So I am on my way , but I hear a cliking sound befoer my wave file is played. Has anyone got any ideas how I can resolve this. When attaching to a scope i think it is the startup from the DAC itself. Is it possible to enable the Dac at startup, will this help?
I don't know how the software library works but I have a good guess at what the problems is...
The Arduino is powered from positive voltage (there is no negative supply) so in order to reproduce the negative half of the AC audio waveform, the output has to be biased (at half of 3.3V, I assume).
If the bias is suddenly switched on, the DAC output goes from 0V to ~1.65V, you'll get a click. The solution is to set the DAC output at the bias point during start-up, before starting the audio. Then, make sure the bias doesn't get shut-off when audio playback ends. Ideally, you can ramp-up the DAC's output (at around /10th of a second or more) so you don't hear the bias kicking-on when you start-up.
My skill in editing the library is not the best , cany anyone help to setup the dac at the bias point and keep it there?