Setup test environment as shown in diagram prior, used an MP3 player as source to Line input and amplified stereo speakers we could hear our modified audio when program loaded and running. Reading switches 1-4 as a binary mode selection allowed easy change of AV application operational mode during testing and operation. Early tests were verifying could read both channels and mute any combination presented to line output jack. Verified we still got output when either delay or echo modes set active. Testing modes greater than 7 where activating the LP, BP, and HP filters bought challenges to learn why there was no output.

          When changing from prebuilt COF sample to ones made in MatLab, experienced no output. This was fixed over time. The GEL sliders are also very beneficial way to vary operational parameters. The Gel sliders used most were the gain_L, gain_M, and gain_H to cause changes to audio output by frequency groups.

          This project implementation taught some first hands-on of the challenges of taking a concept implementation and problem solve short comings. The concept depicted in diagram seemed easy to achieve in some ways. Class labs and text examples were valuable to define this project in a shorter amount of time. The use of nearly all lab assignments and more combined into one product required thought to regroup each sub task so when assembled, each module did not adversely affect other modules. The most challenging problem to solve was not the design implementation but not expecting the variable type changed from MatLab process. The example files were included, so the fact that the prior COF files contained arrays of integers, the new 48 KHz FIR COF files containing floats took a few lab runs before the awareness the code was not the issue but the float/integer type change. Answer was simple; however most helpers said fault was in code hence spent most debug time there. The overall learning experience of hands on implementing each of these modules and being empowered to problem solve our issues, was priceless to the participants of the project.

References

ECE 671 text book Digital signal processing and applications with C6713 and C6714 DSK by Rulph Chassaing

http://www.comlab.uni-kassel.de/cms/fileadmin/Diplom/ProjectKhan.pdf
http://ethesis.nitrkl.ac.in/71/1/10407030.pdf

© 2011 Copyright Maurice Farah. All rights reserved.