bug: Already paired devices do not show up when scanning for nearby devices

[mahnuh]

Plugin(s)

• Android Battery Optimization
• Android Dark Mode Support
• Android Edge-to-Edge Support
• Android Foreground Service
• App Review
• App Shortcuts
• App Update
• Asset Manager
• Audio Recorder
• Background Task
• Badge
• Bluetooth Low Energy
• Cloudinary
• Contacts
• Datetime Picker
• File Compressor
• File Opener
• File Picker
• Live Update
• Managed Configurations
• NFC
• Photo Editor
• Posthog
• Printer
• Screen Orientation
• Screenshot
• Speech Recognition
• Speech Synthesis
• Torch
• Zip

Version

7.2.0

Platform(s)

• Android
• iOS
• Web

Current behavior

Already paired devices do not show up when scanning for bluetooth devices.

Expected behavior

I would expect to also see paired devices.

Reproduction

https://github.com/mahnuh/bluetooth-playground

Steps to reproduce

In the example repo:

1. Scan for devices
2. Pair the device (you might need to update things to pair an actual device you have available)
3. Check that device is paired in iOS settings
4. Restart the app and scan again
5. You are not able to see the already paired device and also trying to connect to it will fail with a timeout

Other information

Trying to connect with an AirTurn page turner.

Capacitor doctor

💊 Capacitor Doctor 💊

Latest Dependencies:

@capacitor/cli: 7.2.0
@capacitor/core: 7.2.0
@capacitor/android: 7.2.0
@capacitor/ios: 7.2.0

Installed Dependencies:

@capacitor/android: not installed
@capacitor/cli: 7.2.0
@capacitor/core: 7.2.0
@capacitor/ios: 7.2.0

[success] iOS looking great! 👌

Before submitting

• I have read and followed the bug report guidelines.
• I have attached links to possibly related issues and discussions.
• I understand that incomplete issues (e.g. without reproduction) are closed.

[robingenz]

Thank you for creating this issue. I have just tried to reproduce the problem with our internal example app but without success. The BLE device (Polar H9) is found by the scan even though it is paired (see video).

I also looked at your code and noticed two problems:

1. You call the startScan() method before you have set the deviceScanned listener.
2. In the connect() method, you call the connect(...) method of the plugin without scanning the devices first.

FYI: getConnectedDevices() to which you have established a connection in the current app session.

[mahnuh]

Ok, thanks. I will have a look later tonight and get back to you!

[mahnuh]

It just does not work. Can it be an issue with the device? Even another app is not able to see the paired AirTurn device after a restart... I'll send you a video in Discord.

[mahnuh]

Yeah, it must be the device firmware. I tinkered around with the official AirTurn SDK and with this I'm able to see the device if paired or not. Thanks anyways!