Simple and Fast audio driver for propeller - 44.1KHz 2 channel 16 bit

aempirei

heres an audio driver that i wrote.

the sample rate playback is adjustable and tested up to 44100 Hz

it takes in 2 channel 16 bit unsigned PCM data

it plays back on 2 adjacent pins

this demo also requires the setup of a SD card

its based on SPIN WAV Player Ver. 1a (Plays only mono WAV at 16ksps) by Raymond Allen


- aempirei

AIM: ambient empire

drazmo

Do you have a sample clip to use? I get lots of static using 16 bit unsigned 44100Hz stereo file.

hippy

Haven't tried it but it looks interesting. Looking at your PASM DAC code ...

        rdword val, ptr         ' get new channel 1 frequency
        wrword zero, ptr

        shl val, #13
        add val, nominal  

        mov frqa, val

        add ptr, #2             ' increment to channel 2

        rdword val, ptr         ' get new channel 2 frequence
        wrword zero, ptr

        shl val, #13
        add val, nominal  

        mov frqb, val

Although minor points and may not affect or improve operation here, consecutive hub accesses aren't speed efficient, it's better to interleave instructions between them when you can, updating FRQA and FRQB simultaneously would be preferable from a purist viewpoint.

Something like ..

        rdword vala, ptr         ' get new channel 1 frequency
 
        shl vala, #13
        add vala, nominal  

        wrword zero, ptr

        add ptr, #2             ' increment to channel 2

        rdword valb, ptr         ' get new channel 2 frequence
 
        shl valb, #13
        add valb, nominal  

        wrword zero, ptr

        mov frqa, vala
        mov frqb, valb

Also ... Is zero the best value to write to word[noparse][[/noparse]ptr] ? Can that not be a valid data item ?

Post Edited (hippy) : 4/8/2008 4:03:14 PM GMT