esphome/tests/components/matrix_keypad/test.esp8266-ard.yaml

packages:
  common: !include common.yaml

matrix_keypad:
  id: keypad
  rows:
    - pin: 12
    - pin: 13
  columns:
    - pin: 14
    - pin: 15
  keys: "1234"
  has_pulldowns: true
  on_key:
    - lambda: ESP_LOGI("KEY", "key %d pressed", x);