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Access to 5 GPIO pins with Wolfson Sound Card

Former Member

Raspberry Pi provides GPIO on P1 and P5 connectors. Both these connectors are occupied by Wolfson Sound card.. Two on these GPIO are available on Wolfson card.  In our project we need 5 GPIO. Hence the two questions:

 

1. Of the GPIOs on P1 and P5 which ones are NOT used by the Wolfson sound card?

2. What is the best way to phyiscally accesses these GPIO.

 

We would not be able to use the Wolfson sound card if we do not get access to in total 5 GPIO pins. Please assist.

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  • What is it exactly you need to do with the 5 GPIO ?

     

    As pigraham suggested, there are different ways of getting around the Wolfson occupying all GPIO.

     

    In a project I'm working on, I'm doing the following:

    * Use the Serial Tx/Rx pins which are made available on the Wolfson card for serial communication with an ATtiny

    * Use an Arduino Micro/Leonardo connected via USB as Keyboard emulator in order to pass buttons being pressed to the Pi

     

    Hope this helps image

     

    Frederick

Reply

  • What is it exactly you need to do with the 5 GPIO ?

     

    As pigraham suggested, there are different ways of getting around the Wolfson occupying all GPIO.

     

    In a project I'm working on, I'm doing the following:

    * Use the Serial Tx/Rx pins which are made available on the Wolfson card for serial communication with an ATtiny

    * Use an Arduino Micro/Leonardo connected via USB as Keyboard emulator in order to pass buttons being pressed to the Pi

     

    Hope this helps image

     

    Frederick

Children
  • in reply to fvan

    Thanks for your reply. Here are use of 5 GPIO pins:

     

    1. Panic Buttion  GPI

    2. Buzzer  GPO

    3. Fan control GPO

    4. Shutdown - GPI

    5. Shutdown complete - GPO

  • in reply to Former Member

    I suggest you use a i2c port expander or USB I/O device.

     

    I have a real-time clock module connected to header pins I have soldered onto the Wolfson to connect the i2c. It works and seems to cause no problems with audio.

     

    By soldering two full rows of header pins to the top of the Wolfson you get a stacking connection to support a standard Pi expansion board. As long as any board you add doesn't use GPIO other than the i2c, and doesn't conflict with an i2c address on the Wolfson, it should work.

    IMPORTANT check carefully that any card you attach does not use other GPIO lines or you may damage something.

     

    Insert the pin headers into the female connector of your daughter card to maintain proper alignment. Position the pins over the pins on the Wolfson and carefully solder the pins at each end of each header strip. Solder the pins along the edge then remove the daughter card to access the pins on the inner strip. Be careful not to short the pins solder. Be careful when plugging or removing a daughter card.

     

    You could use the HobyTronics expander in this scheme.