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      • 270. Re: New reworked driver for Wolfson/Cirrus Logic audio card
        psyj

        Chris,

         

        A full reply is probably best, for others that may be reading (oh I flatter myself).  The original thread is correct,  you could cut the trace,  but equally you could remove pin 12 from the 40 pin header. Or equally remove R39. All three are electrically identical. Removal of R39 is the most elegant in my opinion, but carries risks in implementing.

         

        I cannot find mention of R30 anywhere but, if I have missed the reference, it is a typing error, 9 and 0 being next to one another  on the keyboard.

         

        Also on this question I note what I think is a typo on your part.  So just to clarify, when you say "pin 12 (on wolfson) to 3" that should of course read "pin 12 (on pi) to 3"  .... ie as per the pcb layout above.

         

        So to answer your question directly, your approach is one of several possible equally valid solutions.  I would not underestimate the hardness of the component, nor the risk to the PCB, but it is your call.

         

        For the approach that you are proposing,  the description of Hias on page 7 of this thread seems to answer your needs the best.

         

         

         

         

        John

        • 271. Re: New reworked driver for Wolfson/Cirrus Logic audio card
          soundhound

          hi John

          the R30 is in there a few times! but belonging to Matthias.

          here's the full thread:

          New reworked driver for Wolfson/Cirrus Logic audio card

           

          I should have said soldering point on the 40pin wolfson  connecter that mates with pin 12 on the Pi, to pin 3 of. P5!

          that's right, isn't it?

           

          on your circuit diagram above, it appears to me that the wolfson pin 12 goes to pi pin 33.

          how is it that p33 doesn't figure in the other two solutions, R39 and trace cut?

           

          thanks again.

          chris

          • 272. Re: New reworked driver for Wolfson/Cirrus Logic audio card
            psyj

            Chris

             

            Hi .  I am pretty sure it is R39 is the one to go,  perhaps Hais could confirm (The reason I am not 100% certain is that my solutions do not involve a board modification, so I have never done this myself). It is R39 that connects the 8804 (spdif controller) to GPIO A (ie pin 12 of the 26 way header). R30 is the pull up resistor on the same line (which, if memory serves me correctly, Hais says to leave:- which would make perfect sense)

             

            Yes, that is right, pin 12 of 40 way connector to pin 3 of the 8 pin header.

             

            Your reading of my pcb is correct. That connection is there for completeness  ...... the board is designed to make the Wolfson card resemble the Cirrus card as closely as possible  ..... but the current (and all previous versions) of the linux driver do not use this line (hence why removing R39 and leaving a weak pull up , R30, is a completely acceptable solution)

            • 273. Re: New reworked driver for Wolfson/Cirrus Logic audio card
              hiassoft

              psyj  schrieb:

               

              I am pretty sure it is R39 is the one to go

              Yes, it's R39. It's on the backside of the PCB, located next to R30, near the mounting hole. Here's a picture:

               

               

              so long,

               

              Hias

              • 274. Re: New reworked driver for Wolfson/Cirrus Logic audio card
                soundhound

                John, so you're saying the pin 33 connection is redundant?  thanks

                • 276. Re: New reworked driver for Wolfson/Cirrus Logic audio card
                  psyj

                  Hias,

                   

                  Where can I find the parameter set generated by the driver (and modified by cset commands) please? I need to populate a database of current values and parsing the plain text output given by "amixer -Dhw:0 scontents" takes a great deal of effort

                   

                  My intention is to continue "-Dhw:0 cset commands to control the device,  but tracking revisions through scontents does not seem wise

                   

                  Many thanks

                   

                  John

                  • 277. Re: New reworked driver for Wolfson/Cirrus Logic audio card
                    hiassoft

                    You can use alsactl store to get a complete dump of the current mixer settings. eg:

                    /usr/sbin/alsactl store -f my-settings

                     

                    This'll create a simple to read and parse text file. Linux distributions also use that to get persistent mixer settings across reboots. On shutdown they call alsactl store, on boot alsactl restore.

                     

                    If you are interested in specific changes from the mixer scripts just call them with sh -x,. eg "sh -x ./Playback_to_Lineout.sh" and watch for amixer calls.

                     

                    so long,

                     

                    Hias

                    • 278. Re: New reworked driver for Wolfson/Cirrus Logic audio card
                      psyj

                      Hias,

                       

                      Many thanks for that alternative approach, it does seem to provide a more readable text file than "amixer -Dhw:0 scontents". My only problem is that it is still a huge file to parse (27000+ lines, 500k file)  ...... but I will see if it parses more easily/ more rapidly.  Either way many thanks,  I will let everyone know how I get on  ..... my final objective is to generate a GUI based on php/html in order to control the device in a rather more informative way than alsamixer.

                       

                      Regards

                       

                      John

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