Need help connecting to MQTT using nRF9160

[pranav-ether]

I can't figure out what I'm missing. I'm not able to send messages using MQTT.

Here's the link to my code: https://github.com/pranav-ether/test/tree/main/mqtt_pub

This are the logs:

[00:02:58.031,768] <inf> LTE: Network registration status: Connected - home network
[00:02:58.031,890] <inf> LTE: Connected to LTE network
[00:02:58.031,921] <inf> LTE: ====== Cell Network Info ======
[00:02:58.033,477] <inf> LTE: Signal strength: 42
[00:02:58.034,210] <inf> LTE: Current LTE band: 8
[00:02:58.034,912] <inf> LTE: Supported LTE bands: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)
[00:02:58.035,705] <inf> LTE: Tracking area code: 8CA1
[00:02:58.036,468] <inf> LTE: Current mode: 0
[00:02:58.037,200] <inf> LTE: Current operator name: 65501
[00:02:58.038,146] <inf> LTE: Cell ID of the device: 0E446D21
[00:02:58.039,337] <inf> LTE: IP address of the device: 100.67.202.179
[00:02:58.039,886] <inf> LTE: Modem firmware version: mfw_nrf9160_1.3.5
[00:02:58.040,618] <inf> LTE: LTE-M support mode: 0
[00:02:58.041,259] <inf> LTE: NB-IoT support mode: 1
[00:02:58.041,900] <inf> LTE: GPS support mode: 0
[00:02:58.042,633] <inf> LTE: Mobile network time and date: 24/08/13,06:33:37+08
[00:02:58.042,633] <inf> LTE: ===============================
[00:02:58.043,121] <inf> MQTT: Connection to broker using mqtt_init
[00:04:23.972,839] <err> mqtt_helper: Cloud MQTT keepalive ping failed: -128

[Charlie]

Did you make original NCS MQTT sample works MQTT (nordicsemi.com)? Which NCS version are you based on?

[pranav-ether]

The mqtt sample did not work for me. I'm using v2.6.1
Here are the logs for the mqtt sample:

[00:00:00.295,349] <inf> network: Bringing network interface up and connecting to the network
[00:00:00.528,198] <inf> nrf_modem_lib_trace: Trace thread ready
[00:00:00.535,827] <inf> nrf_modem_lib_trace: Trace level override: 2
+CEREG: 2,"8CA1","0E241F17",9
+CSCON: 1
+CSCON: 0
+CSCON: 1
+CGEV: ME PDN ACT 0,0
+CNEC_ESM: 50,0
+CEREG: 1,"8CA1","0E241F17",9,,,"11100000","00000110"
[00:01:47.830,474] <inf> network: Network connectivity established
[00:03:30.036,132] <err> mqtt_helper: Cloud MQTT keepalive ping failed: -128
[00:03:30.036,376] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:03:30.036,407] <err> transport: Failed connecting to MQTT, error code: -95
[00:04:30.037,017] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:04:30.037,048] <err> transport: Failed connecting to MQTT, error code: -95
+CSCON: 0
[00:05:30.046,081] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:05:30.046,112] <err> transport: Failed connecting to MQTT, error code: -95
+CSCON: 1
[00:06:30.046,875] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:06:30.046,905] <err> transport: Failed connecting to MQTT, error code: -95
+CSCON: 0
[00:07:30.055,938] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:07:30.055,969] <err> transport: Failed connecting to MQTT, error code: -95
[00:08:30.065,032] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:08:30.065,063] <err> transport: Failed connecting to MQTT, error code: -95
*** Booting nRF Connect SDK 3758bcbfa5cd ***
[00:00:00.300,537] <inf> network: Bringing network interface up and connecting to the network
[00:00:00.533,386] <inf> nrf_modem_lib_trace: Trace thread ready
[00:00:00.541,015] <inf> nrf_modem_lib_trace: Trace level override: 2
+CEREG: 2,"8CA1","0E241F17",9
+CSCON: 1
+CSCON: 0
+CSCON: 1
+CGEV: ME PDN ACT 0,0
+CNEC_ESM: 50,0
+CEREG: 1,"8CA1","0E241F17",9,,,"11100000","00000110"
[00:01:49.906,158] <inf> network: Network connectivity established
[00:03:32.047,851] <err> mqtt_helper: Cloud MQTT keepalive ping failed: -128
[00:03:32.048,095] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:03:32.048,095] <err> transport: Failed connecting to MQTT, error code: -95
[00:04:32.048,706] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:04:32.048,736] <err> transport: Failed connecting to MQTT, error code: -95
+CSCON: 0
[00:05:32.057,800] <err> mqtt_helper: Library is in the wrong state (MQTT_STATE_CONNECTING), MQTT_STATE_DISCONNECTED required
[00:05:32.057,830] <err> transport: Failed connecting to MQTT, error code: -95

