Hey, I am using sparkfun ublox GPS-RTK2 and GPS-RTK SMA breakout boards, i have tried every configuration starting from TMODE3 ,PRT, MSG etc in both the boards ,but im not able to get heading from RTK-2 board ,i m using uart2 for receiving RTK corrections, even in uprecise i can see the incoming RTCM packets ,but still when i navigate to NAV and then go to RELPOSNED ,it doesn’t show heading ….but the same module when connected to ucentre shows flag as 2 which represents differential mode ,but it never turn into RTK FIXED. HELP!
Hi Manika (@manika_panchal ),
Please see the u-blox application note below. Please check you have enabled all the messages listed in section 2.2.
I hope this helps,
Paul
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Thank you …will get back if i encounter any problem………
Here are some diagrams/illustrations I’ve previously posted to the uBlox forum.
For a first-order solution, one typically gets position from one unit, and orientation/direction from the second unit.
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hey ..firstly i want to thank you for providing this information, the modules started working ….but now i’m encountering one more problem …and its that i can see heading in the ucentre software …but i want to fetch the heading using NMEA and i can read heading from $HDT frame …but as i’m using HPG-1.51 Firmware …i’m not able to set $HDT frame in ucentre as its not available in this firmware version…can u please suggest something…
Hi @manika_panchal ,
I don’t think the RELPOSNED heading information is available in NMEA format. Only in the binary UBX-NAV-RELPOSNED message…
I hope this helps,
Paul
There isn’t a NMEA heading message that the receiver supports.
You either need to process the two streams using UBX messages, or feed to an MCU solution that can combine the feeds and output an equivalent NMEA message for legacy equipment.
Thank you for the useful info, so lately I’ve been facing this issue where I’m not able to receive UBX packets from RTK 2 board via uart1, I’m using uart2 for RTCM corrections, my end goal is to get heading value over UART/I2C so that I can further process it. I have done some settings in RTK2 board like on uart1 instead of NMEA now I have set protocol out as UBX+NMEA ,but still I’m only receiving NMEA packets on serial port. HELP!
Hi @manika_panchal ,
It might be safest to clear your configuration back to the defaults and start again? You need to be careful with the port protocols, especially if you are configuring over that same port. If you disable UBX output, you will receive no UBX messages - including the UBX acknowledgments of any UBX messages you send into the port. If you disable UBX input, the GNSS will ignore any UBX commands you send into the port.
I hope this helps,
Paul
It outputs several NMEA messages by default. You have to enable individual UBX messages for periodic output if you expect to see them.
Perhaps diagram exactly what you have built and how you are configuring each unit.
I have also enabled UBX_NAV_RELPOSNED MSG on UART1
Hi @manika_panchal ,
How are you configuring the two ZED GNSS modules? Over USB? Or over UART?
Please tell us what Protocol In and Protocol Out are on all ports.
Best,
Paul
Ok, and are you seeing and successfully parsing the UBX-NAV-RELPOSNED ?
Can you record and furnish the data stream you’re seeing on the STM32, or feed it thru to another serial port / uart for inspection.
Can you show the code, or portion of it, responsible for configuring the output of UBX-NAV-RELPOSNED ?
Make sure the Rover has UART2 PROTOCOL OUT:NONE
I’m configuring the two modules using ucentre via USB.
Even after enabling the UBX-NAV-RELPOSNED, I’m only receiving NMEA on UART1 but as per the config I should be getting UBX +NMEA.
Hi @manika_panchal ,
Perhaps you could try enabling another UBX message. I suggest UBX-NAV-PVT. If you are able to receive that, then you know you have a problem with the RTCM configuration. If you are not able to receive PVT, then you know you have a problem with the port protocol configuration.
Please check that both antennas are outdoors with a clear view of the sky.
I hope this helps,
Paul
What exactly are you sending to the receiver, show code, show any response, ie ACK-ACK or ACK-NAK.
It’s very hard to debug “not working” without some context as to what exactly is being done and other signs of what is happening.
here is the image which confirms that im getting UBX messages but on USB ,i have enabled it for both USB and uart1 ,here is the image how i have configured it….now when im printing the received bytes on stm ..it shows only nmea no UBX
Hi @manika_panchal ,
Please tell us what Protocol In and Protocol Out are on all ports - on both ZED-F9Ps.
Please post screenshots for UBX-CFG-PRT, showing UART1, UART2 and USB.
Thank you,
Paul
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