---
title: USB events
slug: usb-events
createdAt: 2021-10-12T15:19:36.000Z
---

In order to trigger events when the device is plugged in, use the following callback in your mainActivity:

```kotlin
    override fun onDeviceAttach() {
        super.onDeviceAttach()
        //add function here
    }
```

In order to trigger an event when the device is unplugged use the following callback in your mainActivity:

```kotlin
    override fun onDeviceDetach() {
        super.onDeviceDetach()
       //add function here
    }
```



here's an example of a Snackbar UI feedback triggered by USB events:

```kotlin
    override fun onDeviceAttach() {
        super.onDeviceAttach()
        Snackbar.make(
            findViewById<UVCCameraTextureView>(R.id.camera_view),
            "Device Attached",
            Snackbar.LENGTH_LONG
        ).show()
    }

    override fun onDeviceDetach() {
        super.onDeviceDetach()
        Snackbar.make(
            findViewById<UVCCameraTextureView>(R.id.camera_view),
            "Device Detached",
            Snackbar.LENGTH_LONG
        ).show()
    }
```