All Dyson fans make use of a local messaging protocol titled MQTT, the internet standard for IoT communication across devices. Dyson's protocol is relatively simple and its MQTT topics are extremely easy to parse as it is sent in JSON format. This wiki documents the findings of Dyson MQTT messaging available to clients. Note however that Dyson4J makes every attempt to abstract away this messaging protocol in an object-oriented-friendly manner rather than exposing raw JSON content. This wiki exists as a way to publicly document the findings of the protocol as the library was developed over time.

All message topics are prefixed with the Dyson fan's unique product code (Typically a 3-numbered sequence, possibly prefixed with an alphabetical character), and the plain-text username of the Dyson fan. Both the product code and username can be found on the fan's label at the front of the device as such:

All message JSON payloads will be formatted with at least the following JSON:

{
    "msg": "<message_id>",
    "time": "2022-09-10T02:45:00.000Z (ISO formatted date)"
}

Some messages may include (or require) additional key-value pairs, but ALL messages will include the msg id, and the time at which the message was dispatched.

Used to send commands to the Dyson fan. There are two supported message ids accepted on this topic

Upon receiving this message, the Dyson fan will update the state of all settings included in the message's data object. An example message may look like this:

{
    "msg": "STATE-SET",
    "time": "2022-09-10T02:45:00.000Z",
    "data": {
        "fmod": "FAN",
        "fnsp": "0080",
        ... etc ... All fields are optional
    }
}

All known message fields and values are as follows:

Upon receiving this message, the Dyson fan will respond with two messages on the /status/current topic (see below) including the fan's current state, as well as the fan's environmental sensor data. This message requires no additional data. An example message looks like the following:

{
    "msg": "REQUEST-CURRENT-STATE",
    "time": "2022-09-10T02:45:00.000Z"
}

Used to receive messages from the Dyson fan after a REQUEST-CURRENT-STATE message on the /command channel (see above). Either one of two messages can be received on this channel.

This message is sent by the MQTT server (the fan) when the REQUEST-CURRENT-STATE message has been sent on the /command channel.

{
    "msg": "CURRENT-STATE",
    "time": "2022-09-10T02:45:00.000Z",
    "mode-reason": "PUI",
    "state-reason": "MODE",
    "dial": "OFF",
    "rssi": "-58",
    "product-state": {
        "fmod": "FAN",
        "fnst": "FAN",
        "fnsp": "0005",
        "qtar": "0003",
        "oson": "OFF",
        "rhtm": "ON",
        "filf": "0000",
        "ercd": "NONE",
        "nmod": "OFF",
        "wacd": "FLTR",
        "hmod": "OFF",
        "hmax": "2980",
        "hsta": "OFF",
        "ffoc": "OFF",
        "tilt": "OK"
    },
    "scheduler": {
        "srsc": "1ff4",
        "dstv": "0001",
        "tzid": "0001"
    }
}

Additional values in the root object are described as follows:

Most values under product-state are covered under the known values table declared above under STATE-SET, but other states not yet described are as follows:

Values under the scheduling object are not yet well defined.

This message is sent by the MQTT server (the fan) when the REQUEST-CURRENT-STATE message has been sent on the /command channel.

{
    "msg": "ENVIRONMENTAL-CURRENT-SENSOR-DATA",
    "time": "2022-09-10T02:45:00.000Z",
    "data": {
        "tact": "2974",
        "hact": "0053",
        "pact": "0000",
        "vact": "0004",
        "sltm": "OFF"
    }
}

Values found under the data object are described as follows: