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This process has shown you how to set breakpoints and single-step through Java code.

What happens if you try to step into the process() function?

The debugger will step over the function because it is written in C.

Debugging in c

Debugging in C is done using ndk-gdb , which is supported in Eclipse. To do this, first terminate any existing debug session and then on the Android device, exit the current application by hitting the home button.

To configure GDB, switch back to the C/C++ Perspective and do the following:

  1. Click Run>Debug Configurations...
  2. Select Android NDK Application and press the New icon, and rename the configuration to Lab4 (1) .
  3. On the Android tab:
    1. Under Project , hit Browse... and select the current project.
    2. Under Misc. , select Attach to the running application .
  4. On the Debugger tab:
    1. Select the GDBserver Settings tab.
    2. Use the APK bundled GDBserver.
  5. Apply the settings and Close .

In order to launch GDB, you must first run the application on the Android device, and then attach GDB to the running application. To do this:

  1. Set a breakpoint inside the for loop in process.c .
  2. Click Run>Run . You should see the application launch on the Android device, ignoring any Java breakpoints that you have set.
  3. After the application starts, click Run>Debug As...>Android NDK Application . The Debug Perspective should launch again, but this time with gdbserver debugger . The processor will halt at the set C breakpoint.
If Android NDK Application does not show up, make sure that Lab 4 is highlighted in the Project Explorer before trying to launch the debugger.

In the Expressions window, the sb.get(0) (which is a Java method) will have generated an error as we are now debugging in C. Verify that inBuf has the same values as the test vector look-up table by adding inBuf[0] to the list of expressions; check several different array indices.

Exporting variables to a file

A useful feature that is fully supported in CCS is the ability to export processor memory to a file, which can then be imported into MATLAB for further analysis. To enable this feature in Eclipse, the lab machines have the eVars plugin installed. As an example, to export the inBuf array to file:

  1. In the Debug Perspective , go to Window>Show View>Variables .
  2. Right-click on the inBuf pointer and select Display as Array .
  3. Click the Expand Variables icon multiple times until the entire array has been expanded.
  4. Once the array is fully expanded, click on the Export Variables icon, and save to a txt file.
  5. Use evars2array.m to read in the text file into a MATLAB vector.

In the next lab, we will see how to create and write to a file on the Android device, and use adb to download this file to the host machine, directly from MATLAB.

Part 3: a spectrogram algorithm in matlab

As an initial step towards implementing the spectrogram in Android, you will first implement it in MATLAB. [link] shows the components that your spectrogram algorithm should have; the ability to overlap, while important, will be left for extra credit, and is therefore optional.

Spectrogram components

Overlap->Window->Zero-pad->FFT->Magnitude squared->log()

If you need to see an existing implementation, type open spectrogram in the MATLAB prompt. This will open the spectrogram function you used in the Prelab.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Ece 420 fall 2013. OpenStax CNX. Sep 26, 2013 Download for free at http://cnx.org/content/col11560/1.3
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