I am using the following quickstart guide: https://www.ayomaonline.com/programming/quickstart-sim800-sim800l-with-arduino
I have tried different sim cards (confirming that they work by testing them in a mobile phone) but I cannot get them to register on the SIM800 module.
This is the module that I am using: https://www.aliexpress.com/item/SIM800L-V2-0-5V-Wireless-GSM-GPRS-MODULE-Quad-Band-W-Antenna-Cable-Cap/32877115526.html
The following are the AT commands and outputs:
AT+COPS=?
+COPS: (3,"VODAFONE","voda NZ","53001"),,(0-4),(0-2)
OK
AT+CFUN?
+CFUN: 1
OK
AT+CREG?
+CREG: 0,0
OK
I have checked power supply and that the SIM is plugged in correctly. Any other ideas?