We have an interesting difficulty, whereby after a period of time which varies never longer than 12 hours, often around 6 hours, our application disconnects from the network and attempts to reconnect and never manages to.
We are using V1.0.0 and the latest modem firmware and Segger running on Windows 10.
We are using a modified version of lte_ble_gateway.connecting to AWS
The connection is CAT M1 and our software is running on a nRF9160-DK (Version 0.8.5)
Our log (attached) shows that the modem is unresponsive at the time or after the disconnect as evidenced by the AT command at the end of the log.
The operative two lines of code that should get executed are as follows:
It seems like the write of AT+CFUN=0 never returns due to the modem being (kind of ) dead for whatever reason.
Therefore it may follow that the bsd_shutdown(); never happens.
err = lte_lc_power_off();
bsd_shutdown();
We can imagine that everything else seems to be OK, as we continue to receive data from the UART whilst in a disconnected state.
To make matters even more interesting, if we connect to a different carrier it seems that the problem almost evaporates. I say almost as we have had our software running for many days now at two sites, one of which required a reset, whilst the other continues without failure.
I know you will ask me for a modem trace which I'm currently in the process of capturing.
If the nRF9160-DK is reset it will run for another few hours, before failure.
Another question that I have is would you please explain if there is any difficulty/danger in replacing the modem shutdown and reboot with the following:
sys_reboot(SYS_REBOOT_COLD);
My concern is that if the modem is constantly wring to NVM and our timing was "perfect" is there the possibility of corrupting the modem flash?
