ESPHome Code for MCP23017 Port Expander breadboard test as shown in the YouTube video: https://youtu.be/GyHiSyoyk_0

analog-clock-leds.yaml

# ===============================================================
# Code used in the breadboard test for the MCP23017 Port Expander
# as shown in this YouTube Video: https://youtu.be/GyHiSyoyk_0
# ===============================================================
esphome:
  name: analog-clock-leds
  friendly_name: analog-clock-leds

esp8266:
  board: d1_mini

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: !secret encryptkey

ota:
  password: !secret ota_password

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Analog-Clock-Leds"
    password: !secret ap_password

captive_portal:

# Define I2C
i2c:
  sda: 4  #D1 on D1 Mini
  scl: 5  #D2 on D1 Mini
  scan: true

# Define MCP23017
mcp23017:
  - id: 'mcp23017_01'
    address: 0x20

# Define Outputs (switches / LEDs)
switch:

  - platform: gpio
    name: "Red LED"
    id: red_led
    pin:
      mcp23xxx: mcp23017_01
      # Use pin B0
      number: 8
      mode: 
        output: true

  - platform: gpio
    name: "White LED"
    id: white_led
    pin:
      mcp23xxx: mcp23017_01
      # Use pin B1
      number: 9
      mode: 
        output: true

  - platform: gpio
    name: "Blue LED"
    id: blue_led
    pin:
      mcp23xxx: mcp23017_01
      # Use pin B2
      number: 10
      mode: 
        output: true

  - platform: gpio
    name: "Yellow LED"
    id: yellow_led
    pin:
      mcp23xxx: mcp23017_01
      # Use pin B3
      number: 11
      mode: 
        output: true

  - platform: gpio
    name: "Green LED"
    id: green_led
    pin:
      mcp23xxx: mcp23017_01
      # Use pin B4
      number: 12
      mode: 
        output: true

# Define Push Buttons (Binary Sensors)
binary_sensor:

  - platform: gpio
    name: "Red Button"
    id: red_button
    pin:
      mcp23xxx: mcp23017_01
      # Use pin A7
      number: 7
      mode: 
        input: true
        pullup: true
      inverted: true
    on_press:
      then:
        - switch.toggle: red_led
        
  - platform: gpio
    name: "White Button"
    id: white_button
    pin:
      mcp23xxx: mcp23017_01
      # Use pin A6
      number: 6
      mode: 
        input: true
        pullup: true
      inverted: true
    on_press:
      then:
        - switch.toggle: white_led

  - platform: gpio
    name: "Blue Button"
    id: blue_button
    pin:
      mcp23xxx: mcp23017_01
      # Use pin A5
      number: 5
      mode: 
        input: true
        pullup: true
      inverted: true
    on_press:
      then:
        - switch.toggle: blue_led

  - platform: gpio
    name: "Yellow Button"
    id: yellow_button
    pin:
      mcp23xxx: mcp23017_01
      # Use pin A4
      number: 4
      mode: 
        input: true
        pullup: true
      inverted: true
    on_press:
      then:
        - switch.toggle: yellow_led

  - platform: gpio
    name: "Green Button"
    id: green_button
    pin:
      mcp23xxx: mcp23017_01
      # Use pin A3
      number: 3
      mode: 
        input: true
        pullup: true
      inverted: true
    on_press:
      then:
        - switch.toggle: green_led