{
  "params": {
    "state": {
      "type": "choice",
      "options": [
        "red",
        "amber",
        "green",
        "off"
      ],
      "default": "red",
      "label": "State",
      "describe": "Which lamp is lit: red (stop), amber (get ready), green (go), off (dark, out of service). The pedestrian head shows red for red and amber, walk green for green."
    },
    "arm": {
      "type": "choice",
      "options": [
        "pole",
        "overhang"
      ],
      "default": "pole",
      "label": "Mount",
      "describe": "pole (head on top of a 3 m kerbside post), overhang (tall mast with a horizontal arm holding the head over the lane)."
    },
    "housing": {
      "type": "choice",
      "options": [
        "black",
        "yellow",
        "green",
        "grey"
      ],
      "default": "black",
      "label": "Housing",
      "describe": "Colour of the signal housing and visors: black (Europe), yellow (North America), green (old town), grey."
    },
    "pedestrian": {
      "type": "toggle",
      "default": true,
      "label": "Pedestrian head",
      "describe": "Adds a small two-lamp walk / don't-walk head and a push button lower on the pole."
    }
  },
  "presets": {
    "go": {
      "state": "green"
    },
    "overhead signal": {
      "arm": "overhang",
      "housing": "yellow",
      "pedestrian": false
    },
    "out of order": {
      "state": "off",
      "housing": "grey"
    }
  },
  "night": {
    "lit": {
      "zone": "lit",
      "intensity": 1.6,
      "describe": "The lit lamp (and the lit pedestrian lamp) glows in its own colour."
    }
  }
}