How to NMEA output from Simple RTK2B

Q&A forumCategory: QuestionsHow to NMEA output from Simple RTK2B
kevinemslie asked 3 weeks ago
Hello, 
I have seen a similar question asked on here before but basically i need NMEA messages out to position data to an agricultural GPS display. 
The display has a DB9 port and uses RS232 protocol. 
Is it correct that i need to fit an Xbee RS232 adapter? as below, if so do i simply plug in or does it need, software installed ?

RS232 plugin


Thanks 
Kevin
 
 

clive1
replied 3 weeks ago

That would allow for NMEA sentences from UART2
How would you get RTCM3 data?

kevinemslie
replied 3 weeks ago

That was going to be my next question, as I was thinking of using the 4G NTRIP master also to receive NTRIP corrections.
So how can I receive NTRIP corrections and sent out RTK NMEA ?

clive1
replied 3 weeks ago

You’d have to push data you’ve already sourced down the input RS232 channel.

For a stacked model, you’d want to be using the Lite board, and start with RS232 at the bottom. ie RS232 + Lite + NTRIP 4G

https://www.ardusimple.com/product/rs232-to-xbee-everything-adapter-3m-cable/”

The Lite board has different UARTs connected to the bottom pins vs top socket

kevinemslie
replied 3 weeks ago

Ok, that’s sounds like what I need.
Just double checking but i see there is RX and TX connectors on the Simple RTK2B board, is that not an NMEA out put ?

clive1
replied 3 weeks ago

Yes, but you’d need to wire them more explicitly, to some other type of CMOS to RS232 adapter.
RX1, TX1 (output), IOREF (TO 3V3), and GND
NMEA can be output from UART1

kevinemslie
replied 2 weeks ago

Hi, I have ordered and received the RS232 to everything and the lite, i have them connected together, connected the power to a 12 volt supply and ground, antenna is connected and the GPS FIX LED is flashing but when i connect the RS232 (DB9) connector to my GPS terminal i do not get any NMEA messages.
Also i cant get this unit to connect to U-center to check firmware etc, i am connected to the mico USB on the RS232 to everything board.

kevinemslie
replied 2 weeks ago

Hi, 

I have managed to get the “RS232 to everything” and the “lite” connected to U-centre i have connected the RS232 (DB9) connector to another PC with Tera Term installed to view the messages.

I can now see that the messages “talker ID” is set to GN but i need it set to GP.

I see where to change the message in U-centre but it doesn’t save, when i disable GN and then enable GP, it just reverts back to GN. 

How do i get the talker ID to stay on GP ? 

clive1
replied 2 weeks ago

If using UBX-CFG-NMEA, you’d likely want use UBX-CFG-CFG to save into FLASH

Alternatively there might be a configuration key approach, where you specify the key goes into FLASH

20930031 CFG-NMEA-MAINTALKERID
20930032 CFG-NMEA-GSVTALKERID
30930033 CFG-NMEA-BDSTALKERID

kevinemslie
replied 2 weeks ago

Too many acronyms in there for me Clive, could explain that better to me please.

clive1
replied 2 weeks ago

Using uCenter Classic(ie 22.07)
You can configure the device via “View -> Message View”, descending to the tree nodes of the appropriate commands and configuration items

Keys via “View -> Generation 9 Configuration View’

The manual describes the supported functionalities, and commands/configuration
https://content.u-blox.com/sites/default/files/documents/u-blox-F9-HPG-1.32_InterfaceDescription_UBX-22008968.pdf

kevinemslie
replied 2 weeks ago

Hi, i have figured out what you said above with trial and error, i then needed to find and change the baud rate and the Hertz which i have done.
It is still not working properly, i think i need to change the amount of numbers after the decimal place on the Coordinates of the GGA sentence.
I need 7 digits after the decimal place on the GGA sentence.
How do i change the amount to digits after the decimal place on the GGA sentence ?

clive1
replied 2 weeks ago

Via UBX-CFG-NMEA High Precision option
or
CFG-NMEA-HIGHPREC 0x10930006

kevinemslie
replied 2 weeks ago

Got it, thank you

kevinemslie
replied 7 days ago

I have this working, my only issue is I cant get a heading/course to appear in the GPVTG message sentence unless the rover is moving.
Is there a setting we can change to get the heading/course to show in the VTG when the rover is stationary ?

clive1
replied 6 days ago

The GPS/GNSS antenna is not directional, signals are incident from all directions.

You have to move from A to B, tells you how the vehicle is moving, not the direction it is pointing, although this tends to follow for ground vehicles, it’s not true for boats or planes.

Orientation systems use TWO antennas, or more, and the direction is determined via relative position of each, and geometry, whilst static or moving.

kevinemslie
replied 1 day ago

Hi, I’m at the final stages of this project, I have the RS232 to everything + Simple RTK2Blite + 4G NTRIP Master all connected, i can get an RTK fix when its all connected to U-centre but as soon as I close U-centre or disconnect the receiver from the PC I loose RTK.
So when i follow the hook up guide, it says to make a configuration file and use the configuration tool to install it but when I do this, the install always fails, i have also tried to install the software but it fails also.
I have also read that the 4G NTRIP Master is not compatible with the RTK2B lite, is this correct ?

Want to learn more about GPS/RTK?

1. Our engineering team will contact you to solve any questions
2. We will keep you updated about promotions and new product releases
3.You will only hear from us when we have important news, we won’t spam your email