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Bug #269

input/output error

Added by Youssef Aboudorra about 2 months ago. Updated about 1 month ago.

Status:
Closed
Priority:
High

Description

I am trying to use the following GPS HW using gps-genom3

SIRIUS RTK GNSS ROVER (F9P)
SIRIUS RTK GNSS BASE (F9P)

I created two instance of the components on the same PC, one for the base and one for the rover. I was able to connect to both of them, and connect them together for the rtk data (localhost ip, udp port of choice ). However I always 'Input/output error' whenever I call

unfix
fix 
fix_here 
send_rtcm
#1

Updated by Anthony Mallet about 2 months ago

The ublox driver does not yet support base-station mode, but this
could be added for ublox High Precision GNSS products.

The hardware that support base-station mode are currently either
Tersus-BX3xx or Novatel OEM6 (or later) products.

#3

Updated by Anthony Mallet about 1 month ago

  • Status changed from New to Feedback
#4

Updated by Youssef Aboudorra about 1 month ago

Hello, sorry for the late response but I wasn't notified when you updated the repository, only when you changed the status of the issue yesterday.
By subscribing to the mailing list will I be notified later about any updates in the repository ?

Regarding the issue, I tested it and the problem seems to be solved:
- I was able to set the HW in base mode using fix_here() and send the RCTM messages.
- the mobile station connects to the base station and receives the messages
- fix type is ::gps::fix_fixed for the base station
- fix type is ::gps::fix_float for the mobile station

Is there any guide on how to get the max accuracy fix for the mobile station (procedure, which rctm messages to enable, interval,offset )?
I am currently using these RCTM messages: (1005, 1077, 1087,1127)

Thanks a lot for your support Anthony :)

#5

Updated by Anthony Mallet about 1 month ago

  • Status changed from Feedback to Closed

Good!

Yes, gathers commits messages related to the
robot platform at LAAS, and it has been notified of got those
commits. I thought redmine would notify when adding a related commit
to an issue, but apparently it does not.

You should aim at gps::fix_rtk rather than fix_rtk_float for the max
precision. There is no definite trick to reach this, it is mostly a
matter of having a good satellite visibility, clear sky, no
surrounding buildings etc. The ublox manual has a few hints, check it:
https://www.u-blox.com/en/docs/UBX-18010802 (section 3.1.5). You
should also set the base station position to the best possible
precision, for instance by averaging the position for 1 day or more.

RTCM 1005 can be broadcasted at a very low frequency, like 30s
period. MSM7 messages may be broadcasted at like 2s period. Note that
for glonass (1087), you also need 1230 (as stated in the ublox
manual). It might also be worth checking the 4072.0 proprietary
messages (with e.g. Ucenter) to see if they provide improvements or
not.

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