New to Arduino: where to start from for GSM

Hi guys,
I never used Arduino before, I'm interested in using it on my tooling machines to check the working status, alarms and so on. I need to check just a few digital inputs (like 4-5 signals), setting a couple of digital outputs and receive/send some SMSs.
My questions are:
1- Which kind of hardware do I have to buy? Which Arduino model and which GSM module?
2- Regarding programming: do I have to use AT commands or there's a higher level language library?

Let's start form the basics, thank you for your help. :wink:

I have not used GSM on Arduino but you could maybe start with a GSM shield and an Arduino UNO to plug it into.
We need to know more details about the digital input/output signals you want to use as the Arduino pins can only handle 0-5V so if the voltages are higher (or negative) then you will also need additional hardware to interface.

ATM the input signals I have are 0-24V, positive polarity. 0-5V output signals are fine to me.

I think you can use GPRS SHIELD (seeed studio) and arduino uno , seeed studio gprs shield gives you an overview how to use it using AT commands.

http://www.seeedstudio.com/wiki/GPRS_Shield_V1.0

alekseevic:
ATM the input signals I have are 0-24V, positive polarity. 0-5V output signals are fine to me.

You could use a voltage divider or opto isolator to get the 24V digital signal into the arduino.

@Riva: actually I thought you proposed something "plug & play" for Arduino to manage 0-24V signals... :smiley: I don't like playing with resistors and stuff... Anyway, I'll go for an opto-isolator.

@bhaskar: actually I don't like AT commands, I had a bad experience with them. I hope that there's also a library for normal operations like receiving short messages, extracting sender and text and so on.

Obviously I don't want you to design my device, my problem is that I found a lot of things on the internet about Arduino and a lot of things about GSM modules that I get confused in a while.

alekseevic:
@Riva: actually I thought you proposed something “plug & play” for Arduino to manage 0-24V signals… :smiley: I don’t like playing with resistors and stuff… Anyway, I’ll go for an opto-isolator.

I cannot easily find a opto-isolated input shield so maybe there could be a market for someone like Sparkfun to make one. Or maybe someone local to you could build a protoshield with what you need for a small fee.
Maybe the Ruggeduino would fit your bill better though the pins are not opto isolated.