Can't connect to network with mqtt nor at_command. No AT command is working and the system crashes and restart

[jonathankongolo]

Hi, We did design our own board/pcb using the nrf9160, but we have a problem to connect to network/lte. I did some debugging and I found out that when the method lte_lc_init_and_connect() is call, the board crashes and restart. To connect to network (lte) we are using the port 20, 30, 31, where port 20 is connected to COEX2 and must be HIGH. (using mqtt sample)

So, I did run the sample at_client to see if I could make small request with AT command, but only the command "AT" gives an answer "OK". And all other at command gives nothing and sometime the At command "AT+CFUN?" gives "ERROR" (first time run after reset)

I do not know now where to look to make it work, do someone has answer for this issue ? :(

thank you

[Håkon Alseth]

Hi,

 

Hi, We did design our own board/pcb using the nrf9160, but we have a problem to connect to network/lte. I did some debugging and I found out that when the method lte_lc_init_and_connect() is call, the board crashes and restart. To connect to network (lte) we are using the port 20, 30, 31, where port 20 is connected to COEX2 and must be HIGH. (using mqtt sample)

Do you include a sequence that provides this configuration when testing your firmware?

What do you mean by "port x" ? Do you mean GPIO P0.20, P0.30 etc? Do you have a schematic snippet or something that I can look at?

So, I did run the sample at_client to see if I could make small request with AT command, but only the command "AT" gives an answer "OK". And all other at command gives nothing and sometime the At command "AT+CFUN?" gives "ERROR" (first time run after reset)

You are on the right track here, but you should issue "AT+CFUN=1", followed by "AT+CFUN?". This should apply automatic requests, which enables more verbose errors etc.

If you get an error response in the PC application (ie. a serial comm issue), try resetting the application (CTRL+R in LTE Link Monitor) and the nRF9160 board.

 

Kind regards,

Håkon