3

Board: Raspberry Pi 3

I have a Pi which is unable to detect any bluetooth peripherals. I diagnosed the bluetooth service by running sudo service bluetooth status which throws the error Failed to obtain handles for "Service changed" characteristics

I'm 99% certain the bluetooth hardware is simply not picking up any devices at all.

Upon closer inspection in the PI itself, I'm able to power on the hardware, and start a scan, however no devices ever appear in the list (even though there are at least 5+ bluetooth peripherals in the room).

Things I've tried to fix it:

  • add the user I'm using to the user group allowed to use the bluetooth hardware
  • Deinstall and reinstall pi-bluetooth
  • Deinstall and reinstall the bluetooth drivers
  • Testing with another Pi to confirm non-hardware issue (the issue seems to lie on the SDCard itself, as it would be pretty weird to have 2 broken Pi boards)
  • Testing with different SD card (same image) (issue persists)
  • Confirm all bluetooth services are up and running (one service gives the error described up top)
  • Stop, reset and restart all bluetooth related services
  • Reboot the Pi
  • Try to scan with WiFi disabled (not working)
  • Inspect with hcitool
  • Scan with hcitool (shows to be scanning, but doesn't find anything)
  • Various different tools
  • Endless searching on google/ stack overflow (results only in people having a slightly different issue)

Things I could try that I've been unable to do yet:

  • Update OS
  • Launch GUI OS interface and try to disable and reenable bluetooth through the GUI interface (startx is not installed)
  • Try getting bluetooth to work with a bluetooth dongle

EDIT: Trying to start a bluetooth low energy scan with sudo hcitool lescan throws the error Set scan parameters failed: Input/Output error A few of the devices in the room are low energy, but not all of them.

EDIT2: Restarting the dbus, hci0 and the bluetooth services fixed this problem, but this scan is also not picking up any devices.

  • Are the devices in the pairing mode? I am not sure you are able to detect them if they are not actively advertising that they are ready to pair. – xmp125a Jan 11 '17 at 15:05
  • 1
    Yes at least one of the device is in pairing mode. It should still detect the others though. – Rob van Dijk Jan 11 '17 at 15:08
  • so it does detect the device which is in pairing mode but not the others? This may be the expected behavior! – xmp125a Jan 12 '17 at 5:38
  • No, sorry for the unclarity, none of the device are being detected, not even in pairing mode. – Rob van Dijk Jan 12 '17 at 8:32
  • Ok, another possible source of the problem: what power supply do you use? Is it at least 2A rated? Try to read the voltages using vcgencmd command after you swich on BT and see if they are as they should be. – xmp125a Jan 12 '17 at 9:43

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