Orange pi Zero 3 pin guide
Pin numbers for the Gpiod plugin:
Notice the GPIO numbers are not as one might often expect.
The notation of the GPIO pins is Group number and Pin number.
For example then for PC9 then 3C is the group number and95 is the Pin number.
To calculate into pin address that we can use then the formula is:
Pin formula
G = Group {(A=0), (B=1), (C=2), (D=3), (E = 4), (F = 5), (G = 6), (H=7), (I = 8)}
X = Number
pin = (G * 32) + X
So if we take PC9 and fill that into the formula then we get:
pin = (2 * 32) + 9 = 73
Pin number 73 is the number we use in the Gpiod plugin then to address this pin.
Voltages
Two 5V pins and two 3.3V pins are present on the board, as well as a number of ground pins (GND), which can not be reconfigured.
Other useful information
If running on Armbian or Debian (and same for many other systems) then for GPIO access you need to run with elevated permissions. (such as sudo)