The document describes methods and data formats used by Nwave's cloud-based API broker to relay preprocessed smart parking sensor events to client's endpoints. The data can be passed with or without authorization.

Authorization Methods

1. Basic HTTP(s) Authentication using authorization header in the format of "Basic " + Base64 (username: password)

2. API-Key

Status Change

Event of sensor occupancy status change. Occupation detection time is 5-7 seconds and vacation detection time is 3-5 seconds. 

Method: POST

Body: 

{
  "timestamp": "2019-10-01T18:59:11.254Z",
  "message_type": "status_сhange",
  "message_trace_id": "6c53ce93-27b3-40e4-b012-e4c3d3aea651",
  "message":
   {
     "position_network_id": "6eb6d7d6-e486-45ff-a801-058765e2522a",
     "new_status": "occupied",
     "previous_status_duration_min":36,
     "previous_status_duration_error_min": 1,
     "session_iterator": 1
   },
  "location":
   {
     "latitude": -12.2334134,
     "longitude": 53.743789,
     "level": 3
   },
  "grouping":
   {
     "zone_id": 632,
     "group_id": 10365,
     "group_name": "Position group name",
     "group_inner_id": 16,
     "custom_id": "Position custom ID"
   }
}

• message_trace_id - system message-id;

• position_network_id - parking space network address;

• new_status - parking occupancy status ("occupied" or "free");

• previous_status_duration_min - duration of previous sensor status;

• previous_status_duration_error_min - calculation error of the previous status duration;

• session_iterator - short serial number of parking session. Iterator (number) is incrementing when new parking session starts (0-7);

• latitude, longitude - GPS coordinates;

• level - used for multi-level parking (0 for ground level parking);

• zone_id - id of a device zone;

• group_id - id of a parking bay;

• group_name - name of a position group;

• group_inner_id - a device number inside of a parking bay;

• custom_id - a property "custom_id" of a position.

{
  "timestamp": "{iso8601(message_time)}",
  "message_type": "status_сhange",
  "message_trace_id": "{message_trace_id}",
  "message":
   {
     "position_network_id": "{network_id}",
     "new_status": "{"occupied" if parsed["occupation_status"] is True else "free"}",
     "previous_status_duration_min":{parsed["previous_occupancy_status_duration_min"]},
     "previous_status_duration_error_min": {int(parsed["time_slot_sec"]/60)},
     "session_iterator": {parsed["parking_session_iterator"]}
   },
  "location":
   {
     "latitude": {latitude},
     "longitude": {longitude},
     "level": {level}
   },
  "grouping":
   {
     "zone_id": {zone_id},
     "group_id": {group_id},
     "group_name": "{group_name}",
     "group_inner_id": {group_inner_id},
     "custom_id": "{custom_id}"
   }
}

Heartbeat

The message is sent to confirm health status of a sensor every 3 hours in case of unchanged occupancy status.

Method: PUT/POST

Body:

{
  "timestamp": "2019-10-01T18:59:11.254Z",
  "message_type": "heartbeat",
  "message_trace_id": "6c53ce93-27b3-40e4-b012-e4c3d3aea651",
  "message":
  {
    "position_network_id ": "6eb6d7d6-e486-45ff-a801-058765e2522a",
    "heartbeat_number": 3,
    "status": "free",
    "session_iterator": 1,
  },
  "location":
   {
     "latitude": -12.2334134,
     "longitude": 53.743789,
     "level": 3
   },
  "grouping":
   {
     "zone_id": 632,
     "group_id": 10365,
     "group_name": "Position group name",
     "group_inner_id": 16,
     "custom_id": "Position custom ID"
   }
}

• message_trace_id - system message-id;

• position_network_id - parking space network address;

• heartbeat_number - the value increases for every following heartbeat during single occupancy state (0-11);

• status - parking occupancy status ("occupied" or "free");

• session_iterator - short number of parking session. Iterator is incrementing when parking session starts (0-7);

• latitude, longitude - GPS coordinates;

• level - used for multi-level parking (0 for ground level parking);

• zone_id - id of a device zone;

• group_id - id of a parking bay;

• group_name - name of a position group;

• group_inner_id - a device number inside of a parking bay;

• custom_id - a property "custom_id" of a position.

{
  "timestamp": "{iso8601(message_time)}",
  "message_type": "heartbeat",
  "message_trace_id": "{message_trace_id}",
  "message":
  {
    "position_network_id": "{network_id}",
    "heartbeat_number": {parsed["heartbeat_message_counter"]},
    "status": "{"occupied" if parsed["occupation_status"] is True else "free"}",
    "session_iterator": {parsed["parking_session_iterator"]},
  },
  "location":
   {
     "latitude": {latitude},
     "longitude": {longitude},
     "level": {level}
   },
  "grouping":
   {
     "zone_id": {zone_id},
     "group_id": {group_id},
     "group_name": "{group_name}",
     "group_inner_id": {group_inner_id},
     "custom_id": "{custom_id}"
   }
}