documented the mqtt.to function, resolves #362

content/v2.0/reference/flux/functions/mqtt/_index.md

@@ -10,6 +10,7 @@ menu:
     parent: Flux packages and functions
 weight: 202
 v2.0/tags: [functions, mqtt, package]
+draft: true
 ---
 
 MQTT Flux functions provide tools for working with Message Queuing Telemetry Transport (MQTT) protocol.

content/v2.0/reference/flux/functions/mqtt/to.md

@@ -7,6 +7,7 @@ menu:
     name: mqtt.to
     parent: MQTT
 weight: 202
+draft: true
 ---
 
 The `mqtt.to()` function outputs data to an MQTT broker using MQTT protocol.
@@ -19,7 +20,7 @@ import "mqtt"
 mqtt.to(
   broker: "tcp://localhost:8883",
   topic: "example-topic",
-  message: "",
+  message: "Example message",
   qos: 0,
   clientid: "flux-mqtt",
   username: "username",
@@ -45,13 +46,20 @@ The MQTT topic to send data to.
 _**Data type: String**_
 
 ### message
-placeholder
+The message or payload to send to the MQTT broker.
+The default payload is all output tables.
+
+{{% note %}}
+When you specify a message, the function sends only the message string to the MQTT broker.
+It does not send any output tables.
+{{% /note %}}
 
 _**Data type: String**_
 
 ### qos
 The [MQTT Quality of Service (QoS)](https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901103) level.
 Values range from `[0-2]`.
+Default is `0`.
 
 _**Data type: Integer**_
 
@@ -61,50 +69,60 @@ The MQTT client ID.
 _**Data type: String**_
 
 ### username
-The username to send to the MQTT Broker.
+The username to send to the MQTT broker.
+This is only necessary when the MQTT broker requires authentication.
 
 _**Data type: String**_
 
 ### password
-The password to send to the MQTT Broker.
+The password to send to the MQTT broker.
+This is only necessary when the MQTT broker requires authentication.
 
 _**Data type: String**_
 
 ### name
-placeholder
+The name for the MQTT message _(Optional)_.
 
 _**Data type: String**_
 
 ### timeout
-placeholder
-Defaults to `1s`   
+The MQTT connection timeout.
+Default is `1s`   
 
 _**Data type: Duration**_
 
 ### timeColumn
-placeholder
-Defaults to `"_time"`.  
+The column to use as time values in the output line protocol.
+Default is `"_time"`.  
 
 _**Data type: String**_
 
 ### tagColumns
-placeholder
-Defaults to `[]`.  
+The columns to use as tag sets in the output line protocol.
+Default is `[]`.  
 
 _**Data type: Array of strings**_
 
 ### valueColumns
-placeholder
-Defaults to `["_value"]`.
+The columns to use as field values in the output line protocol.
+Default is `["_value"]`.
 
 _**Data type: Array of strings**_
 
-
 ## Examples
 
 ### Send data to an MQTT endpoint
 ```js
 import "mqtt"
 
-// ...
+from(bucket: "example-bucket")
+  |> range(start: -5m)
+  |> filter(fn: (r) => r._measurement == "airSensor")
+  |> mqtt.to(
+    broker: "tcp://localhost:8883",
+    topic: "air-sensors",
+    clientid: "sensor-12a4",
+    tagColumns: ["sensorID"],
+    valueColumns: ["_value"]
+  )
 ```