Sim Card Not Inserted problems... | Telit Cinterion IoT Developer Community
May 21, 2016 - 1:00am, 15305 views
Hi all,
I have a custom board with an EHS6. We followed the hardware integration description but when we insert our sim card, the module does not seem to detect it. AT+CPIN? yields "+CME ERROR: Sim Card Not Inserted".
I confirm that the CCIO (Sim card card detect) goes high to 1.8V. However, CCVCC, the Sim card VCC line, is always stuck at 0V.
Is there any configuration I need to do in AT^SCFG or something? Hopefully I'm just missing something obvious.
Thanks,,
Matt
Hi to all,
I have custom design including EHS6. My device is using nanoSIM holder with option to populate embeddedSIM chip. Because of this the CCIN pin is pulled up to V180 via 10k resistor. Yet, there is no voltage present on CCVCC pin of EHS6, not even for a moment, I check with scope. Any ideas how to solve this problem?
Best regards
Hello,
According to the hardware description the CCIN signal is mandatory for applications that allow the user to remove the SIM card during operation. The CCIN signal is by default low and will change to high level if a SIM card is inserted. If unused it should be kept open.
I think that you should leave it unconnected if you don't use SIM card detect switch or remove the resistor if you use the switch.
Regards,
Bartłomiej
Hi Bartłomiej.
I check with our previous design that it is using the same model of Gemalto EHS6, difference is that this design has full size SIM holder with SIM Present detect switch build in. So when SIM is in holder and holder is close, V180 is establishing high logic state on CCIN input, those enabling CCVCC, CCIO, CCRST and CCCLK. If CCIN is in low logic state, those signals are not present. In our latest design as I mentioned before, we are using nanoSIM holder without SIM Present detect switch or, depending on varian, an embeddedSIM (eUICC). Now we are in prototyping stage. So I connected CCIN via 10k resistor to V180 to simulate SIM card present. But neither of signals from SIM interface are present, no CCVCC, no CCIO, no CCRST, no CCCLK. Both EHS6 modules have same firmware: 03.001. I attached pdf file with circuit diagram for reference.
Best regards
Mariusz Szczygiel
Senior Electronics Engineer
Microlise Ltd
Hello,
Thank you for additional information.
Still I think that you should try to remove the resistor and connect CCIN directly to V180 or leave the CCIN not connected.
Please be aware that if there will be a possibility to remove the nano SIM when the module is powered-up you should consider using the switch.
Have you connected the oscilloscope to the lines - is there no signal at all even for a short period? If so I'd start from the CCIN line.
Please also see the reference design for EHS5 module here: https://iot-developer.thalesgroup.com/documentation/example-schematic-eh...
Regards,
Bartłomiej
Hi Bartłomiej.
I connected CCIN to V180 directly, no resistor. SIM interface is starting for short periods, doing check for SIM, 1.8V (for 61ms), 0V(for 25ms), 3V(for 64ms), then goes permanently to 0V.
When SIM is not inserted into holder, there is also CCCLK signal present.
When SIM is inserted, CCCLK looks like single pulses following CCVCC.
when SIM is not inserted:
yellow - CCVCC
blue - CCCLK
when SIM is inserted:
yellow - CCVCC
blue - CCCLK
OK, so now the oscillograms show us that the CCIN line is not a problem as the module tries to communicate with the SIM card as expected with 1.8V and 3V. But for some reason it fails. It looks strange.
Please verify the SIM card with some other device. Maybe it's been damaged for example while you have been removing it and inserting.
If not you probably should verify the design and real HW for other SIM interface lines and interface. Please take into account the reference design from my previous post and information from the hardware interface description for the module. To avoid possible cross-talk from the CCCLK signal to the CCIO signal be careful that both lines are not placed closely next to each other. A useful approach is using a GND line to shield the CCIO line from the CCCLK line. The total cable length between EHS6 and the pads of the external SIM card holder must not exceed 100mm.
Regards,
Bartłomiej
Hi Bartłomiej.
I'm not trying to solve communication errors between 3G module and SIM card. I'm trying to determine why 3G module doesn't powering up SIM card interface when has SIM card present signal asserted. On our previous design, when CCIN signal is asserted high, SIM card interface is power up and generating clock signal. For now I want to determine why identical 3G module with same firmware, same revision of it doesn't do same thing.
Best regards
Mariusz Szczygiel
Hello Mariusz,
These two things are connected with each other. CCIN line indicates the presence of the SIM tray. When the tray is inserted the module tries to communicate with the SIM card. Firs it tries 1.8V level and it the communication fails it tries 3V. If this also fails the interface is disconnected. And this is happening in your case because of some communication error. It should be the same with your previous project. Please try to insert the empty tray or isolate the SIM pads with the tape for example. You should see the same behavior.
Best regards,
Bartłomiej
Hi Bartłomiej.
I soldered another SIM holder on wires and strip board and connected it directly to module pins. It is working now, next thing I have to figure out what was wrong in first place, probably have to make changes in layout.
Thanks for your help.
Best regards
Mariusz Szczygiel
On the other hand the CCVCC is raised for some time and there is some activity on CCIO line at that time.
According to the CCCLK maybe it's the module maybe some other issue in your hardware. You might need some more HW debugging or a new prototype.
BR,
Bartłomiej