I know that the GPIO pins available after PiSound loads are documented at Detailed Specs - Pisound Documentation
However, the documentation says that the blue pins are reserved for PiSound and then lists the following as reserved:
| Pisound |
BCM |
| 11 |
BCM 15 (RXD) |
| 12 |
BCM 14 (TXD) |
| 13 |
BCM 2 (SDA) |
| 14 |
BCM 3 (SLC) |
I can understand the SDA and SLC are used and must not be reassigned to something else, but that other applications can continue to use SDA and SLC for I2C communications.
Is the same true for RXD and TXD?
What does the blue filled in circle mean as opposed to the blue circle with no fill in the GPIO usage diagram?
Hey, the colors in the 40 pin header have the meanings as listed just below the header graphic. Confusingly, the colors of the 14 pin header have different meanings entirely. 
- Black is for the ground
- Orange is for positive power supply (different style for different voltage level)
- Green is for the general purpose pins
- Blue is for communication pins (different style for I²C and UART)
All of the pins on the 14 pin header are fully available for your use, with no chance of interference with Pisound.
Hello is it possible to clarify Detailed Specs - Pisound Documentation with a real gpio picture like this https://www.etechnophiles.com/wp-content/uploads/2021/01/R-Pi-4-GPIO-Pinout-1-768x572.jpg?ezimgfmt=ng:webp/ngcb40 It’s really confusing to me, i would like to add encoders for zynthian with pisound but i don’t know what and where is free. Thank’s
Hi, all of the pins unused by Pisound are routed out to the 2x7 header, they’re listed here.
