Hi!
I thought that the TRB did not work since the band (2G,3G,4G) LEDs did flash all the time.
But it looks like it works anyway, I have tested to send a SMS to the TRB and it is output on the terminal.
I only need to issue these commands to make it work.
PDU mode: AT+CMGF=0 (seem to be default 0 anyway)
Select message service: AT+CSMS=1
Immediate SMS delivery: AT+CNMI=2,2
When reading status from TRB I see the below output.
+CPIN: READY
+CGATT: 1
+CEREG: 2,1,“2EF5”,“203AD33”,7
+CREG: 2,1,“2EF5”,“203AD33”,7
So it looks like it just works, I don’t know why really. Maybe you can do some configuration to make the band LEDs showing the real status of the selected band?
I our case the connected legacy device is an older car alarm system which did use an old 2G based mobile “Modem”.
At start it auto configures the mobile modem by sending:
ATE
AT+CPIN?
AT+CSMS=1
AT+CNMI=3,2
This device cannot be configured to not sending the not supported AT+CNMI=3,2 command to the TRB. In a proof of concept solution we are trying to add a serial AT command converter inbetween the TRB and the legacy device. It just converts the command AT+CNMI=3,2 to the supported command AT+CNMI=2,2. This finally works.
But now the sequence is broken in some way, I will make some tests.
It looks like the old device needs to send an acknowledge to the TRB in a short time, command manual says timeout of 300ms, the command is AT+CNMA=0. The old device is doing this but maybe our converter is a bit too slow and the 300ms timeout is passed.
Another problem may be if we converts the line breaks, line feed and carrige return, in a bad way for the PDU message part. The first commands seem to work alright.
I will keep you updated.
Thank you.
