Hi!
You can check how I did this in my Lego Mindstorms NXT interface, pre-beta version:
That's really cool! I hope you can upload this to hackage soon.
I do not think it is ready yet. It is working but it is missing extensive testing (making some bigger programs in practice, to see how it behaves and to see if the API is sane) and of course documentation (how to use it, examples, tutorials ...). I will continue with this project in a few months. (The main reason is that I do not have any experience with Hackage and Cabal nor I have time now for this. But if anybody wants to help ...) I am using it in my AI robot research project where I am using Lego Mindstorms NXT unit and communicating with it over Bluetooth. And the AI is made in Haskell. :-) Mitar