[pranav-ether]

I'm trying to figure out why it's not connecting to the network, the ISP says the SIMs are fine. When I try using Modem Shell to connect manually, I'm getting few errors. It would be great if you can help me connect to the network. Please check if the way I'm adding APN details are correct. I have attached the trace file of the Modem Shell, hope that helps.

mosh:~$ > link connect --apn "airteliot.com" -f 'ipv4v6' -A 0 -U "" -P ""
link connect --apn "airteliot.com" -f 'ipv4v6' -A 0 -U "" -P ""
pdn_activate() failed, err -8 esm 0 <unknown>

[00:01:03.817,352] <wrn> pdn: Failed to activate PDN for CID 1, err 65536
mosh:~$ > link funmode -1
link funmode -1
Release 14 features enable AT-command error, type 1 err 0
lte_lc_system_mode_set returned error -14
Functional mode set successfully: normal
[00:01:14.231,323] <err> lte_lc: Could not send AT command, error: 65536
mosh:~$ > link sysmode -n --pref_nbiot
link sysmode -n --pref_nbiot
Cannot set system mode to modem: -14
Requested mode couldn't set to modem. Not in flighmode nor in pwroff?
sysmode 2 saved successfully to settings
LTE preference 2 saved successfully to settings
[00:01:21.959,320] <err> lte_lc: Could not send AT command, error: 65536
mosh:~$ > link connect --apn "airteliot.com" -f 'ipv4v6' -A 0 -U "" -P ""
link connect --apn "airteliot.com" -f 'ipv4v6' -A 0 -U "" -P ""
pdn_activate() failed, err -8 esm 0 <unknown>

[00:01:27.975,372] <wrn> pdn: Failed to activate PDN for CID 1, err 65536
Modem domain event: Search done
Network registration status: searching
LTE cell changed: ID: -1, Tracking area: -1
mosh:~$ > link funmode --normal_no_rel14
link funmode --normal_no_rel14
Release 14 features disable AT-command error, type 1 err 0
lte_lc_system_mode_set returned error -14
Functional mode set successfully: normal
[00:02:51.416,839] <err> lte_lc: Could not send AT command, error: 65536
Network registration status: unknown
Network registration status: searching

trace-2024-09-13T09-38-29.062Z.mtrace

[Charlie]

(+) How to Activate the nRF Cloud using Airtel M2M sim card? - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

(+) steps for lte registration. - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

(+) Verification failed - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

Mobile IoT Deployment Map | Internet of Things (gsma.com) shows only JIO supports NB-IoT in India. Please have a try with JIO NB-IoT network.

Best regards,

Charlie

[pranav-ether]

Airtel says that the SIMs they've sent are NB-IoT SIMs.
But this confirms that there is no Airtel signal right? Is there any other ways of pin pointing the issue?
I'm not able to fine LTE Link Monitor app on nRF Connect. Any idea why? I'm using Linux and the latest appimage.

mosh:~$ > at AT%COPS=?
at AT%COPS=?
%COPS: (1,"","","405861",9)
OK

Network registration status: searching
LTE cell changed: ID: -1, Tracking area: -1
Currently active system mode: NB-IoT
LTE cell changed: ID: 2894737, Tracking area: 49173
mosh:~$ > at AT%COPS=?
at AT%COPS=?
Currently active system mode: None
%COPS: (1,"","","405861",9)
OK

LTE cell changed: ID: -1, Tracking area: -1
RRC mode: Connected
Currently active system mode: NB-IoT
LTE cell changed: ID: 6032786, Tracking area: 49173
RRC mode: Idle
Modem domain event: Search done
mosh:~$ > at AT%COPS=?
at AT%COPS=?
Currently active system mode: None
%COPS: (3,"","","405861",9)
OK

LTE cell changed: ID: -1, Tracking area: -1

[Charlie]

Yes, only JIO network is found by your device according to AT%COPS=? feedback.

