I've recently bought a SIM900A A6 GSM module. Whenever I send a command it gives an error: +CME error 58.
Does anybody know what this means and how to solve it?
Your sim card is probably protected by a PIN. Easiest way to get it working is to put the SIM into a normal phone and remove the PIN protection.
I had the same error. My error was using the incorrect baud rate. Set the baud rate to 115200. Also, ensure that "Both NL & CR" option is selected for new line options. After changing those settings, I had to reboot the A7, and wait for all the status messages to complete before I could send the AT command.
AT
orATZ
?