My project requires data to be transmitted from a wireless sensor node, via the GPRS network to a datalogging site like Pachube.com
I am using the arduino uno with the seeedstudio sim900 GPRS/GSM module. I have used the sample code found on the wiki. I have got it to sms and make voice calls.
I am having a problem in sending data through to the pachube api.
I understand that what you have is fundamentally OK, it is just that you cannot send data to cosm. I assume you want to send data to cosm for graphic display thereon, in the normal manner.
I don't know anything about GPRS stuff - or software serial - but even the clearly indicated cosm section of your code is incomprehensible, so I believe your problem with cosm is the same as most everybody else's. You are not using the latest libraries - cosm.h and httpclient.h.
You should get these libraries from github and start over again.
I don't suppose cosm knows or cares how the data is sent, so long as it is properly packaged, with the right commands.
You might find this useful http://community.cosm.com/node/1867
It turned out that his main problem was his SIM running out of credit, and maybe his code is kosher by now....