If you are just getting started troubleshooting your device's Bluetooth problems, look here first: Troubleshooting Android Bluetooth Connection Issues
If none of the above steps work, you may be able to clear your device's Bluetooth cache.
Clear your bluetooth device cache and/or data
These screen shots will not match your device exactly, and not all Android devices will allow you to clear their Bluetooth cache and/or data.
1. Open the Android Settings App.
2. Inside the settings App search for 'Apps'.
3. Click the 'Apps' option:
4. Inside the Apps manager tap on the more menu ( 3 dots ):
5. Tap 'Show system':
6. Search for the 'Bluetooth Share' App ( sometimes it can be named differently ) and Tap it:
7. Tap on the 'Storage' option:
8. Tap on 'CLEAR CACHE' to clear your device cache. This will not disconnect any other devices and should be tried before clearing your device data:
9. Reboot your phone.
10. Retry connecting to your pHin monitor or pHin bridge.
11. If clearing your device cache does not solve your problem, tap 'CLEAR DATA' to clear all Bluetooth device data. Please note that this will disconnect and un-pair all previous bluetooth devices ( smart watches, speakers, etc. ). You will need to manually reconnect each device after clearing your Bluetooth device data:
12. Reboot your phone.
13. Retry connecting to your pHin Monitor or pHin Bridge.