TCP connection SIM900



Hello, Im trying to connect my arduino with the cloudmqtt, using shield 3G/SIM900 and mosquito, I follow the steps on the video guide but the messages dont arrive to the cloud.

How can I make the error check for this connection, what does the AT+CIPSTART/CSTT commands returns? how can I check does errors?

Thanks for the help


The SIM900 is 2G module and doesnt support 3G.

Have you set the correct username , password , MQTT host and port number?


Thanks Ravi, that was the problem, we were using a 3G SIM in a network that doesn`t support 2G anymore.

Which shield that supports 3G do you recommend to make the connection between an arduino and cloudmqqt using mosquito.



You can use SIM5320 or SIM5360 shields. Or SIM5300E if you are in Europe.


Ravi I was able to establish the tcp connection, thanks you very mucho for your help.

I have two more questions about the SIM900, that maybe you can help me with.

  1. Does it come with GPS?

  2. About the AT commands, is there a way to read the responses with the arduino so as to take actions which each response?

Thanks again


SIM900 doesnt have GPS. SIM908 and SIM808 have.

Yes you can read responses and collect in buffer and process them, Collect UART data in a buffer byte by byte and process them.