Enum pl_io_port_num contains the list of available 8-bit GPIO ports. Use these constants when selecting the port with the io. object (see the io.portnum property).
Note that GPIO lines are of unidirectional type and require explicit configuration as outputs or inputs. Some lines are configured as inputs or outputs automatically — see Enum pl_io_num for details.
The DS1101 device has the RS232 transceiver IC onboard. This IC "dictates" the GPIO line direction for certain lines. Do not try to use GPIO lines 0, 2, 4, and 6 as outputs — this can permanently damage the hardware.
Enum pl_io_port_num includes only one constant:
|PL_IO_PORT_NUM_0:||8-bit port 0, contains I/O lines 24-31 (the data bus of the OLED display).|