AI-Thinker A6 & AT&T

Hello I have an AI thinker A6 module / board. I put an unlocked sim card in it from an AT&T samsung phone. It is not connected to the network as seen with the AT+CREG 1,13. I do not know what the 13 means. I could not find a chart that went that high. Attached is the com port info.

I need to get past this hurdle before I can send an SMS

I think possible issues could be:

AT&T might not let me move the sim card
AI thinker might only support 2G - I am finding mixed things about this

Any thoughts would be appreciated

Anthony

Com Port.jpg

Anybody using this in the US on a network with no 2G?

Anthony