i use Nokia 30 modem, by the way.
i use these AT commands to send SMS:
> hello world
in my code when sending. when i do it in a loop (to send to multiple recipients), the first recipient receives successfully, but the second recipient does not receive it.
+CMS ERROR: 301
what is wrong here? i googled and error 301 says that SMS funcitonality is currently being used by some other process. However, i checked for response before i send again. so what gives? how to solve this?