Noise Cancellation Headphone

vinod lohar

Other Parts Discussed in Thread: TMS320C5515

Dear all,

i am working on noise cancellation headphone in which two microphones are used. One for reference signal which is outside the headphone and one for error signal which is inside the headphone earcup. i have TMS320C5515 eZdsp kit & i am a beginners on that kit.

i want to read two analog inputs at the sampling rate of 40Khz or below so can u tell me the how to set the sampling rate.

is it possible to get ADC interrupt at 40 Khz so within that period i can implement adaptive algorithms and then output send to the DAC.

please help me as soon as possible.

over 14 years ago

0 Brian Willoughby over 14 years ago

Genius 4630 points

If I needed to find the answer to this as quickly as possible, then I would start with the schematic for the eZdsp. On that, you will find the part number for the ADC chip. Download the data sheet for the ADC along with all of the relevant data sheets for the TMS320C5515. All of the information that you need to find your answer can be found in those three sources: The schematic, the ADC documentation, and the C5515 documentation.

Good luck!

0 Peter Chung over 14 years ago

TI__Expert 8065 points

Vinod,

You can get everything about the board from the link below.

http://support.spectrumdigital.com/boards/usbstk5515/reva/

AIC3204 is the codec on the eZdsp board. You may want to review the AIC3204 datasheet (http://focus.ti.com/docs/prod/folders/print/tlv320aic3204.html) or post a question to Audio Converters (http://e2e.ti.com/support/data_converters/audio_converters/f/64.aspx)

Best Regards,

Peter Chung

0 vinod lohar over 14 years ago in reply to Peter Chung

Prodigy 30 points

thanks All,

i solved problems related to the sampling frequency with the help of data sheet.

can anyone tell me ... is it possible to write program which is mixer of C & Assembly code function. if possible then how to send argument value in assembly function and recall it.

Is it possible to multiply two fraction value?? if yes then how to take fraction value from ADC???

if any fraction maths library is available then please send me the link if C5515 support maths library.

0 Peter Chung over 14 years ago in reply to vinod lohar

TI__Expert 8065 points

Vinod,

I am glad that you solved the problem.

Yes, you can mix C code and Assembly code. Please read carefully the complier's guide. It will tell you how. http://focus.ti.com/lit/ug/spru281f/spru281f.pdf

Regards,

Peter Chung

0 MK MK over 14 years ago in reply to Peter Chung

Prodigy 10 points

Hi Vinod,

when reading this, I was getting excited as I had the same application of a noice cancelling headphone in mind. I directly ordered a TMS320C5515 eZdsp kit and would like to ask, whether possible to join?

Best Regards,

Marcel

0 Max Zhegulin over 14 years ago in reply to vinod lohar

Intellectual 420 points

Hi Vinod,

For your DSP algorithm implementation on C55xx Dsplib will be very usefully.

http://focus.ti.com/docs/toolsw/folders/print/sprc100.html

Max

0 vinod lohar over 14 years ago in reply to MK MK

Prodigy 30 points

Hi Marcel,

i started project work now. in eZdsp kit only one stereo input is given so i am using left channel for reference signal and right channel for error signal. till now i have done only ADC-DAC loop back. but now i want to start first FIR filter using assembly language bcz MAC instruction is very helpful.

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Noise Cancellation Headphone