Port classes are the keybrd library’s interface to I/O expander ports.
To write your own port classes:
For example, the keybrd_DH library use these keybrd classes for its PCA9655E I/O:
Debugging I/O expander code is hard because SPI or I2C protocol adds a level of indirection. If you haven’t written Arduino code for an I/O expander before, learn from an Arduiono I/O expander tutorial before attempting it here.
keybrd tutorial by Wolfram Volpi is licensed under a Creative Commons Attribution 4.0 International License.
Permissions beyond the scope of this license may be available at https://github.com/wolfv6/keybrd/issues/new.