EHS6 : simtray = 0 but SIM & GPRS data exchanged | Telit Cinterion IoT Developer Community
August 31, 2016 - 2:40pm, 3751 views
I'm using an EHS6 on home-made hardware and I'm facing an issue.
Our java application on EHS6 is active, GPRS 2G-3G Data are exchanged.
(at^sled=2 give 3900ms blinking after startup)
But the SIM card is seen as not detected and our java application reboot because of this "undetection" even if data are fully transmitted.
at-sind? give simtray,0,0 but we have GPRS DATA !!
at^cpin give ok !
CCIN track is low, checked and all connection from EHS6 to SIM card connector are checked and compare with previous design on AC75/TC65i boad.
Is there any configuration I need to do in AT^SCFG or something else ?
What could explain this unlogical situation ?
If CCIN line is low there's some problem with your hardware, SIM card holder or it's connections. Maybe the supply for the CCIN switch is just not connected. Is the line always low or does it change.
However the SIM interface should also work even if you leave the line unconnected. According to hardware description of CCIN: "Input on the baseband processor for detecting a SIM card tray in the holder. If the SIM is removed during operation the SIM interface is shut down immediately to prevent destruction of the SIM. The CCIN signal is by default low and will change to high level if a SIM card is inserted. The CCIN signal is mandatory for applications that allow the user to remove the SIM card during operation."
So according to the above description the SIM interface will be disconnected only when the CCIN line changes from high to low state, if it is always low the SIM interface will work.
I read again the datasheet and found this information.
Surprise by my card holder behaviour. I'm going further.
It works by putting ("dirty ****") direct 1V8 on CCIN pin on EHS6.
Thx again Bartlomiej !
I have now the complete story...
On AC75, and previous Modem, CCIN is low when SIM Card is connected.
On EHS6, CCIN has to be high the show connected SIM...
What a surprise...
Oh, interesting... it really is like you have described :)
can i please know how you did it ? I have some issues wiring the sim connector to the module in my schematic. If possible leave the datasheet in comment.
Please write more about your problem. Do you have a hardware interface description document for your module or example schematics?