Tutorial 10 - writing new IOE Port classes

Port classes are the keybrd library’s interface to I/O expander ports.

To write a new Port class:

1. Get a copy of the I/O expander’s datasheet.
2. An I/O expander will use one of two communication protocols: http://www.byteparadigm.com/applications/introduction-to-i2c-and-spi-protocols/. Refer to the Arduino SPI or Arduino Wire (I2C) library
3. Get familiar with your I/O expander. Different I/O expanders use different commands (a.k.a. operation codes). Refer to your I/O expander’s datasheet for read and write commands. Search for Arduino sketch examples containing your I/O expander (sumotoy has a large gpio expander library). Write very simple read and write examples for your I/O expander. Simple SPI I/O expander examples: todo link, pictures /home/wolfv/Documents/Arduino/demo/IOE_MCP23S17_read/ /home/wolfv/Documents/Arduino/demo/IOE_MCP23S17_write/ Simple I2C I/O expander examples: todo link, pictures read write
4. Study other keybrd Port classes. Port classes for SPI MCP23S17 I/O expander: *todo * * Port classes for I2C PCA9655E I/O expander:
   • PortWrite_PCA9655E todo link
   • PortRead_PCA9655E
   • LED_PCA9655E
5. Write similar Port classes for your I/O expander. Debugging I/O expander code is hard because SPI or I2C protocol adds a level of indirection.

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.