This is unlikely UNLESS the iPod is jailborkened.

There is no hardware access given to app developers. I know because I need Bluetooth SPP and even that is not available.

Here's what does work. Some wifi dongle from serialio.com and then some small micro and battery and whatever else is needed there. It's wifi so it's possible. But the price may cause those that are doing this as a hobby to not do this.
Bob