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MQTT client

The startMQTTClient function connects to a MQTT broker using TCP or TLS.

import { startMQTTClient } from "@devicescript/net"

const mqtt = await startMQTTClient({
    host: "broker.hivemq.com",
    proto: "tcp",
    port: 1883,
})
tip

You can use HiveMQ public broker for testing with public data.

publish​

The publish function sends a message on a topic.

import { startMQTTClient } from "@devicescript/net"

const mqtt = await startMQTTClient({
    host: "broker.hivemq.com",
    proto: "tcp",
    port: 1883,
})
await mqtt.publish("devs/log", "hello")

deviceIdentifier​

You can use deviceIdentifier to uniquely identify the device in the topic

import { deviceIdentifier } from "@devicescript/core"
import { startMQTTClient } from "@devicescript/net"

const mqtt = await startMQTTClient({
    host: "broker.hivemq.com",
    proto: "tcp",
    port: 1883,
})
const id = deviceIdentifier("self")
await mqtt.publish(`devs/log/${id}`, "hello")

subscribe​

The subscribe function creates a subscription for a topic route. The function takes a an optional handler an returns an observable.

import { startMQTTClient } from "@devicescript/net"
const mqtt = await startMQTTClient({
    host: "broker.hivemq.com",
    proto: "tcp",
    port: 1883,
})

await mqtt.subscribe(`devs/log/#`, msg => {
    console.log(msg.content.toString("utf-8"))
})

stop​

The MQTT client will automatically retry to connect once it detects that connectivity is lost. To close the current socket and stop the reconnect task, use stop.

Acknowledgements​

The MQTT client is based on micro-mqtt.