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DAC Output

Topic last updated 15 May 2012, by Nikolas Karakotas. 2 replies
Nikolas Karakotas
13 May 2012

Hi,

I'm using the wavplayer to play sound from an sdcard. I have this glitch once the first values is outputted from the DAC. For example if DAC_fifo is [0,3000,0,3000] once it outputs the 0 its OK then once it outputs the 3000 it glitches. It then settles. How can I solve this? I dont know if its a hardware or software problem.

Regards, Nick

Kevin Hobbs
14 May 2012

Presumably your sound must be bipolar, so the waveform is centered around mid range of the DAC 512 out of 1024 for a 10 bit dac.

If your starting value is 0 then there is a step change to the mid-range value when you start outputing data. Could you iniatialise the DAC to mid range 1.65V at the beginning of your code and also reset it to that value at the end?

Nikolas Karakotas
15 May 2012

Hi,

Yes this is what I did and the problem has been solved.