<< Chapter < Page Chapter >> Page >

Use the Project Explorer (left pane in Eclipse) to open the different files and familiarize yourself with each component.

Building the project

Building the project actually consists of first building your Native C code as a library using ndk-build , and then building the Java code, which is responsible for loading the C library and executing your functions.

For this lab project, the build process in Eclipse has already been configured to build everything automatically, and so building your project is as simple as clicking Project>Build Project .

You may want to uncheck Build Automatically , and then build by first Clean ing the project and checking the "Immediately start build" option.

C syntax support

Open .\jni\process.c in the Eclipse editor. This file contains the processing function, which is where you will implement your signal processing. If you see notifications for syntax errors, then in the Project Explorer , right-click on the project name and go to Project Properties>C/C++ General>Paths and Symbols and add the following three files into the Include directories for GNU C : C:\NvPack\android-ndk-r8\platforms\android-9\arch-arm\usr\include C:\NvPack\android-ndk-r8\sources\cxx-stl\gnu-libstdc++\includeC:\NvPack\android-ndk-r8\sources\cxx-stl\gnu-libstdc++\libs\armeabi-v7a\include

Part 2: a development environment for signal-processing applications

Function declarations in java and c

In the Lab4Activity Java class, the following function declaration is made:

public static native void process(ShortBuffer inbuf, DoubleBuffer outbuf, int N);

Where is the Lab4Activity class defined?

According to the "Understanding the Android Project Structure" section in Part 1, you can find it in Lab4Activity.java in a sub-directory of .\src\

Here, the native keyword states that process() is a Native C function. The first argument points to the Java-equivalent of a short[N] array, which holds a block of the 16-bit audio data. The second argument points to the Java-equivalent of a double[N] array, which you have to fill with data to visualize on-screen.

In process.c , the C-equivalent function declaration for process() , along with pointers to the input and output buffers have already been written for you. Appropriate header files have also been included, including the FFTW library, a popular C library for implementing the FFT.

Debugging in java

To introduce the Java debugging environment, you will verify that the mechanism for using test vectors is working correctly. First, in the Lab4Activity class definition, set the variable FILE_INPUT to true . Set a breakpoint on the line where process() is called.

Click Run>Debug , and debug as an Android Application . The project will automatically rebuild if out-of-date, and should switch to the Debug Perspective . The application will automatically run and be halted at the set breakpoint.

Click Window>Show View>Expressions and add the following expression: sb.get(0) , which returns the first value in the buffer. Verify that the value is correct by comparing to the values in the lookup table defined in LOOKUP.java . Repeat this for other values in the table to convince yourself that the test vector values were copied correctly.

The Android Reference guide contains detailed information about the classes you will encounter in Java (e.g., the ShortBuffer class).

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Ece 420 fall 2013. OpenStax CNX. Sep 26, 2013 Download for free at http://cnx.org/content/col11560/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Ece 420 fall 2013' conversation and receive update notifications?

Ask