This manual describes the possibility to send measured values via MQTT to the openSenseMap. The openSenseMap is able to connect to a public MQTT broker as an MQTT client. The openSenseMap does not offer an own MQTT broker. The openSenseMap MQTT client connects to a public MQTT Broker with a 13-digit Id with prefix ‘osm_’ followed by 8 random numbers and letters from A to F, unless otherwise specified in the connection settings.

Separate MQTT settings must be made for each registered senseBox. For a connection to a broker the following parameters can be specified. All specified settings are stored in the database of the openSenseMap. It is therefore advisable to set up your own access data.

URL

The address to the MQTT Broker should start with ‘mqtt://’ or ‘brows://’. If the MQTT Broker requires authentication by username and password, these can be encoded in the URL. The URL should then look like this: mqtt://username:password@hostname.of.mqtt.broker

Topic

The MQTT Topic under which the openSenseMap messages should be received can be for example ‘home/temperatures/outside’.

Message format

Here you should choose between ‘json’ and ‘csv’. The formats correspond to JSON array and csv documented in docs.opensensemap.org.

Decoding options

Expecting a JSON object. For json message format only: Allows a JSONPath expression to be specified under the jsonPath key, which specifies the position of the JSON-encoded data. Example: {"jsonPath":"$.payload_fields"}

Connection options

Expecting a JSON object. Allows to pass connection options to the MQTT client. The keys keepAlive, reschedulePings, clientId, username and password from https://github.com/mqttjs/MQTT.js#client are allowed.