Cannot get SMS receive notifications with EHS5-E, rev 03.001 | Telit Cinterion IoT Developer Community
May 3, 2016 - 10:22pm, 3519 views
Hi
I am trying to use the modem with a Raspberry Pi3 in order to start the pppd ****** on RPi when an SMS is received. The Ring0 line on the modem is linked with a wire with GPIO4 on RPi. Everything seems to work fine and I am getting an electrical signal when an SMS is received, but the problem is that not all SMSs I am sending to the modem seem to be received. The way the modem works is quite random, sometimes the SMSs are received, but in some other cases no SMS is received. My smartphone, using the same SIM card, always receives the SMSs, so I suspect that the problem is with the modem, not with the mobile network provider.
Here are the sequence of commands used to prepare the modem for SMS reception:
- AT //check if modem is present
- ATA&F //reset to factory settings
- AT+CMGF=1 //configure SMS format to text
- AT+CMGD=0,4 //delete all SMS messages from preferred message storage
- AT^SCFG=\"URC/Ringline\",\"asc0\" //trigger RING0 line upon receiving a URC
- AT+CSQ //check BER and RSSI
after this command I am waiting to receive an interrupt when Ring0 is triggered by SMS reception.
Do you have an ideea why the SMSs are not always received by the modem ?
thanks
Bogdan
Hello,
The messages are transferred to the message service centre and from there to the recipient. So it depends on the network when the messages are sent or resent. The first thing I can think of is that if you are doing tests you probably switches the module on and off from time to time. I think that this might be causing some issues and delays in messages reception especially that during such tests you probably don't do any software shutdown but just switches the power off so that the module does not have a chance to do network deregistration. Might this be the case here?
I can't see that you configure SMS notifications with AT+CNMI.
Regards,
Bartłomiej
Hi
Thanks for your reply, indeed I swtich the module on and off, but this happens after several hours. AT+CNMI=1,1 is used to receive notifications on the USB port, while the goal here is to use RING0 line in order to let the modem enter into an idle state.
regards
Bogdan
Hello,
And how about the antenna and network quality? And have you tried to trace these messages somehow to check weather they come later don't come at all or come but are not signalled. Is it possible that the storage is full after some hours or are the messages deleted when received?
Regards,
Bartłomiej
Hi
RSSI is good, I get with "AT+CSQ" a value of 8. The messages some***** arrive later or not at all. I have thought about the storage, not sure how may messages can be stored, but now I use "AT+CMGD=0,4" in order to delete all messages after a message is received and read with "AT+CMGL". For the moment I have decided to follow your advice and let the modem connected for long period of *****. This evening for example, immediatelly after I have connected the modem I have been able to receive SMSs.
regards
Bogdan
Hello,
So that could have been the case. You can configure the SMS storage with AT+CPMS command. By default there is SIM storage used.
Regards,
Bartłomiej