Communicating with onboard Ublox using U-Center

[lewissw (Steve)]

UPDATE: No luck with the DF13, it seems to be buried in RTKLIB code and behind the Intel Edison interface. I really wish I could use U-Center to command the Ublox to do whatever I want it to do. I need all of the raw data (ubx). Not just the three messages that RTKLIB uses.

First of all…awesome product!!! I’m already having a lot of fun exploring the hardware/software.

Any chance the Emlid team will release a script like the one for Navio that would allow two-way communication with the onboard Ublox using U-Center?

(I’m getting a USB UART controller today that may resolve this over the DF13 connection. I will post updates)

[egor.fedorov]

Hi!

U-center supports tcp connection, which probably easier, then connecting via serial. You have two options here:

1. You can set Reach into Rover mode and configure Raw data logs to be a tcp server. Once you save and load, you will be able to connect to Reach with u-center. However, the connection will only work one way, so you won’t be able to configure u-blox via u-center this way.

2. Set Reach into Base mode and make sure it is stopped. This way, the u-blox serial device is not locked. Then, ssh into Reach and run the following command:
   socat /dev/ttyMFD1,b230400,raw,echo=0,unlink-close=0 tcp-l:4000,reuseaddr,fork
   This will make a two-way bridge between u-blox and a TCP port.

[lewissw (Steve)]

Awesome…you saved me so much time! Thank you Egor!

For anyone interested. I’m attaching screen shots of how I used Ublox U-Center, with the techniques described by Egor, to Survey-In my RTK Base receiver.
Link to U-Center (its free from Ublox): u-center

The settings I used were not ideal, only for demonstration purposes. You will want to survey-in over a longer time span at a better location than I did (mine was near buildings because I didn’t have time to go anywhere).

Surveying-In allows you to obtain a very accurate base location in llh to type into the ReachView Base Station configuration.

U-Center has many other features and gives you access to a lot GNSS data “under-the-hood.”

Enjoy!

First, select from the Configure Menu: [CFG], [TMODE2 (Time Mode 2)], then select from the drop-down menu: [1 - Survey-in]; it has a default [minimum observation time = 86400], you can change this to however long you would like, but its not as important at the the [required position accuracy]. As you can see, once you [Send] the command, the Survey-In will only end once BOTH conditions are met. The default position accuracy is 0.001 m; I don’t think this is achievable with this type of receiver, so select something reasonable for your application. Perhaps 40-50 cm.
Once, you send the Survey-In command you can watch its progress on the Configure [TIM], [SVIN (Survey-in)] submenu.

Once the Survey-in completes it will say “Successfully finished”

You will need to go back to the [CFG], [TMODE2 (Time Mode 2)], then select from the drop-down menu: [2 - Fixed Mode]; it will first show the mean position in ECEF, select the check-box [Use Lat/Lon/Alt Position] in order to get the llh format required by ReachView.

Type in the Base latitude, Base longitude, Base height and click Save & Load

Start your rover, following the instructions provided by Emlid. Notice the status says “float”–I got this while indoors with my rover!!! and my base was set-up next to buildings!!! Not recommended for most applications

[Ne0tuX]

Hi egor,
Is there a way to make a two-way bridge while conneced via serial?
I configured the Reach into Base serial mode. U-center receives the NMEA sentences but all configuration messages sent from U-center seem not to be received by the Reach (One way connection).
My aim is to disable some NMEA sentences using UBX-CFG-MSG message.

[egor.fedorov]

Hi!

The NMEA that is being output is not generated by the internal receiver and therefore can not be configured by u-center.

[Ne0tuX]

Thx for the fast reply!

My aim is to disable some NMEA sentences since my microcontroller has its RS232 reception buffer flooded at 10Hz GPS frequency (8 sentences at 5Hz is OK, so the only 4 usefull sentences at 10Hz should be OK).

If the NMEA sentences displayed by U-Center are not from the chip itself and cannot be configured by the mentionned software, do you know any other alternative?

[tatiana.andreeva]

Hi @Ne0tuX,

I’d like to point out that we usually don’t recommend making any changes in the Reach software. Once you change anything, it’s becoming difficult to predict how Reach and ReachView will perform. In this case, we can’t see the whole picture on what’s going on with Reach device and we can’t predict how the things you’re running on Reach may affect its operation.

As an alternative, I can recommend outputting the NMEA data from Reach on any 3rd-party board which then can separate the data and provide you with the required messages only.

[Ne0tuX]

Hi @tatiana.andreeva,

I understand your concern, but right know, no change have been made on my Reach software, thanks. The point of asking on the forum is to find a harmless way to resolve my issue, which is obvisouly critical.

Let me re-explain my problem as directly as possible: my main microcontroller requires a 10 Hz GPS frequency but it can not handle the Reach 10Hz GPS frequency if the 8 NMEA sentences are sent at once (4 would be OK). Unfortunately, I am a pro user so I can not change the microcontroller. The two remaining solutions are:

• to disable some NMEA sentences via software means;
• to find another more configurable GPS for this project.

Besides, I hope that the Reach software is robust enough so that disabling a few NMEA sentences will not result in any behavior change other than reducing the load and that we still can “predict how Reach and ReachView will perform”.

[dmitriy.ershov]

Hi,

In the current version of ReachView there’s no straightforward way to implement the selection of NMEA messages neither via UI, nor via console. In the future, we plan to have this feature, but there’s no ETA for now.