I'm programming my Arduino Nano so it can send data via a SIM900 module.
For setting up the module I do the following:
ATC OK: AT
OK
ATC OK: AT+IPR=9600
OK
ATC OK: AT+CMEE=2
OK
ATC: AT+COPS=? //this takes a lot of time
ATC OK: +COPS: (1,"E-Plus","E-Plus","26203"),(1,"Vodafone.de","no name","26202"),(1,"T-Mobile D","TMO D","26201"),(2,"o2 - de","o2 - de","26207"),,(0,1,4),(0,1,2) OK
ATC OK: AT+CPIN?
+CPIN: SIM PIN OK
ATC OK: AT+CPIN="****" //censored SIM-Number
OK
ATC OK: AT+CPIN?
+CPIN: READY OK +PACSP: 1 +CREG: 2
ATC ERROR: +CREG: 1 ������ RDY +CREG: 2 +CREG: 0 +CFUN: 1
ATC OK: AT+CREG?
+CREG: 1,0 OK
Setup finished
So I wait till my module gets the networks, and then I set the PIN-Number so my SimCard gets unlocked.
The problem now is, that I check the registration status with AT+CREG? which is always +CREG: 1,0 which means.
The meaning of this is (from documentation):
+CREG y,x
y = 1: Enable network registration unsolicited result code
x = 0: Not registered, MT is not currently searching a new
operator to register to
Why doesn't it search for a network?
What I already discovered is, that the PIN-Number some how get lost...
So after a few seconds AT+CPIN? returns SIM PIN which means, that the PIN needs to be entered again. How can that happen?
I already tried to completely unlock my SIM-Card. But that didn't work. I think that the Sim-Card cannot be unlocked.
I also tried the following:
ATC OK: AT+COPS?
+COPS: 0 OK
ATC OK: AT+CREG?
+CREG: 1,0 OK
For selecting an operator I already tried the following commands
AT+COPS=1,"o2 - de",4,"o2 - de" // manual-/auto-select
AT+COPS=1,"o2 - de",0,"o2 - de" // auto-select with operator (optional)
AT+COPS=1,,0 // auto-select without operator
Do you have any ideas?
