Seeeduino GPRS APN


I have a Seeeduino GPRS and would like to establish a TCP connection. I get the following error with Seeeduino GPRS_ConnectTCP example code.

GPRS - TCP Connection Test…
Init success, start to upload data…
connect TCP error

I think this could has to do with the APN my provider, which must be set before the internet connection. I tried to set the APN with AT+CSTT in GPRS::connectTCP in gprs.cpp with no success. On wiki there is no info, can somebody help how to this?


Try using the example sketch from Seeduino_GPRS_Master, named SIM800_Serial_Debug example.
Then you could use AT commands directly and get response from Seeduino GPRS.

This will help you to test a lot of parameters from your Seeduino GPRS and your Sim Card.

To check your APN you could type:


Then, if that APN is not the rigth one you can change it by:


If you still having problems maybe is because you need to put more parameters, if you type the at command follow by “=?” it will show you the values that the order could have.

I hope this would help you.

Thank you for the infos.

I couldn’t get the board with the Seeeduino GPRS library but it works with AT commands. I implemented also the connection manually without the library.

I can set the APN as following without problems:

My problem now is that the SIM800H is automatically powering on after 30 seconds later I close the connection. But I will open a new topic with details.

Hi , could you save this setting successfully after cut down the power? I knew news from others that the setting can’t be stored. Could you?