Several issues encountered with nrf9160 to AWS IOT

[Panda H]

Hi,

We modified the lte_ble_gateway example and connected to our aws iot server. And have faced few issues so far and would like to get some hint from you.

We are using mfwnrf9160100 firmware and NCS V1.0.0.

1. MQTT: Seems the mqtt link becomes unstable and there is no puback returned from AWS IOT after sending data few rounds, when sending data interval is 10 minutes, even when mqtt_live and mqtt_input are called every 3 minutes. The mqtt_keep_alive was set to 1200 during mqtt_connect. But the link becomes much stable after reducing the sending data interval to 5 minutes. We would like to be able to send data every hour while ping mqtt every 10 or 20 minutes to keep the mqtt link alive.

2. MQTT: Even the CONFIG_MQTT_KEEPALIVE is set to 1200, we are not able to maintain the mqtt link stable even when we call mqtt_ping every 10 minutes.

3. BSD: getting ERROR_BSD_RECOVERABLE: 3 when sending data interval is 10 minutes

4. LTE_LC: Seems the application is not able to exit lte_lc_power_off() if the lte link is dropped accidentally? I have to force rebooting the application when the lte link is lost, instead of power off the modem first.

5. DEBUG: even when log_level is set to 4 for mqtt module and other modules, debug output will be printed in LTE_LINK_MONITOR app. But after LTE link and mqtt link are established, all debug output are gone and there is only output from main printk function.

It is really a good product and looking forwards to your reply!

Thanks a lot! 

[Didrik Rokhaug]

Hi.

Can you try to update to the newest modem firmware version (v1.0.1) and see if that helps?

Regarding your point number 4. Does the modem automatically enter power off when losing connection, or are you setting it in power off?

When the modem enters power off, you have to reboot for it to turn on again. If you are setting it to power off, you probably want to set it to offline instead.

Best regards,

Didrik

[Panda H]

Shall I use modem firmware V1.0.1 with NCS master branch, or with NCS 1.0.0 tag?

Regarding to number 4, it is called when there is ERROR_NRF_CLOUD, as shown in lte_ble_gateway sample. But you are right, I shall set it to offline at least before modem is power on again.

[Didrik Rokhaug]

The new modem firmware works with both NCS v1.0.0 and master.

If the modem is set to power off, the only way to restart it is to do a reboot. Depending on your error handling, you might want to do that regardless of what error you receive, as they do in lte_ble_gateway.

If you do not want to reboot, just disconnect from the network/disable LTE-M/NB-IoT/GPS functionality what you want is to set the modem in offline-mode.