FFT setup in Diadem -- joint time frequency

[jtw131]

Hi Brad,

I haven't had a chance to look at your latest cut yet, but I did want to answer your questions in the meantime...  For this application we can always count on the beginning of the files to be named the same thing -- the remainder of the file name is a three digit count.  For example:

AccelX001.csv

AccelY001.csv

AccelZ001.csv

Audio001.csv

I am attaching a zip file with all of these files for the example dataset we have been using.  In the next few days I should have a larger, more interesting dataset to examine. 

If we can have VIEW maintain cursor position between sheets that would be most excellent.  I am also on board with your zoom idea.  This will especially be important when we have 10 hours of data to examine instead of 30 minutes. 

I'm glad I got lucky that this was an area of interest for you and NI.  It would be fine with me to turn the application into a User Solution and I can provide more details on the project -- we should do that over email.

Thanks

Jeff

[jtw131]

Brad,

I checked out in detail your latest incarnation, and it is looking very good.  The FFT and raw data are now lining up perfectly, and bad timestamps are discarded.

I just got data back from the first field test and it has been cool to have the DIADem display ready to go to examine the data (attached part of it to this message in TDM format),  A couple other minor things I notice:

-- The audio sampling rate is 30KHZ, but I only see FFT data up to 2KHZ.  

-- Some more nice to have ideas -- It would be great to have a text box somewhere that shows the current time stamp being viewed.  If we had this we could lose the time axis labels on a lot of the plots and save some real estate.  If we can also show the lat/long coords in this box without too much trouble that would be good too.

Thanks again brad for your help! 

Regards

Jeff

[Brad_Turpin]

Hi Jeff,

Your last couple of requests are also things we can hammer out over time.  The lower and upper limits for the FFTs are set in the JTFA.vbs script, so you can extend the the 20kHz limit if that is too restrictive for the audio data.  I added those limits to reduce the amount of  boring blue frequency space and minimize the need to zoom.

I ran into a busy stretch this past week, but hopefully I'll be able to get back to helping you with this pretty soon.

Brad Turpin

DIAdem Product Support Engineer
National Instruments

[jtw131]

Thanks Brad, I will try extending the limit and see if that solves the problem.  I appreciate all your help and I am sensitive to the fact that you have other high priority committments. 

I will, however, give you something else to chew on in your "free time".   It turns out the highest priority problem I need to solve right now is being able to color code part of the Lat/Long plot depending on the amplitude or frequency content of the acquired data.   Any suggestions on the best approach to implement this?   I am thinking another script that steps through the data and creates a list of times when the data meets the threshold rule for amplitude and/or frequency.  I then find these times in the NMEA group and make another list of the corresponding lat/long coordinates.  In my system all data acquisition is triggered off the GPS packet, so the times will exactly line up (no need to search in between time limits because there are not two separate clocks, if you follow me).  I will take the list of lat/long coordinates and plot it on top of the entire lat/long route, using a different color or marker to make it stand out.  What do you think?

Thanks

Jeff

[Brad_Turpin]

Hi Jeff,

Your plan for adding conditional coloring to the Latitude/Longitude plot is the best approach I can think of.  I would solve that the same way.  I would, however, just add that code onto the end of the JTFA.vbs script we already have, once it's developed and debugged.

I haven't forgotten you, but I also haven't done anything new,

Brad Turpin

DIAdem Product Support Engineer
National Instruments

[DRock]

Hey Jeff -

I'd love to take you up on your offer to turn this example into a User Solution for our website - we're always trying to evangelize the cool successes that our customers are having with our products. Plus, it gives me an opportunity to talk about Brad's constant willingness to go above-and-beyond the normal call of duty.  I agree that the best mechanism for continuing this is via email.

At your convenience, would you mind contacting me via email so that I can learn more?

I look forward to hearing from you.