Configuring volume controls and ADAU1761 inputs in SigmaStudio

Discussion created by Sean on Apr 1, 2010
Branched from an earlier discussion

Hello JeradL,

This forum is indeed very helpful and I am greateful for it for sure!

Thanks for not taking my comments personnally.  I just find that engineers typically have a difficult time communicating what they know to those that don't and the help file typifies this more oftne than not.


As to the spicific issues:

1. You are right and I was wrong.  I was thinking of the min/max of the volume control slider is not being specified. As to the values of gain, here is a great example of what I was saying earlier.  There is no link in the gain number discussion to the help file's page on what those numbers mean.  For those of us that have never even heard of a 5.23 format, this would be very benificial.  As well as clarification that the gain discussion is purely voltage and not power.  Also, I am assuming that the -gain is attenuation. The behavior acts like it is still gain but I am guessing there is phase inversion.  I am used to the RF world so the polarity of "gain" more generally refers to gain vs. attentuaion.  Again clarity is what a help file is supposed to be all about.  Very short and succinct definitions can be created and yet contain vast amounts of information if worded correctly.


2.  I have uploaded a project were I cannot get the cascading of modules to work without a "beat freq" being generated.  The cascading I wanted was using a single slider with lets say three algorithms so that the algorithms are seen as sucesssive stages so that I can use only one slider to control all three gain stages simultanously.  This cause a loopback error when in fact there is no loop back to the individual inputs but to the module.  I did start another project from scratch with only multiple volume modules with I/O and nothing else and that worked.


3.  This INPUT issue is still very unclear.  The DSP chip has 6 analog input pins.  After playing with the eval board, it seems that IN0 corresponds to the LEFT channel no matter what "input pins" are connected outside the chip itself and the same for IN1 is the right channel. There is no correspondance to "INPUT" being to an input but to a channel.  This is very different for those of us that are used to uC where "INPUT" refers to an individual pin on the chip.  Am I missing somethin or totally misunderstanding the INPUT module?  This issue is even more confusing when the I put the mouse over the INPUT, there is a PIN assignment as if it is selecting an actual pin of the chip.  If the popup window is suppose to point to a register, then the register name would be benificial.  Please see atttached pic and explain what is being said inside the information window.


Thanks for all the help.