 5/8″ 11 thread rod, so the GNSS antenna can be accurately/repeatedly installed in the SAME spot. You then have a list of existing surveyed points, and pick the one to push in via UBX-CFG-TMODE3 as the current static location, based on a simple proximity test of current GNSS position report vs the list content, or pick the position by name manually.

replied 4 weeks ago

Thanks clive1, i’ll try to figure out your explanation.

replied 4 weeks ago

Not sure I see this as overtly complicated..


Repeatability will be as good as your antenna mounting and ability to return to the same spot, and having a record of what coordinates you used the first time you surveyed the location. Trick is to have logged information, and retain context.

SURVEY-IN is not usable unless you’re averaging positions in RTK FIXED mode using data from a reference source. You should be able to pull data via UBX-CFG-TMODE3, and see in UBX-NAV-SVIN

3 Answers
clive1 answered 4 weeks ago
Static position information can be set via UBX-CFG-TMODE3 (or keys)
RTCM station in/out keys, CFG-RTCM-DF003_OUT, CFG-RTCM-DF003_IN, CFG-RTCM-DF003_IN_FILTER, see Interface Description docs
Low cost hard antenna mount used in sub-divisions under development.. Couple of dollars from hardware store.

vcorp answered 3 weeks ago
Hi everyone I’m playing with u-center to understand how and where to read the identifier of each RTK2B.
However, how to locate the binary string escapes me: “The Query form of UBX-SEC-UNIQID is B5 62 27 03 00 00 2A A5”. Because if I open the binary console I don’t see it (even filtering).
Any suggestions?
replied 3 weeks ago

It’s the QUERY/POLLED form (ie a zero length payload version of the message), so when you open the UBX-SEC-UNIQID tree node in Message View, it sends the query to the receiver, and the receiver sends back a response.
??:??:?? 0000 B5 62 27 03 00 00 2A A5 µb’…*¥.

??:??:?? 0000 B5 62 27 03 09 00 01 00 00 00 7F 4D 92 D3 1A 7F µb’……..M.Ó..
0010 B0

replied 3 weeks ago

Thats ok, but how can i query it outside u-center-

replied 3 weeks ago

Sorry, I haven’t programmed in PASCAL in the best part of three decades. So I’ll use C for illustration.

You’d open a file stream to the COM or TTY, and write the data as bytes.

uint8_t query_ubx_sec_uniqid[] = { 0xB5,0x62,0x27,0x03,0x00,0x00,0x2A,0xA5 };
fwrite(query_ubx_sec_uniqid, sizeof(query_ubx_sec_uniqid), 1, ftty);

In Win32 API parlance, probably CreateFile, WriteFile, CloseHandle

replied 3 weeks ago

i know c, c++, pascal, assembly, php and so on. Your example will be good!

replied 2 weeks ago

Good finally i can know if the rover GPS is on the right com port.

vcorp answered 2 weeks ago
Returning to the question of making sure that the 001 agricultural vehicle (with two rtk2b on board) receives the signal only from the RTK2B xxx base, should the setting be done with u-center or should the xbee LR be programmed?
replied 2 weeks ago

One would need to make some sort of judgement based on the radio documentation.

Personally, I’d probably choose to configure the receiver’s RTCM3 inward filter via my user facing application and its user interface, so as to make it easier to use in the field, and not require running uCenter.

replied 1 week ago

Surely the next step will be that.
In the meantime, I would need to figure out how to do this via u-center if anyone knows how.

replied 1 week ago

Perhaps look at docs for UBX-CFG-VALSET, with keys CFG-RTCM-***
uCenter View Series 9 Advanced Configuration

replied 1 week ago

Found it thanks. Now it’s time to learn this things too!!!