---
updatedAt: 2025-11-07T19:57:08.000Z
agentTools:
  projectIndex: https://developer.validic.com/llms.txt
---

# Passive Read

Flutter ==> Bluetooth module

Some Bluetooth peripherals support passive reading (collecting readings without the app in the foreground). For information on permissions setup and other requirements, please review the [iOS](https://helpdocs.validic.com/docs/native-ios-mobile-inform-sdk-bluetooth) and [Android](https://helpdocs.validic.com/docs/native-android-mobile-inform-sdk-bluetooth) native documentation.

To start passively listening to certain peripherals, pass an array of `peripheralIDs` to `ValidicBluetooth.setPassivePeripheralIDs()`:

```
// Set passive peripheral IDs to be scanned and read from in the background
await ValidicBluetooth.setPassivePeripheralIDs(peripheralIDs);
```

To stop passively listening, pass an empty array:

```
// Set passive peripheral IDs to be scanned and read from in the background
await ValidicBluetooth.setPassivePeripheralIDs();
```

## iOS Background Mode

Passive Reading requires that an additional Background Mode capability be added to a Flutter application's `Info.plist` before BluetoothPeripherals can be monitored.

```
<key>UIBackgroundModes</key>
<array>
	<string>bluetooth-central</string>
</array>
```

Additionally, a privacy usage statement must be added.

```
<key>NSBluetoothAlwaysUsageDescription</key>
<string>Allow reading from bluetooth peripherals in the background</string>
```

The host application must be at least launched in the background for readings to be collected from devices when they advertise an available reading

## Android

If the host application is closed by the user and a Bluetooth Peripheral advertises a new reading the App will relaunch and collect the reading.

## Special Considerations

> 📘 Special Considerations
>
> Please review the [native Android](https://helpdocs.validic.com/docs/native-android-mobile-inform-sdk-bluetooth-behavior) and [native iOS](https://helpdocs.validic.com/docs/native-ios-mobile-inform-sdk-bluetooth-behavior) documentation for details on special considerations for specific peripherals.