SIM never detected

ianjanicki

Hologram Hyper eUICC SIM is never detected by the modem. AT%XSIM? returns 0 at every CFUN state, AT+CPIN? returns CME ERROR 13.

Board: Circuit Dojo nRF9151 Feather
Modem FW: mfw_nrf91×1_2.0.3
SIM: Activated on Hologram dashboard, Global-3 profile, pending first connection

What I’ve tried:

Bare-minimum firmware (modem init + AT commands only, nothing else)
AT%XANTCFG=1 and CONFIG_MODEM_ANTENNA per at_client sample
LTE Link Control enabled (SDK-managed init)
AT%CSUS? confirms slot 0 (external SIM)
Polled %XSIM for 30+ min after CFUN=4 — never changes
Modem FW updated from 2.0.2 to 2.0.3
SIM cleaned and reseated
AT%XVBAT reads _4900mV (power OK)

Saw a Nordic DevZone thread where SIM_1V8 wasn’t coming up on some nRF9151 boards. Could that be the issue here? Don’t have a second board or alternate nano-SIM to cross-test right now.

jaredwolff

Hey ianjanicki
, thanks for the detailed writeup — that makes it much easier to dig in!

A few things to try and check:

Photo of the SIM in the socket — Could you share a photo of the SIM seated in the nano-SIM slot? We want to make sure the card is fully inserted and oriented correctly (gold contacts facing down, notch aligned). Even a slight misalignment can prevent detection.

Run AT+CFUN=1 before checking SIM status — Before polling AT%XSIM? or AT+CPIN?, try setting the modem to full functionality first:

   AT+CFUN=1

Then wait a few seconds and re-run your SIM status checks. CFUN=4 (airplane mode) may not fully power the SIM interface on some firmware builds.

Confirm modem FW version — Can you run the modem firmware version command and share the output?

   AT+CGMR

This will confirm the exact MFW string the modem is reporting, just so we’re on the same page.

Regarding the SIM_1V8 concern — that’s a valid thing to check and we want to rule it out. The steps above will help us narrow down whether this is a power/hardware issue or something on the modem init side. Let us know what you get!

ianjanicki

Thanks Jared! Here’s where we’re at:

Modem FW: mfw_nrf91×1_2.0.3 (confirmed via AT+CGMR)

CFUN=1 before SIM check: Already tried. Here’s the actual diagnostic output from a bare-minimum test app (just modem init + AT commands):

FW:mfw_nrf91×1_2.0.3
CSUS:%CSUS: 0
XSIM at CFUN=0: %XSIM: 0, CPIN: CME13
XSIM at CFUN=4: %XSIM: 0, CPIN: CME13
XSIM at CFUN=1: %XSIM: 0, CPIN: CME13
XVBAT: 4926mV

Polled %XSIM for 30+ minutes after CFUN=4 and after CFUN=1 — never changes from 0. Also tried with CONFIG_LTE_LINK_CONTROL=y (SDK-managed init) — same result.

Photo of SIM: (notch on bottom, left of this image)

jaredwolff

Do you have any phone/device that has a micro sim port? A newer cell phone should be able to at least establish connection (I’ve done it in the past). If you can pop it in and we can rule out the SIM.

ianjanicki

SIM works fine in an iPhone — reads ICCID, picks up AT&T carrier. Problem is on the board side, likely SIM_1V8 or holder contacts.

And Hologram registers it:

jaredwolff

Sounds good. I’ll get you a return label so I can take a further look at it.

jaredwolff

@ianjanicki can you confirm it never worked. Or it worked at one point and stopped.

ianjanicki

Never worked. The SIM has never successfully been detected by the modem across dozens of test attempts over several days.

I started with custom firmware (LTE + HTTP upload for a camera project), and when the SIM wasn’t detected, I systematically stripped everything down to isolate the issue:

Tried full firmware with LTE link controller — XSIM: 0
Disabled LTE_LINK_CONTROL and used manual AT commands — XSIM: 0
Updated modem firmware from 2.0.2 to 2.0.3 — XSIM: 0
Built a bare-minimum test app (literally just modem init + AT commands, no peripherals) — XSIM: 0
Tried with CONFIG_LTE_LINK_CONTROL=y matching your at_client sample — XSIM: 0
Cleaned and reseated the SIM multiple times — XSIM: 0
Polled AT%XSIM? for 30+ minutes continuously — never changes from 0
Confirmed SIM works perfectly in an iPhone (Hologram dashboard saw it connect)

Never once got %XSIM above 0 or a successful AT+CPIN? response.

For reference, everything else on the board works fine:

Modem: Boots, responds to all AT commands, reports FW version
nPM1300 PMIC: I2C communication works, LED control works
ADC: Battery voltage reads correctly (_4900mV)
SPI flash: No errors during boot
GPIO: 3.3V regulator enable (P0.31) works
Debug probe (RP2040): Flashing and memory reads work reliably

Only the SIM interface is non-functional.

AchimKraus

never worked

Please don’t get me wrong: in my experience, my feathers have been broken mainly by solder work (for now only the older ones with the nRF9160 got broken). And though your picture shows soldered headers, I guess the question mainly targets, if that error was also there before the headers get soldered. But maybe the feather haven’t been tested without those headers.

Did you order exactly one? If you have more than one, then I hope the others are working.

jaredwolff

He ordered the headers soldered. So that’s on us. I’ll check it out when it arrives. Hopefully it’s an easy fix. Thanks @AchimKraus!!

cloudwiser

Maybe too late but I have the same problem with AT+CPIN? in terms of the ERROR return…but
AT%XICCID and AT+CIMIreturn correctly so my (monogoto) SIM is found…and I can connect over GEO-NB

jaredwolff

https://docs.nordicsemi.com/bundle/ref_at_commands_nrf91x1/page/REF/at_commands/security/cpin_read.html

Unless your SIM specifically has a PIN it’s unlikely you need to do anything with this command. Since it’s responding appropriately to the ICCID command you should be good to go. If you need anything further feel free to create a new post

jaredwolff

The resolution for this post was to make sure the correct commands were run. The extra at prefix is necessary when running AT commands in the test image that gets shipped with the 9151 Feather.

at at+CFUN=41
uart:~$ at at+CFUN=41
OK

at AT%XICCID
uart:~$ at AT%XICCID
%XICCID: <YOUR ICCID>
OK

uart:~$ at AT%XSIM?
%XSIM: 1
OK

uart:~$ at AT+CEREG?
+CEREG: 5,5,“0608”,“00CC2911”,7,,,“11100000”,“11100000”
OK