Can’t access NMEA stream from rm520 in pcie mode

IoT Modules 5G Module
1

When I put the rm520 into pcie data mode the NMEA stream on ttyUSB1 stops.
How can I get it back?

Thanks.

2

Dear @steely-glint
Could you send AT commands now? Please confirm if you can detect device.

3

Hello, yes, I can see the device - and I’ve mod loaded a serial driver

khadas@k4:/dev$ ls /dev/ttyUSB*
/dev/ttyUSB0  /dev/ttyUSB1  /dev/ttyUSB2  /dev/ttyUSB3

The network is up.

khadas@k4:/dev$ ifconfig rmnet_mhi0.1
rmnet_mhi0.1: flags=193<UP,RUNNING,NOARP>  mtu 1472
        inet 192.0.0.2  netmask 255.255.255.224
        inet6 2a01:599:10c:9542:b4ac:a1c:7d83:435a  prefixlen 64  scopeid 0x0<global>
        inet6 2a01:599:10c:9542:50:f4ff:fe00:0  prefixlen 64  scopeid 0x0<global>
        ether 02:50:f4:00:00:00  txqueuelen 1000  (Ethernet)
        RX packets 30  bytes 3497 (3.4 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 56  bytes 6531 (6.5 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

And I can send AT commands

khadas@k4:/dev$ sudo minicom -D /dev/ttyUSB2




Welcome to minicom 2.8

OPTIONS: I18n 
Port /dev/ttyUSB2, 09:42:29

Press CTRL-A Z for help on special keys

AT+QGPS=1 
+CME ERROR: 504

and get GPS LOC on demand.

AT+QGPSLOC=0
+QGPSLOC: 105653.00,XXXX.0728N,XXXX.6277E,2.5,38.4,3,,0.0,0.0,070923,08

But no stream on /dev/ttyUSB1

Welcome to minicom 2.8

OPTIONS: I18n 
Port /dev/ttyUSB1, 10:56:25

Press CTRL-A Z for help on special keys

If I switch to USB data mode I get the stream NMEA on ttyUSB1

Is there somewhere else I can read the NMEA stream ?

@silvia

Thanks.

Tim.

4

@silvia Hi, any progress on this question?

To re-state it:
If I set pcie mode for my high speed data link using
AT+QCFG=“data_interface”,1
and quectel-CM

I stop getting the GNSS NEMA data stream on /dev/ttyUSB1

(ttyUSB2 still accepts AT commands)
Can you help ?

Thanks.

5

Dear @steely-glint
Did you check the output port via AT+QGPSCFG=“outport”?

6

Dear @steely-glint
Could you check if your device show any /dev/mhi*?

7

@silvia Here’s the output you requested:

AT+QGPSCFG="outport"
+QGPSCFG: "outport",usbnmea

OK

and

khadas@k4:~$ ls -l /dev/mhi*
crw------- 1 root root 506, 0 Sep 20 14:43 /dev/mhi_BHI
crw------- 1 root root 507, 1 Sep 20 14:43 /dev/mhi_DIAG
crw------- 1 root root 507, 3 Sep 20 14:43 /dev/mhi_DUN
crw------- 1 root root 507, 0 Sep 20 14:43 /dev/mhi_LOOPBACK
crw------- 1 root root 507, 2 Sep 20 14:43 /dev/mhi_QMI0
khadas@k4:~$

Thanks for the quick reply.

Tim.

8

Dear @steely-glint
As checked internally, when use PCIE mode, nmea will output from /dev/mhi_LOOPBACK, please use this and test again.

9

Yes, that works !

Thank you for quick help.

Tim.