Hello, I know there are other posts about this topic but, I am such a beginner that they are all way over my head. I need an explanation similar to that of a 5 year old. So, I apologize for the repost.
Background
I purchased this shield from ebay (http://goo.gl/ikirM)
Attempting to use it with an UNO R3
I got an AT&T go phone with a 3G sim card
After following the provided wiki (http://www.geeetech.com/wiki/index.php/Arduino_GPRS_Shield) it is clear that something beyond my knowledge is wrong.
I JUST WANT TO SEND A DAMN TEXT.
Does it require a 2G sim card and I have 3G?
RX and TX are pin 7 and 8.
I have the jumpers on the SWserial side.
What is this com tool I keep reading about and why doesnt it exist for mac?
There seems to be a million libraries, which one do I need?
Indicator lights -RED is solid - GREEN flashes 3 times/second.
I know its a drag to go through this with such a beginner but please, I am in need of some help.
New developments have been made. Ive figured out the whole serial communication bit and am now having some connectivity problems. After firing up the shield i get the following read out.
+CFUN: 1
+CPIN: READY
+PACSP: 0
Here are the results to CREG, CBAND and COPS.
AT+CREG?
+CREG: 0,0
OK
AT+CBAND?
+CBAND: GSM850_MODE,ALL_BAND
OK
AT+COPS?
+COPS: 0
OK
When I try to send a text, i get the following.
AT+CMGF=1
OK
AT+CMGS = "+1404****863"
ERROR
Any suggestions to get it working?
Hi, The GSM shield you have purchased uses a SIM900 chip. This chip only works with 2G SIM's and will not work with the 3G network. I had the same problem myself until I worked this out.
The specs are listed http://www.elecfreaks.com/store/4-frequency-ultra-gsmgprs-module-sim900-p-109.html it reads Compliant to GSM phase 2/2+ as far as I can tell this means that SIM900 only supports 2G networks. I have managed to get my shield which is also based on the SIM900 to work with a 2G SIM but it will not recognise the network with a 3G SIM.
Indicator lights -RED is solid - GREEN flashes 3 times/second.
The Green led will be the Network status when it is connected to the network correctly it should flash only once every 3 seconds.
This application note may be of interest
http://www.otto.co.za/store/dataSheets/product/1be0954814643cba0bebabfc07f09a73.pdf
I have collected some manuals for the SIM900 http://www.rupert.id.au/tutorials/arduino/SIM900/ which may help
If you need a 3G sheild take a look at this http://www.cooking-hacks.com/index.php/3g-gprs-shield-for-arduino-3g-gps.html
Good luck