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ADSP-BF706 EZ-KIT test program experiencing bad distortion

Question asked by teague on Oct 6, 2016
Latest reply on Jan 29, 2017 by teague

Hi there,

 

I just recently received an ADSP-BF706 EZ-KIT Mini and have been trying to learn the processor architecture along with the CrossCore Embedded Studio IDE. 


Quick side note: I ordered the 'ADSP-BF706 EZ-KIT MINI' from Digikey, however, the web page I've been referencing is for the 'EVAL-BF706M-EZLITE'. Are these two different boards?

 

I wanted to get a quick start with the board and decided to load one of the test programs that come with evaluation kit. Referencing the 'EVAL-BF706M-EZLITE' web page (http://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/eval-bf706-mini.html#eb-overview), I downloaded the associated software package. This software package included several test programs. I decided to try out the project in the folder 'AudioFilter_Callback_BF706Mini'. I was able to successfully build the project is CCES and was able to run it on the board (the indicator light turned purple). This project takes in an audio signal, applies a filter (no filter, low pass, or high pass), and then outputs the audio via the headphone jack.

 

When I plugged in my aux cord to the 'line in' port and my headphone into the 'hp' port, the audio was incredibly distorted. It sounded as if there was a ton of noise in the signal. However, I was still able to make out the song that I was expecting, it was just a matter of the quality being incredibly terrible. Furthermore, the program uses a pushbutton to toggle between no filter, low pass filter, and high pass filter. Even though the quality was terrible, you could notice that the filters were actually filtering and responding to the push button.

 

So the interesting thing is that the program appeared to be working, it was just a matter of the sound quality being terrible. So I plan on banging my head against the wall more tomorrow, but I just wanted to first verify that I wasn't doing something fundamentally wrong. Since I'm new to both the hardware and IDE, there are so many variables at play. So if anyone has any suggestions as to why the sound quality is terrible, please feel free to suggest it. And like I said, I'm just using the default example programs supplied by Analog Devices, thus I don't see how it could be an issue in the source code. Here are some theories that I have:

 

- I've somehow not initialized the hardware incorrectly. Could I be missing some IDE/drive setting such that the codec isn't being configured correctly?

- I need to remove a jumper somewhere on the board?

- I received a bad board.

- I've forgotten to install something.

- Going back to that note I made earlier about the 'ADSP-BF706 EZ-KIT MINI' vs 'EVAL-BF706M-EZLITE'. Are these two different boards? The 'ADSP-BF706 EZ-KIT MINI' manual links to the 'EVAL-BF706M-EZLITE' webpage so I assumed they were just two different names for the same board. They appear to be identically too.

 

My hardware components include:

 

- ADSP-BF706 EZ-KIT MINI

- Aux cord for sound input from my laptop

- Apple earbuds, and Sony Headphones for the audio out from the board.

 

I appreciate any help!

 

-Teague

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