> For the complete documentation index, see [llms.txt](https://docs.jcore.io/clarity-gateway/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.jcore.io/clarity-gateway/connections/mqtt/sending-values-to-mqtt.md).

# Sending values to MQTT

In this example we'll configure Clarity Gateway to send the value of an Iron Pi analog input to an MQTT connection.

## Bulk mapping via the channels table

In the page for your MQTT connection, scroll down to the **Channels To MQTT** section. Click the **Show All Tags** switch if it is not already on:

![](/files/WY7DcMTMKwJFgEW43h9r)

All system tags in Clarity Gateway will then appear in the table. In this example we'll be mapping Local I/O channel 1, which is configured as an analog input and mapped to the system tag **channel1**:

![](/files/QdUTVhDffvCaVoZRPo66)

First check the **Enabled** checkbox to enable this mapping:

![](/files/vzrVRXPb9jEJpSNao3Yh)

Then enter the **MQTT Tag** to send values to. In this example we'll use **localio/channel1:**

![](/files/91IcxOAm0TN9TqumcrCb)

Finally, click **Save:**

![](/files/WcF6WyJiRkNylodtRF4s)

Once the mapping is applied, the arrow should change color from gray to blue to indicate that the mapping is active:

![](/files/sYiYdgL4dPfR1nbqXdDk)

## Advanced mapping

For more options when mapping a channel, click the `+` icon in the **Channels To MQTT** section:

![](/files/AAtkzJGvTxD6TeNSWWKI)

This will take you to a separate **Create Channel** page. In that page, first enter the Clarity Gateway **System Tag** you would like to send to MQTT. In this example, we'll be using **channel1**, which is configured as a Local I/O analog input:

![](/files/264E3kXzBjP4RHbKB8vT)

Optionally, you can enter a **Slope** and **Offset** to transform the values that get sent to MQTT. In this example we will enter **2** and **3**:

![](/files/ETVijuAo2dFQZNqKsku1)

Finally, enter the **MQTT Tag** to send to and **Data Type** to use. In this example, we'll send values to **localio/channel1** as **Float**s:

![](/files/CGyvJXPhMdjMEJGfyjb3)

Finally, click **Save** to create the channel:

![](/files/E7wJodtfgywNRrnplzk8)

Once the channel has been created, you will return to the connection page. The new channel should appear in the **Channels To MQTT** table. Notice how the system value is 9.68, and the value sent to MQTT is 2 \* 9.68 + 3 = 22.2:

![](/files/dpaiPEeRGq8lSflGUmid)