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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

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
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.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
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
analytical skills graphene is prepared to kill any type viruses .
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
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.
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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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