1. ultrasound digital pen
Industrial Project (236504)
Taking notes with
ultrasound digital pen
Students: Yury Nahshan, Shay Dahan
Supervisor: Noam Dagan

2. Introduction
Current Android tablets market lacks of platforms with stylus input support. This due to absence of OS level stylus support over Android. But Android 4.0 Ice Cream Sandwich includes native support for Smartphones and tablets with a digital stylus. Also Qualcomm came out with new ultrasonic pen that's able to transcribe writing on paper directly into one's phone, tablet or laptop. This brings new horizons for future android applications market.

3. Goals
Create android application for Tablet platform to allow users to take notes on top of PDF presentation.
Application should support touch and stylus input methods, when stylus input mode is main target to demonstrate capabilities of Ultrasonic pen.
Implement mechanisms to open pdf files, save presentation with notes to special file format, load it into application, and make application more usable by good looking UI features.

4. Environment Jet Brains Intellij Idea was used as developing IDE.
All project is written in Java as main language for android development.
Android SDK was used to run and debug application, also it was tested on real device.
QUALCOMM's Snapdragon S4 Liquid tablet was used to run and test the application at final stage.

5. Methodology
Application is created using Android 4.0 OS framework and consists of several activities.
Main activity responsible for displaying all the objects user is interacting with including PDF presentation, notes and toolbar. Every note is represented by note object which allows to manipulate with notes like separate objects, store them to file with respect to color, location and size.

6. Methodology
Opening PDFs – Implemented by using open source Android Pdf Viewer (APV) which based on native C library called MuPDF. We used only the relevant parts of APV to convert pdf file into bitmaps and display it on the screen.
Saving and loading – save/load mechanism implemented using JSON serialization method(JavaScript Object Notation) and GSON open source library.
Integration with ultrasonic pen which implements existing stylus events.

7. Achievements
Fully functional application for taking notes in short time period.
Non trivial integration with external PDF library.
Integration with Pen API to work correctly with ultrasonic pen (on and off screen).

8. Conclusions
Google built very powerful framework for developers which allows fast and comfortable application development.
Every process in Android OS is limited by 24Mb of memory which is enough for most applications but sometimes can complicate development process.