Hi,

Iam working on wav player, in which i want to play wav file from SD card. With the help of timer i generated interrupts and while interrupts coming PWM's duty cycle is varied. With this logic iam unable to reconstruct the wav file. I think the data from the SD card is not completely read. Can anyone suggest modifications to my code. Please help me. Iam attaching my project here.

In Creator 2 there is integrated the function "Create Workspace Bundle" to be found under the "File" tab. I would suggest to use that to build compressed archives of projects since these can be handled by Creator.

Bob

Some observations -

1) Speech BW is ~ 3.4 Khz, for a POTS line, so you are oversampled by ~ 2X which is

OK.

2) Your PGA is set to low power, which is ~ 3 db down at 1.8 Khz, is that what you want ?

Seems like you want to set that to high power.

3) Your buffer size is 12 characters, yet you burst out 512 samples, maybe I am missing

something here........are you decimating here ?

 4) Your 24 Mhz CPU clock, 4 Mhz SPI clock, = .3 KPBS read rate from SDCARD. Is 300 bytes/

sec a fast enough sample update rate, then decimated by 12 / 512 ? Seems like this is off by

an order or magnitude.

5) PWM out must have a filter, hence a settling time, have you chosen filter components to

meet a settling time and ripple tolerance ? See attached.

Regards, Dana.

There are two buffers.One is globally defined with 512 bytes Size. From the PWMout iam connecting externally a single pole low pass filer.

 How the SD card reading rate becomes 300bytes/sec ?? Can u explain??

My error, I was mis-reading the table, looks like you should be

getting somewhere on the order of 100KBps.

Regards, Dana.

 Then what could be the problem??Still not getting audio :(