esphome/tests/components/matrix_keypad/test.rp2040.yaml

binary_sensor:
  - platform: matrix_keypad
    id: key4
    row: 1
    col: 1
  - platform: matrix_keypad
    id: key1
    key: 1

matrix_keypad:
  id: keypad
  rows:
    - pin: 1
    - pin: 2
  columns:
    - pin: 3
    - pin: 4
  keys: "1234"
  has_pulldowns: true