6 Replies Latest reply on May 22, 2017 4:56 PM by marcelheijkoop

    Use of free GPIO ports


      Are there any free GPIO ports that I can use? If so, which ones?


      What would be the best way to use them? Soldering?



        • Re: Use of free GPIO ports

          From the user manual: Cirrus Logic Audio Card User Manual, here is a chart:(15-20 look available)


          Screen Shot 2014-12-29 at 14.57.55.png

          Thanks fvan For showing where.



          PS. the best way is to use headers soldier on so you can connect other cards and/or use them with correct wires.

          1 of 1 people found this helpful
            • Re: Use of free GPIO ports

              Thanks for this answer, which I think is incorrect for my version of the RPi (B+)  but it helped me to find the correct answer.


              Free GPIO pins are connected to the Expansion Header on the Audio Card. The Expansion Header is the header next to the SPKOUT connections. Pin 1 is the pin right next to SPKOUT R+.


              The available GPIO pins are as follows:


              Exp pin     RPi pin     GPIO


              1               2               5V

              2               -                3.3V

              7               6               GND

              8               6               GND

              13             6               GND

              14             29             5

              16             22             25

              17             31             6

              18             32             12

              19             36             16

              20             37             26

                • Re: Use of free GPIO ports

                  Hello all,


                  There is (now after 2 years) another question to that point.

                  In addition to Wolfson CLAC on my RPi 2 B Model, i want to have a 2*16 LCD beeing fed via 4bit mode.

                  In total, this requires all of the six free pins left on Extension Pin Header. (mentioned above, GPIO 5,25,6,12,16,26).

                  That means: no GPIO left! But in the same time there i need another three GPIO PINs to be used for user interaction.


                  I already regret having decided for CLAC because of this design aspect that i was not aware of in advance.

                  But I looked in the manual


                  and found another free PINs "unused" (GPIO 4,27,24) (on page 15 of 21). Those are not available on the expansion header.

                  What is your guess, may it be possible to use them e.g. by contacting via a (not yet designed) break-out PCB?


                  Thanks for your contribution!