Uno and SIM900 card

Official Hardware Retired GSM Shield
1

I am having problems getting anything out of the SIM900 card (http://www.ebay.co.uk/itm/271723614024?_trksid=p2057872.m2749.l2649&var=570561475114&ssPageName=STRK%3AMEBIDX%3AIT

and the arduino uno.

On firing up the Boards, the power light comes on when the power button is pressed, the led for "Net" flashes quickly, after a few seconds this changes to quick on, long off. I am assuming that this means the SIM900 is connected to Vodafone.
If I send a text from my phone to the SIM900 the power led dims for a very short while, If I make a voice call the power led dims the length of time I hold the line open, as soon as I clear the lines the power led comes back on. Again I assume that it is receiving both.

Although there is a socket for a battery I don't have one until next week, is it essential to be installed?

I have tried numerous sketches from the web over the past few days but got nowhere.

My eventual aim is to be able to control 4 outputs from the Arduino and report back to my mobile that this has happened.

This is a new side of Arduino for me and I must eat humble pie and say I am completely out of my depth.
Can anyone help me please, perhaps you know of a sketch that will work with this configuration?

2

No, you don't need a battery, that's just for the clock.

Take a look at www.simpasture.com/26020.html first, which deals with common problems, and then the page in my signature.

3

Thank you dannable, I have learnt more from your reply than 2 -3 days of searching the web. If I may be so bold can I come back to you if I fall off the wall?
Your sketch work fine and very instructive.

4

Of course, if I can help I will.

5

Thanks entirely to dannable and his subsequent PM I now have an all singing, all dancing sketch. I can sms my arduino, it won't accept other numbers, it does as it's told and even sms's me back to say it's done so.

It is nice to know there are such helpful people about.