Improved MCP23017 implementation for Home Assistant

• Async implementation (more reactive and nicer to HA)
• Thread-safety allows different entities to use the same component
  • Fix issue #31867
• Config Flow support (UI configuration) in addition to legacy configuration.yaml.
• Push iso pull model for higher reactivity, e.g. 100ms polling for 'zero-delay' push button without loading HA.
• No dependencies towards AdaFruit libraries
• Optimized i2c bus bandwidth utilisation
  • Polling per device instead of per entity/8x gain, register cache to avoid read-modify-write/3xgain or rewriting the same register value)
• Synchronization with the device state at startup, e.g. avoid output glitches when HA restart.

1. Add https://github.com/jpcornil-git/HA-mcp23017 to your custom repositories

1. Clone or download all files from this repository
2. Move custom_components/mcp23017 to your <ha_configuration_folder>, e.g. /home/homeassistant/.homeassistant/custom_components/mcp23017
3. Restart HA and clear browser cache (or restart a browser); latter is required for new config_flow to show up
4. Add mcp23017 component using:

• config flow (Configuration->Integrations->Add integration)
  • Created entities will be visible in the Integrations tab and aggregated per device (i2c address) in the Devices tab. Entity options (invert logic, pull-up, ...) can be adapted using the entity's Options button once created.
• configuration.yaml see configuration example below.
  • Syntax is compatible with the legacy implementation described in https://www.home-assistant.io/integrations/mcp23017/

# Example configuration.yaml

binary_sensor:
  - platform: mcp23017
    i2c_address: 0x26
    pins:
      8 : Button_0
      9 : Button_1
      10: Button_2
      11: Button_3
  - platform: mcp23017
    i2c_address: 0x27
    invert_logic: true
    pins:
      8: Button_4
      9: Button_5
      10: Button_6
      11: Button_7

switch:
  - platform: mcp23017
    i2c_address: 0x26
    pins:
      0 : Output_0
      1 : Output_1
      2 : Output_2
      3 : Output_3
  - platform: mcp23017
    i2c_address: 0x27
    pins:
      0 : Output_4
      1 : Output_5
      2 : Output_6
      3 : Output_7