ADAU1761 LD/RDVOL ignored

I wasn't able to see what was wrong from your register dump so I just created a basic example project that should work with your evaluation board.

Use two TRS audio cables to connect DIFF OUT L to IN 1 and connect DIFF OUT R to IN2. The Sine tone generator in SigmaStudio will output on the differential outputs, which then loop back to the inputs. I connected the inputs to two level meters in SigmaStudio (you need to turn them on after you download the project to your eval board). By changing the LDVOL and RDVOL controls in the register window, you should see the levels of the differential inputs going up and down on the level meters.

Thank you Brett,

I tried it on SigmaStudio, and it works, what I don't understand is why changing the register from I2C (I'm using the Linux driver) the volume doesn't change at all.

Matteo

That's strange. I wonder if perhaps there's some kind of address mis-match in the Linux driver version. Can you try using the "Capture Window" in SigmaStudio to see what address is being written when you perform those register writes? Then check to see if it matches what you're seeing when using the Linux driver.

LDVOL should be address 0x400E (decimal 16398)

RDVOL should be address 0x400F (decimal 16399)

In the dump I sent, (offset @0x4000), they evaluate to:

0x400E -> E1

0x400F -> FD

Which seem consistent to me. Who can I contact maybe @ADI to double check it with me?

Thank you in advance,

Matteo

Ok, I finally found what the issue was: the ALC clock was disabled. Register 0x40F9 evaluated to 0x5F, while it should have been 0x7F.

This solves both the ability to control LDVOL/RDVOL (it seems to be a fixed ALC setting more than a PGA setting) and the ALC of course.

Thank you

Thanks for this info, very helpful.

I will "Mark Question as Assumed Answered".

This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

Thank you,
EZ Admin