Purely for my own edification; is it possible to use the I2S DAC as a regular analogue output or would that require commands that are not supported?

Hi Phenix,

Please understand that audio DAC's don't necessarily have good DC performance.

The last audio DAC that could be used for DC was the TDA1540/TDA1541 from Philips (from the first generation CD players).

So if you plan to use I2S DAC's for a servo loop...forget it.

Volhout

  Volhout said  

So if you plan to use I2S DAC's for a servo loop...forget it. Volhout

The analogue input of industrial servo-drives, only resolves to 12-bit so there would be no benefit.

I don't see DC performance being an issue, though. Observing the analog motor command from a 1KHz PID looks like horrendous noise  

Phenix,

DC drift is not always specifically specified, but look at below datasheet.

Typical 16 bit I2S DAC UDA1334



DC accuracy is +/-10% (0.5V+/-50mV), relates to 3.5bits DC DAC. If that is sufficient, then you can use it as a DAC in your loop.
That is why it is normal to AC-couple AUDIO DAC outputs. DC drifts all over the place.

Volhout

Thanks Harm. I have no intention of doing this. I was searching through the PicoMite manual for PIO stuff and, as always, I was sidetracked