Interesting stereo audio volume control, easy interface to Picaxe

[fernando_g]

From time to time, I like to browse IC datasheets to view new (to me) devices which would pique my interest. Double bonus if they are Picaxe-able.

As such I would like to share a particular Texas Instruments PGA2311, which should be a bonus for anyone thinking of building a high performance audio chain.
Picaxe controlled, of course. Very simple digital interface.
I am not building anything, not yet. Only wanted to share with this with fellow Forum dwellers.

The only caveat? The price, $11.19 USD. At least from DigiKey.

 

[fernando_g]

For some reason, it doesn't allow me to upload the PDF file.
Thus the link instead:

https://www.ti.com/lit/ds/symlink/pga2311.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1706624685771&ref_url=https%253A%252F%252Fwww.ti.com%252Fgeneral%252Fdocs%252Fsuppproductinfo.tsp%253FdistId%253D10%2526gotoUrl%253Dhttps%253A%252F%252Fwww.ti.com%252Flit%252Fgpn%252Fpga2311

 

[hippy]

Or ... https://www.ti.com/lit/gpn/pga2311

Web servers do present some pretty weird and long links at times. You can see the above hooked on to the end of your link with '/' and ':' encoded as %2F and %25.

It does indeed seem pretty simple to use.

 

[fernando_g]

Indeed, straightforward and simple to use. Direct values, no need to address registers.

Do you think that the HSPI instruction would be suitable, or is it better to bit-bang the values?

 

[inglewoodpete]

Do you think that the HSPI instruction would be suitable, or is it better to bit-bang the values?

I think hSPI would be fine for controlling the PGA2311. I built a 5+1 home theatre controller 17 years ago. I used a 40X2 (with a 14M2 as a dedicated IR receiver/controller). While I didn't use the PGA2311 for volume control, I did use hSPI to control the 6 channel volume. I don't recommend my volume control solution using digital pots due to the clicks in the audio output whenever the volume is changed.

Needless to say, some of the peripheral devices have evolved as technology has developed. There also is room for an improvement in the volume control department! Thanks for the PGA2311 suggestion.

 

[fernando_g]

The difference between a plain vainilla digipot and ones dedicated to audio volume control is that the actual tap changeover occurs at the audio waveform’s zero-crossing, precisely to avoid the clicking.

I also had previously attempted to build an audio attenuator myself, but had also ran in the clicking issue, which remains constant regardless of the actual audio level. At least with the 1990s-era digipots that I used.