DIY RTK BASE-NTRIP Caster CORS Server with ESP32 and Free DDNS provider - F9P PX1122R

It seems to me that no one uses the PX1122R as a base and Rover.
“satellite Galileo drift” on BS RTK affects the fix RTK for the rover?

1 Like

@fazm. First I must admit I was wrong about the settings of a skytraq rover, it seems to be set from factory. Although I found a place in gnss viewer where you can disable qzss (maybe to get higher Hz nmea output)
But it seems to be difficult to keep a fix, but it does not explain why you are not able to change base settings without going to only float.
Perhaps try msm7 as torriem does.
In following link you see others having problems with skytraq.

1 Like

There ARE settings for rover:
http://www.navsparkforum.com.tw/viewtopic.php?f=39&t=1867&p=5792&hilit=rover+constellation#p5792

http://www.navsparkforum.com.tw/search.php?keywords=rover+constellation&terms=all&author=&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search

User guide for GNSS Viewer:Documents — NavSpark

1 Like

Thanks Larsvest, I studied the information on the links, I did not find a solution to my problem.

I enabled “Survey mode” on the RTK base yesterday and set the observation time to 36000 sec. It has been more than 12 hours, the measurement has still not stopped.
If I set the measurement duration to 60 seconds, the measurement stops.
The user manual shows the time in seconds.

RTK base mode
Saved Opt. Function: Survey Mode
Saved Survey Length:36000
Standard Deviation:30
Run-time Opt. Function: Survey Mode
Run-time Survey Length:4294860533

1 Like

If it does not stop surveying in, and 12 hours is gone, then you did not get within 30 cm precision. Your picture also shows that you got around 80 cm in that time. I just used 300 sec and 30 cm. It works as base for f9p. The long time surveying should be send in for calculating precision point

1 Like

I think I found the reason, it seems that my used antenna only has the L1 band or the L2 is broken. My used antenna is not labeled.
To give you an example:
In the RTCM 1074 of my BS RTK “Skytraq”, there are only messages:
MT1074 ToW 128366.0000 Signal L1_C/A

In RTCM 1074 commercial BS RTK “TRIMBLE BD970”, the messages:
MT1074 ToW 128585.0000 Signal L1_C/A
MT1074 ToW 128585.0000 Signal L2_Z-Track
MT1074 ToW 128585.0000 Signal L2C(M+L)
MT1074 ToW 128585.0000 Signal L5_I+Q

I need to check my guess

1 Like


Please check the antenna again.
Andrew Hsu from SKYTRAQ team thinks the L2 deficiency is the problem.

Thank you esprtk for your prompt reply.
Now I have replaced the antenna with 2J7C01MC2F L1L2.
And the RTCM messages have the range L1, L2, G1, G2.

MT1074 ToW 183078.0000 Signal L1_C/A
MT1074 ToW 183078.0000 Signal L2C(L)

MT1084 ToW 193859.0000 Signal G1_C/A
MT1084 ToW 193859.0000 Signal G2_C/A

but I have not tested it yet, I will publish the result soon.

Hi,
After my test, when Base disable SBAS.QZSS or rejoin SBAS, QZSS, it will reboot, the rover drops from rtk
fix to normal gnss fix or float, then the rover needs to take some time to re-resolve ambiguity, in my case
around 60 seconds to regain RTK fix. It can remain RTK fix after regain RTK fix.
Below, picture, the left is Rover, the right is Base, Base TX wired to Rover RX.

Your receptions of L2 on the rover receiver is not good, no L2 actually for RTK.
Did you do a cold start on the Rover after the base disable SBAS and QZSS at runtime? Was the rover able
to get RTK fix? though, in my test, I did not do a cold start.
Best regards,
Andrew

These are picture posts, so you can find them in a search.
You can move it to your own message.

1 Like

I copy and paste your comment to this room to ask Skytraq team :
https://www.navsparkforum.com.tw/viewtopic.php?f=39&t=1917

We are still waiting for your result.

So, I got the results (PX1122R ).
My assumptions about the antenna were confirmed.
The problem was the antenna, the antenna was working in the L1 band.
In the user guide “GNSS-Viewer-User-Guide.rev0.2.pdf” there is no information about controlling the L1/L2 or L1 band.
Set GNSS to RTK base mode “RTK” - “Configure RTK Mode And Operational Function”.

My antenna is super strange!!!
Set GNSS to RTK base mode “RTK” - “Configure RTK Mode And Operational Function”, only L1.

Set GNSS to RTK rover mode “RTK” - “Configure RTK Mode And Operational Function”, L1 and L2.

1 Like

My recommendations configuring GNSS PX1122R RTK base mode.
First, execute “Binary - Set Factory Default”.
Identify constellations with many satellites.
Don’t forget to save your changes in flash “Update to SRAM+FLASH”

Satellites many

I selected GPS, GLONASS, BEIDOU.
Then “Venus8”. - “Configure GNSS Constellation Type”

Constellation Type

Then select the RTCM messages according to the selected constellations “RAW” - “Configure RTCM Measurement Data Out”.

Next, switch GNSS to RTK mode “RTK” - “Configure RTK Mode And Operational Function”.

Then do cold start.

Cold Start

1 Like

My recommendations configuring GNSS PX1122R RTK rover mode.
First, execute “Binary - Set Factory Default”.
Don’t forget to save your changes in flash “Update to SRAM+FLASH”

Select output interval of navigation message “Binary” – “Query and Configure NMEA Message Interval”, in seconds.

Configure Position Update Rate, “Binary” – “Configure Position Update Rate”

Update Rate position

Configure GNSS Constellation Type, Selected GPS, GLONASS, BEIDOU “Venus8”. - “Configure GNSS Constellation Type”

Constellation Type

Next, switch GNSS to RTK rover mode “RTK” - “Configure RTK Mode And Operational Function”.

Then do cold start.

Cold Start

My region is on the border of Europe-Asia, the visibility of the satellites is limited by the Ural Mountains, it was also snowing during testing, so I turned on all the constellations for a stable RTK fix.

1 Like

Very good work, and now we have a manual for setting up skytraq base and rover. But I have a question. Is the interval in seconds or Hz? Rover output is preferred to be 10 Hz for AOG.

1 Like

Interval in Hz, as in the image.
High frequency “Position Update Rate” requires more constellations to fix RTK.
A setting of 1 Hz is suitable for static measurements or very slow driving with fewer constellations.

1 Like

I don’t see the hz mentioned after gga interval, which is set to 1

1 Like

Yes, of course it’s in seconds.

1 Like

Looks like it’s configured similarly to the F9P where the base rate is set to 10 hz and the the interval of 1 means emit GGA every time (10 hz), whereas if you set it to some other number like 5, it would mean emit GGA ever 5 ticks or 2 hz.

1 Like

Let us hope so🙂
But if AOG don’t want to steer properly, this paper could have a explanation:
On page 15 it say seconds.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.macrogroup.ru/docs/801&ved=2ahUKEwi39o3F7vD1AhUvSfEDHSYQC6kQFnoECAMQAQ&usg=AOvVaw0JPa-APGgCBvUs0ywgZ08j

1 Like

I think what it means is the message rate is equal to the position update rate (10 Hz) times the interval (1 second). This means 10 times a second. I’m basing this on the fact it is 0-255. And if you set the interval to 2 seconds, that would be the equivalent of 5 Hz. The reason for this is because sometimes you might want different messages to be at completely different rates, although they all have to be based on that 10 Hz base rate that was set. But I agree it could be clearer. And I could still be wrong. I haven’t actually measured the output frequency yet.

1 Like