In "aek-AUD-C1D9031" - AVAS project the NOISE is high when I use PIT Timer Interrupt.

[shiva_shankar_e]

hi community,

                      I am using the "Avas Compact - Test Application" example code which is provided in the AUTODEVKIT.  I had extended that example code with PIT (the frequency is 1sec). after adding the PIT the WAV files are playing with horrible noise.

 can anyone explain what is the ISSUE.

 Hear i am using  4ohm 5watts  speaker.

regards

shiva

[Max VIZZINI]

hi,

To keep the sound playing in a proper way, you need to keep the playback frequency of 44kHz, as used in this case.

If you interrupt the process with timers and interrupt routines, the playback frequency will be invalidated because not enough digital samples will arrive to the audio amps in time and, consequently, the sound will become noise.

Best Regards,

AutoDevKit Team

[shiva_shankar_e]

hi, 

  1) hear, i had use only one PIT (with 1 sec). apart from that i am not using any other timers or interrupt routines. 

                       hear i had used [4ohm 5watt] speaker. (is there any issue with the speaker).

 2) is there any alternative to eliminate the NOISE.

[Max VIZZINI]

Hi,

1. If you are using a PIT then there is a interrupt routine that gets executed when the timer elapses. If not, why are you using a PIT? What else is the purpose?

2. NOISE is a generic word. If the sound is saturating than it could be an issue with the speaker, but if the noise is with sound interruption, long sounds, beep sounds then it is a playback issue of not keeping the 44kHZ frequency.

Best Regards,

AutoDevKit