AT command, what is it?

What AT command ?

I saw this term in some mobile related discussions. ()

At commands are set of commands which is required for for communication to GSM modules through serial ports.Just we have to give commands through serial it will (GSM module)take action accordingly.

is there any very easy tutorial available?

AT Command is a command set used to control GSM machine, it is very similar with DOS command.
In DOS mode, you key in a DOS command (like DIR, DEL etc), DOS recognize it and execute the command and reply the result...
To control GSM machine, you "key in" AT command, the machine recognize it and execute the command and reply the result...
But the GSM machine don't has keyboard, so the command is injected to the machine thru serial port and the result answer we get from serial port too.

The AT Command set has hundreds of command, please check which completely explain the whole set of Nokia AT Commands.

If you like to get the answer of "What I have to do if I want to...?" questions, read the PDF file I attached.

I don't find any AT command tutorial, but there are SMS tutorial :
:arrow:How to Send SMS Messages from a Computer / PC?
:arrow:How to Receive SMS Messages Using a Computer / PC?

"AT" means "ATtention" :idea: it is a command set used to communicate between the DTE (data terminal equipment) such as computer and the DCE (data communication equipment).

It is used to communicate with the modem and now a day it is also used with a gsm module and the like.

There are available list of at commands in the internet you just have to find the specific one for your equipment. Some commands are the same but others differs from the other.