Hello William,

Thanks for your feedback.

Yes please find below output in my console:

SEGGER J-Link V6.48 - Real time terminal output

J-Link OB-SAM3U128-V2-NordicSemi compiled Jan  7 2019 14:07:15 V1.0, SN=682005484

Process: JLinkExe

[00:00:00.677,947] <inf> modem_ublox_sara_r4: Setting Modem Pins

[00:00:10.878,143] <inf> modem_ublox_sara_r4: ... Done!

[00:00:10.878,173] <inf> modem_ublox_sara_r4: Waiting for modem to respond

[00:00:25.453,521] <inf> modem_ublox_sara_r4: Manufacturer: AT+CGMI

[00:00:25.454,284] <inf> modem_ublox_sara_r4: Manufacturer: u-blox

[00:00:25.510,009] <inf> modem_ublox_sara_r4: Model: AT+CGMM

[00:00:25.511,474] <inf> modem_ublox_sara_r4: Model: SARA-R412M-02B

[00:00:25.567,169] <inf> modem_ublox_sara_r4: Revision: <log_strdup alloc failed>

[00:00:25.570,129] <inf> modem_ublox_sara_r4: Revision: <log_strdup alloc failed>

[00:00:25.625,823] <inf> modem_ublox_sara_r4: IMEI: <log_strdup alloc failed>

[00:00:25.627,380] <inf> modem_ublox_sara_r4: IMEI: <log_strdup alloc failed>

[00:00:25.776,062] <inf> modem_ublox_sara_r4: Waiting for network

[00:00:27.782,928] <inf> modem_ublox_sara_r4: RSRP: -1000

[00:00:29.790,222] <inf> modem_ublox_sara_r4: RSRP: -1000

[00:00:31.797,546] <inf> modem_ublox_sara_r4: RSRP: -88

[00:00:33.798,065] <inf> modem_ublox_sara_r4: Network is ready.

[00:00:33.798,248] <err> modem_ublox_sara_r4: NET_SOCKET_OFFLOAD must be configured for this driver

[00:00:33.798,248] <wrn> net_dns_resolve: Cannot initialize DNS resolver (-134)

***** Booting Zephyr OS build zephyr-v2.0.0-41-g94019097bb8c *****

[00:00:34.842,803] <inf> net_config: Initializing network

[00:00:34.842,864] <inf> net_config: IPv4 address: 83.166.154.87

attempting to connect: socket_id:0 left_bytes:4 err: 4

MQTT connect failed -111

socket_id:1 left_bytes:4 err: 4

I can see that Network connection is ok MQTT server is not reachable.

For your information, I achieved to make it works with previous revision of SARA R4 driver.
It does not work after the following commit : https://github.com/zephyrproject-rtos/zephyr/commit/ebf6520d8713aae9809eb1ef6bee7211cf9b4caa#diff-cb3c7d77935fa5df6ccb74a1c5e050ba

I also made some debug on UART bus and I saw something strange on +UUSORD unsolicited answer management

This section is working

AT+USOCR=6,47069

+USOCR: 1

OK

AT+USOCO=1,"83.166.154.87",1883

OK

AT+USOWR=1,30

@

+USOWR: 1,30

OK

+UUSORD: 1,4

AT+USORD=1,4

+USORD: 1,4,"20020000"

OK

AT+USOWR=1,2

@

+USOWR: 1,2

OK

+UUSORD: 1,2

AT+USORD=1,2

+USORD: 1,2,"D000"

OK

….

This section is not working and we can see that +UUSORD does not come at the good moment.

AT+USOCR=6

+USOCR: 0

OK

AT+USOCO=0,"83.166.154.87",1883

OK

AT+USOWR=0,30

@

+USOWR: 0,30

OK

AT+USOWR=0,30

@

+USOWR: 0,30

OK

AT+USOWR=0,30

@

+USOWR: 0,30

OK

+UUSORD: 0,4

AT+USOWR=0,30

@

+CME ERROR: 3

Can you please let me know if SARA R4 is tested on MQTT or just on LWM2M example ? (I did not try this last one because I have not any LWM2M server available).

I hope my mail is clear enough (I know it is a bit long 😊)

Really thanks for your help

Rgds

Guillaume

De : devel@... <devel@...> De la part de William Fish via Lists.Zephyrproject.Org
Envoyé : mercredi 8 janvier 2020 12:06
À : devel@...
Cc : devel@...
Objet : Re: [Zephyr-devel] [MQTT/SARAR4] Issue during MQTT publish

Hi Guillaume,
Do you have the debug output showing

• The R4 connection to network?
• Connection to MQTT server?

At first glance it appears that you aren't connected (Err 111: Connection refused).

This could be caused by a number of things. You may find that there have been some configuration changes in the SARA driver which could be effecting your connection.

Billy..