LC29HEA - problem getting heading information from moving base and rover configuration

IoT Modules GNSS Module
1

Hello,

I am using two LC29HEA modules and connecting them to get one working as mobile base and other as rover according to the “quectel_lc29hea_moving_base_application_note_v1-0” document.

I am using NTRIP to inject the corrections in the moving base and I am able to get RTK precision (both fixed and float quality indicator).

The problem is that I am not able to get heading information.
The procedure I followed was:

  1. Connecting both modules according to the moving base application note document
  2. Sending the command “$PQTMCFGMSGRATE,W,PQTMTAR,1,109" to the rover module to enable “$PQTMTAR” messages. The modules answers with "$PQTMCFGMSGRATE,OK29” but it never outputs “PQTMTAR” messages on its NMEA output. Also, the NMEA output from the moving base does not have heading information.

Can someone help with this? Do I need to do anything else to make this work?

Thanks in advance.
Best regards,
André

2

Hi andre.s.aguiar

  1. Please provide a log captured since the module was powered on.
  2. Please use the “$PQTMVERNO*58” command to check the version of the module and let me know
  3. Please take a picture of the connection diagram of the two LC29HEA modules, mark Base and Rover, and provide a connection diagram between Base and computer.
3

The same here. No PQTMTAR

Firmware version:
FW $PQTMVERNO,LC29HEANR11A03S_RSA,2023/10/31,16:52:14*2B

Hardware wire connected:
Base UART2 RX/TX is connected to Rover UART1 TX/RX

Both boards are configured as rover:
$PQTMRESTOREPAR13
$PQTMCFGRCVRMODE,W,12A
$PQTMSAVEPAR5A
reset
$PQTMCFGNMEADP,W,3,8,3,2,3,239
$PAIR050,20021
$PQTMSAVEPAR5A

PQTMTAR is enabled:
String: $PQTMCFGMSGRATE,W,PQTMTAR,1,109
$PQTMCFGMSGRATE,OK29

I checked both boards getting Fixed RTK with ntrip. Works fine.
But no heading output.
What am I missing?

regards

4

Hi @Hein_Bol
After the hardware connection is completed, do not send the following three commands.
Both boards are configured as rover:
$PQTMRESTOREPAR13
$PQTMCFGRCVRMODE,W,12A
$PQTMSAVEPAR5A

5

I never get PQTMTAR messages, allthough PQTM messages are working:

$PQTMEPE,2,0.2465,0.2680,0.4474,0.3641,0.5769*63

Could someone please send me his configuration for two separate modules?

I despair. No ideas anymore. :face_with_symbols_over_mouth:

Thanks

6

Same here. I have the same configuration and the hardware connections that are described in the LC29HEA manual but PQTMTAR messages do not appear.

7

So we have to do this by ourselves. That sucks but ok.
I will use an ESP32. Feed both LC29HEA with correction data and compute the heading.
I hoped I could avoid this stupid part.

8

Hi @Hein_Bol and @andre.s.aguiar
PQTMTAR Only when two activated LC29HEAs are correctly connected, can the PQTMTAR message be opened by command “$PQTMCFGMSGRATE,W,PQTMTAR,1,1*09”.
Please refer to the figure below for connection.

image
image903×885 79.6 KB

If you need to obtain more information, please provide your email address.

9

@george.gao I have two LC29HEAs correctly connected as in the picture. I verified all the connections and checked that the data is flowing:

→ External corrections to LC29HEA (Base)
→ Local corrections from LC29HEA (Base) to LC29HEA (Rover)

I sniffed the local corrections and they do not seem to be pure RTCM. Is this normal?
Can you send me your email? Perhaps we can schedule a meeting.

Thanks in advance.

10

Hi @andre.s.aguiar
Did you send “$PQTMCFGMSGRATE,W,PQTMTAR,1,1*09” and there was no PQTMTAR output?
I sent you my email privately.

12

If you have this module, it has no exposed uart2. You have to solder wires (green marks).

-1766820907-394849436~3
-1766820907-394849436~3390×559 51.7 KB

13

Now it works.

Attention: Baudrate Base(uart2)-Rover(uart1) is 921600 after Base has configured the Rover !!!

The Rover gives:
$PQTMVEHATT,1,1723384753.0000,14
$PQTMTXT,1,01,01,01,1723384753.0000,1,24,0.0000,0.0000,0.0000,0.0000,0.00007E
$PQTMTAR,1,135913.000,1,0.000,24*65

But, never mind.

And the Base gives:
$PQTMTAR,1,141020.200,5,2.195,-1.043460,130.403849,29.896879,19.406567,31*4F

:grinning: :+1:

14

Hi @Hein_Bol

Can you please tell me the exact steps that you used to make it work?

Regarding the baudrate, did you have to change it either on the base or on the rover?

Thanks in advance

15

Look at my image and solder wires to the green marked pins. Right is RDX2, left TXD2. Connect them to the second board TXD1/RXD1, additional connect GND. The switches on the base module must be in position like in the image, on the rover module in the opposite direction.
Power on the rover and connect the base with your pc.
Send $PQTMCFGMSGRATE,W,PQTMTAR,1,1*09 to the base.
That’s it.
Maybe reset both boards before:
$PQTMRESTOREPAR13
$PQTMSAVEPAR5A
Connect to your NTRIP caster and wait for the Fix RTK.