What about the unused GPIO?

The remaining I/O pins are presented somewhere else on the PCB for PiScreens V1 only.
The free GPIO are;

  • GPIO23
  • GPIO27
  • GPIO18
  • GPIO4
  • SDA0
  • SCL0
  • TXD
  • RXD
  • 3.3v
  • 5v
  • GND