# Adding Bluetooth sensors

To add sensors, open the **Organisation Settings** menu. You must have **Administrator** or **Manager** permissions to perform this action.

![](/files/3d4c9eeeed29f401c6033ee718b07bce6fec356d)

## Before you start

Before adding sensors, ensure that:

* A **gateway** (either [Ethernet](/efento-cloud/adding-devices/bluetooth-low-energy-sensors/publish-your-docs-1.md) or [LTE](/efento-cloud/adding-devices/bluetooth-low-energy-sensors/publish-your-docs.md)) has been configured and is active. Additionally, the sensors must be within range of the gateway (approximately **30 meters indoors** and up to **80 meters in open spaces)** to ensure successful connection.
* You have a valid **sensor licence** to add sensors, which can be obtained by entering an **activation code**. If you did not add the activation code during onboarding, you can do it at any time in the **Licence Manager** section.

## Adding sensors

Click the **Add** button next to the **Sensors** field to begin adding a sensor. From the list provided, select the desired sensor and assign it a **custom name** (by default, all new sensors are named "New Sensor"). The sensor’s name, together with its **serial number**, will be displayed on the platform. Next, specify the **location** for the sensor. Once all details are entered, click **Save** to complete the addition of the sensor.

The sensor can be renamed or relocated at any point in time. For a comprehensive guide on how to do this, refer to the [Sensor Configuration](/efento-cloud/advanced/editing-sensor-configuration.md) section.

## Calibrated sensors

Sensors can be purchased with calibration service. If you order a calibrated device, the **calibration certificate** will be automatically available in Efento Cloud. When adding a calibrated sensor to the platform, you will be notified that it comes with a calibration certificate. You can also choose to set a **reminder** to alert you when the sensor requires recalibration. This feature is optional but convenient, as it helps ensure your devices remain accurate without having to remember calibration dates manually.

## Custom formulas / custom measurement types

Efento Cloud enables users to convert raw sensor measurements, such as **pulse counts**, **current (4–20 mA)**, or **voltage (0–10 V)** readings, into easily understandable physical values, making it simpler to interpret the results within the platform.

Additionally, the platform allows you to create [custom measurement types](broken://pages/x9zVgllFe45R0BzJ4W76). These can be used to transform raw data into meaningful units, for example, converting pulse counts into visitor numbers or 4–20 mA readings into wind speed.

If you are adding a sensor that will use formulas or a custom measurement type, ensure that **Channel Redefinition mode** is enabled.

<figure><img src="/files/o474Tq1ZqYJLpdj2AL2s" alt=""><figcaption></figcaption></figure>

## Troubleshooting

When adding Bluetooth sensors to Efento Cloud, you may encounter issues with sensor detection. Use the following guidance to resolve common problems:

* **I don’t see any available sensors to add:**
  * Ensure the **gateway is powered on** and properly connected.
  * Confirm that the **sensors are within the gateway’s range** (approximately 30 meters indoors or 80 meters in open space).
* **I see some sensors, but one of them is missing**
  * Make sure the sensor is **powered on** - the **plastic protective covers** has been removed.
  * Verify that the sensor is within the **range of the gateway**.
  * Ensure the sensor has not already been **added to another Organisation**, as this may prevent it from appearing in your list.

If problems persist after these steps, consult the support team at [help.efento.io](https://help.efento.io) for further assistance.


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