Education on Android devices, and question on USB port usage

[DeckelHead]

I am trying to educate myself on the myriad of Android based PSP clones out there and I am hoping this is the place to do it...

I am a professional C# and Java developer so I definitely know my way around programming, but I have never done any Android development. OK, that is the audience, now let me explain the problem:

I actually don't want to develop a game, but I am investigating the use something like the JXD S5110b as the hardware for an application I want to write. Unfortunately the platforms don't give me everything I need, so I also must develop some hardware that contains an alternate communications stream (xBee, for those that are interested) and an RFID reader.

To accomplish all this, I need to have API access to the various parts of the Android based system. I also need to make sure that I can configure the USB port to run in host mode. Clearly I am not trying to download something from a PC but, rather, have the USB act as my interface to my custom hardware.

That sets the stage for what I'm trying to accomplish. Now come the questions, most of which are very basic... Are my needs even feasible for these devices? Clearly games and applications are being written for these Android platforms but I don't know much about how they are downloaded, tested, run through a debugger, etc. Second, I also don't know if the typical API gives you access to the USB so that you can use the device as a host, not just a simple client.

I recognize these questions are pretty basic. Again, I come from the PC business application side of the world. I did lots of embedded programming in my past, but it was in the days before Android existed. Java is no problem but I would love for someone to quickly summarize the basics of how one develops for the modern devices, provide any useful links, alleviate my concerns about the USB port, etc.

Thank you very much in advance. Any help is greatly appreciated.

[thedicemaster]

how USB host works varies between devices.
many older devices can't use it at all, some have a dedicated fullsize USB host port, but most newer devices have a microUSB port that supports host when you connect a USB-OTG cable.
some high-end devices(like samsung galaxy S and note series) can even use their usb port in host and slave mode at the same time when connected to a smart dock.

so with the exception of a few older devices, there's no need to manually enable host.