Can custom USB devices be made to work with an Apple iPad?

I make LED glow toys for a living and am in the process of porting the windows d开发者_StackOverflow社区rivers over to MAC and Linux O/S's. I'm making some headway on the MAC front (I'm using libusb) but now I'm wondering if it could be made to work on an Apple iPad as well?

I've seen some reports of people getting other devices working (keyboards, usb flash drives etc.) which gives me some hope but has anyone tried anything like this?