STM32F4 Discovery Audio

[modcan]

Posted on May 23, 2012 at 09:20

Hi,

I am trying to use the audio from flash example and modify it with my ultimate goal being to have it play through a short buffer of say 16 sample that are updated with processed wave data. I don't want to play through a long table as it is now. So far I can't figure out how the change the sample size. Currently it is defined as 990000 but if I change it to anything less than 200000 it crashes or at least acts unpredictably. The code is confusing because it mentions in the comments that the wave is less than the buffer size so no need to worry about call backs but isn't the buffer DMA MAX 0xffff. Any guidance about how to reduce the length of the table playback loop would be much appreciated. I have tried replacing the table with 65536 step sine wave  table but it doesn't play. Thanks

[raffael]

Posted on May 23, 2012 at 10:15

Hello,

Unfortunately I c'ant give you an answer to your questions. I'm planing to implement audio processing and IO on the STM32F4 too... Probably I will have a look at it this weekend. Perhaps I could give you an answer then. Unfortunately the flash example is quite tedious to understand and modify. ...Redefinition of redefinition of #define.... If you get it to work, it would be nice if you could share your code 😉 Best