We are working on the same thing
I grabbed my old Ipaq 3650 after flying today and got about as far as you did. Here's a short vid.
Pocket PC Programmer
I used eVB as well. I needed to use a level shifter to get the 5v signal up to standard 12v rs-232 so the Ipaq would read the signal. Did you run into this problem? My electronics knowledge is pretty rusty and I had a level shifter sitting around but I hope there is a better way to get around this.
I used the eVB vertical and horizontal scroll bars for stick positions. I have the inputlen and input thresold set to 100 bytes and that seems to give near instant and very smooth response between the tx and the Ipaq.
I have to say thanks, you definitely provided the catalyst with the protocol and all. I'm going to finish up the programming parts this week as well as move the level shifter into the tx case. I installed a 2200 lipo in the tx as well and will be adding new bettery level monitor for it. Now if I can just figure out a way to mount the Ipaq to the case
Oh and since the programming parameters only use 69 bytes, I can use the remaning 20mb of memory in my Ipaq to store over 200,000 models
I love this radio, it will end up being exactly the way I want when I'm done
eVB source I have done so far is here: Source
Once I have a ready version I'll post a full build report and installer link. But, you'll need to make your own cable and possibly a level shifter. Maybe keepitsimple will have some better ideas.
This site has given me a great deal, it's nice to be able to give something back.