I've tried the sim card with mobile phone and I've sent and receive sms message. But I didn't sent and receive any sms with example sms sketchs. Have anyone know suitable solution or can i use an API (like twillio) for sending sms ?
I use twillio and thingspeak for two-way messaging. It is fairly involved it make two-way work, but it seems reliable.
I posted an example a while back:
Oops, I can no longer recommend Twilio. I was using the api in demo mode and it was working great. I tried to upgrade to a paid account(very affordable), but they suspended my account and refunded my payment. Apparently, they do not support my "use case".
If they don't want my business, I will go elsewhere.