not getting 1.8 volt in "SIM_1V8" pin

[Balamurugan]

we have designed a board using Nrf9160 IC and we have issue with SIM module. we not getting 1.8 volt in "SIM_1V8" pin. when running mqtt sample program we are getting

"***** Booting Zephyr OS v1.14.99-ncs1-581-g98c2d76ddd29 *****

The MQTT simple sample started

LTE Link Connecting ...

LTE Link Connected!

ERROR: getaddrinfo failed 22

ERROR: mqtt_connect -47.

Actually sim is not inserted. and also inserting sim does not  make any difference. In dev board it is 1.8 volt in "SIM_1V8" and in our board its 0 volt.

In dev board for "AT%XSIM?" returning

AT%XSIM?

%XSIM: 1

OK

AT+CPIN?

+CPIN: READY

OK

AT+CPINR="SIM PIN"

+CPINR: "SIM PIN",3

OK

AT+CIMI

204080813510834

In our board for "AT%XSIM?" returning:

%XSIM: 0

OK

Pleas help us to resolve the issue.

Our schematic is attached.

NB_IOT_VER1.pdf

[Sigurd]

Hi,

Is the sim-card inserted the correct way? Some sim card sockets allows the card to be inserted both ways, but only one way will work.

Note that public MQTT brokers might be unstable. If you experience problems connecting to the MQTT broker, try switching to another broker by changing the value of the MQTT_BROKER_HOSTNAME configuration option (prj.conf). E.g. 

CONFIG_MQTT_BROKER_HOSTNAME="test.mosquitto.org"

You might want to test the at_client sample, and see if you are able to connect to the network using that sample also.

[Balamurugan]

Thanks for reply.

Board had assembly issue with "SIM_1V8" pin and IC re-flow solved it.Getting 1.8 volt in sim slot and SIM status is ok.

Between dev board and custom board we see diffidence in "Model identifier".

nRF9160 Dev board:

AT+CGMM
nRF9160-SICA
OK

Our Board with nRF9160 IC:

AT+CGMM

nRF9120

OK

Please let us know is this expected.?

[Sigurd]

Hi,

Balamurugan said:

Board had assembly issue with "SIM_1V8" pin and IC re-flow solved it.Getting 1.8 volt in sim slot and SIM status is ok.

Great!

Balamurugan said:

Please let us know is this expected.?

Yes, it's expected for some of the older versions of the modem firmware. If you update to the latest modem fw(0.7.0-29.alpha as of today), it should also output nRF9160-SICA. 

[Balamurugan]

Thanks. After modem firmware update it is returning "nRF9160-SICA" . Also mqtt sample program works  similar as it works in dev board. i do not  see false positive "LTE Link Connected!" message.

Thanks...  Issues solved.