MCC	MNC	PLMN	Region	Country	ISO	Operator	Brand	TADIG	Bands
405	861	405861	Asia and the Middle East	India	IN	Karnataka	Jio	INDJ9	LTE 850 / LTE 1800 / TD-LTE 2300

[pranav-ether]

I was able to get Jio SIMs and I'm able to connect to the network. But my MQTT program still doesn't work. It works only for brokers without username & password. The broker I want to connect to has username, password & port (My program is in the body of this post).

Also the network is getting connected on the nRF9160DK but not my custom board. What could be the reason?

[Charlie]

1) For the original sample  docs.nordicsemi.com/.../description.html, if you want to use username & password to connect with MQTT broker, you need to add username & password parameters here:

https://github.com/nrfconnect/sdk-nrf/blob/2bae3437305bc8f5eb29260ca545fb8033b2b80b/samples/net/mqtt/src/modules/transport/transport.c#L187

struct mqtt_helper_conn_params {

/* The hostname must be null-terminated. */

struct mqtt_helper_buf hostname;

struct mqtt_helper_buf device_id;

struct mqtt_helper_buf user_name;

struct mqtt_helper_buf password;

};

2) For your custom board connection issue, can you attach the log and modem trace?

[pranav-ether]

How do I get modem trace through RTT? My custom board does not have free UART ports for logging.

[pranav-ether]

I was able to get MQTT working with Jio in India. But the same firmware isn't working in South Africa with Vodacom NB-IoT. Here's the log and trace. I want to get the firmware working with the DK. I have opened another issue for my custom board connection problems.

trace-2024-10-04T06-22-12.925Z.mtrace

*** Booting nRF Connect SDK 3758bcbfa5cd ***
[00:00:00.496,185] <inf> nrf_modem_lib_trace: Trace thread ready
[00:00:00.503,814] <inf> nrf_modem_lib_trace: Trace level override: 2
[00:00:00.508,941] <inf> LTE: Connecting to LTE network
[00:00:00.511,077] <inf> LTE: lte_lc_system_mode_set: 0
[00:00:00.537,811] <inf> LTE: lte_lc_connect_async: 0
[00:01:54.258,575] <inf> LTE: Network registration status: Connected - home network
[00:01:54.258,697] <inf> LTE: Connected to LTE network
[00:01:54.258,728] <inf> LTE: ====== Cell Network Info ======
[00:01:54.260,284] <inf> LTE: Signal strength: 53
[00:01:54.261,047] <inf> LTE: Current LTE band: 8
[00:01:54.261,749] <inf> LTE: Supported LTE bands: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)
[00:01:54.262,542] <inf> LTE: Tracking area code: 8CA1
[00:01:54.263,214] <inf> LTE: Current mode: 0
[00:01:54.263,977] <inf> LTE: Current operator name: 65501
[00:01:54.264,923] <inf> LTE: Cell ID of the device: 0E241F17
[00:01:54.266,082] <inf> LTE: IP address of the device: 100.xx.xx.xxx
[00:01:54.266,632] <inf> LTE: Modem firmware version: mfw_nrf9160_1.3.5
[00:01:54.267,364] <inf> LTE: LTE-M support mode: 0
[00:01:54.268,005] <inf> LTE: NB-IoT support mode: 1
[00:01:54.268,676] <inf> LTE: GPS support mode: 0
[00:01:54.269,256] <inf> LTE: Mobile network time and date:
[00:01:54.269,256] <inf> LTE: ===============================
[00:01:54.269,714] <inf> MQTT: Connection to broker using mqtt_init
[00:02:06.240,570] <inf> MQTT: Successfully connected to MQTT broker
[00:03:06.240,753] <err> mqtt_helper: Cloud MQTT keepalive ping failed: -128