Students

[JÞB]

The idea of class projects is to learn applications of, and how to apply, the theorys discussed in the lecture hall.  The three nearly identical and  nearly simultaneous posts related to an ecg 60hz notch filter, suggest the ecg notch filter is homework.  By now you should have the fundamental math knowledge to solve the problem in several simple ways.  (like using the help search to find a FIR filter and the library to learn about signal processing techniques)

That being said- Try at least to find a NOVEL approach to constructing a 60Hz brick wall notch filter.  You can save a lot of memory and trade it off for processing power needs (cheap trade these days) by sampling your data at 270 hz and UNDERSAMPLING your data simulaneously at both 40 and 45 Hz.  The 60 Hz peaks will fold to 15 and 20 Hz respectively but have the same phase component.  Compare the folded magnitudes and phases of the ffts of the acquisitions and you know exactly what to subtract from the 270 hz sample FFT. Hint: you can tell the folded (ambugeous) magnitudes from the unfolded magnitudes by subtraction of the FFTs of the waveforms.  

IFFT(270)= IFFT(FFT270-FFT(IFFT(FFT40-FFT45) = Brick wall filter for 60Hz and harmonics.

For other application of this technique search radial velocity unfolding in Doppler weather radars or Dr. Richard V. Paserelli MIT.

[BlueTwo]

I spent 9 years teaching at a University (not LabVIEW 😉 ) and Jeff is right, applying your own intellect is what it is about. Ripping stuff off the interweb will not be getting you very far... Education is an opportunity to learn, cutting and pasting is wasting that opportunity.

Sure, you can play the game, pull the wool, get the ticks in the boxes, but at the end of it will you really be very well equipped to head out in to the work place? To differentiate yourself from your cohort? 

At degree level and beyond, any Prof., lecturer and employer worth their salt will be looking for evidence of problem solving, exploration and free thought, as well as fluency with the tools (and after all LabVIEW is just a tool). 

So sure, use the resources available to you, but do so intelligently, make sure you get some educational benefit from the process. 

Message Edited by BlueTwo on 07-03-2009 04:32 AM