SMS PDU Mode (again)

Well I have got no where in my quest to send SMS's in PDU mode from the arduino. I have the phone connected to the arduino and can send commands and receive a response etc.

The bit I have trouble with is encoding the PDU. I dont want to send static data, I want to send GPS coordinates and possibly some sensor values.

I have found alot of information on the internet about how PDU works. But I still cant get my head around it.

I have found some examples from Atmel, and some code from other people that is in C, I wonder if it could easily be ported over?

If someone would be able to help me that would be awesome.