Question

I wanted to know how to start with a new device addition to android.
Say, I have a new hardware, a barcode scanner and want to add this to my android phone. How do I do this? i mean how do the OEMs go about this? Do they have some kind of tie-up with Google for this proprietary addition?

My understanding/approach is as below:
1. Take the firmware of the new hardware.
2. Interface it with android (here is my doubt,how do I do this?)
3. Write an android application to use the device, say add the costs of all objects scanned by the new h/w. The firmware sends me the barcode. I, in my android app, collect all the codes, match their prices and add them up.
Is this app written in java?

Regards
Aad

Answer 1

Haven’t done this myself. However my understanding is similar to yours–

• if neccessary, write/adapt driver for your HW in Linux kernel
• write userspace library that accesses hw
• extend Android framework to allow programs running in Dalvik VM to interact with the library
• write an app that uses the new features

You could start by grabbing Android framework code from AOSP, and getting familiar with it. The tricky bit would be getting your changes accepted back in official source tree. Otherwise, anyone wanting to use your app, would also need to be running your custom ROM.

For the big picture, here’s Google IO 2008 presentation on Android platform architecture:
http://sites.google.com/site/io/anatomy–physiology-of-an-android

I also think this kind of question is way to general to be answered comletely. I guess you’d get better advice by asking more focused, isolated questions once you start your project.