Android ymodem over bluetooth in Java

Question

Has anyone successfully implemented ymodem in java to send files over bluetooth (SPP)?

I had a look at this option and wouldn't mind trying to compile some C/C++ code for Android but I do not want to root the tablet, is it really needed? why?

Answer 1

As you pointed out, this is a very good explanation about how to transfer data using ymodem protocol trough Tixy's implementation on Android.

I think that a rooted device is necessary because your application needs low level access to the serial interface/modem in order to transmit data following the ymodem specification (without any high-level incapsulation extra-data) .

Answer 2

You need to root because serial communication in android (and other linux systems) always go over /dev/ttys..

And the permissions for /dev/ttys.. is usually set to rw for root only.

It might be that on some android roms there is access to the devices, but usually that wont be the case.

But if you are able to send raw data over bluetooth (java), you need to modify the ymodem source code that it returns the data pack. Send the returned data pack and you are on a good way.

EDIT

There are some ways to send raw packages:
http://www.intorobotics.com/how-to-develop-simple-bluetooth-android-application-to-control-a-robot-remote/