Difference between revisions of "Audio with PWM"

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It is possible to generate sound with the APF9328 without any sound chip, just by using the PWM output and the i.MXL possibilities:
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It is possible to generate sound with the APFxxx boards without any sound chip, just by using the PWM output and the i.MX possibilities:
  
 
[[Image:AudioWithPWM.png]]
 
[[Image:AudioWithPWM.png]]
  
 
==Quality==
 
==Quality==
Achieved sound quality is low (8bits @ 8, 16 or 32KHz) but very sufficient to reproduce voice or small sounds.
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Sound quality produced is low (8bits @ 8, 16 or 32KHz) but very sufficient to reproduce voice or small sounds.
 
PWM activation/deactivation is generating "clac" each time you play a sound (for the moment) but using some electronic filters or playing "blank noise" could solve the problem.
 
PWM activation/deactivation is generating "clac" each time you play a sound (for the moment) but using some electronic filters or playing "blank noise" could solve the problem.
  
==Links==
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==Linux driver==
 
* [[PWM|Armadeus PWM driver]]
 
* [[PWM|Armadeus PWM driver]]
* http://www.fpga4fun.com/PWM_DAC.html
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==Links==
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* http://www.fpga4fun.com/PWM_DAC.html FPGA PWM IP
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[[Category:Audio]]

Latest revision as of 13:57, 15 August 2010

It is possible to generate sound with the APFxxx boards without any sound chip, just by using the PWM output and the i.MX possibilities:

AudioWithPWM.png

Quality

Sound quality produced is low (8bits @ 8, 16 or 32KHz) but very sufficient to reproduce voice or small sounds. PWM activation/deactivation is generating "clac" each time you play a sound (for the moment) but using some electronic filters or playing "blank noise" could solve the problem.

Linux driver

Links