I am using a Raspberry Pi 2 Wheezy with a Bluetooth dongle to capture data from an ELM 327 OBD.

I can list the OBD device but I am unable to connect to that through Bluetooth. I am getting an error like:
Console snapshot

Can't connect RFCOMM socket: Host is down

Please help me to solve this.

  • what bluetooth dongle are you running? Jul 18, 2017 at 5:36
  • also can you please share the result of the following command hciconfig Jul 18, 2017 at 5:39
  • 1
    Why not dist-upgrade from "wheezy" to "jessie"? This is so that you move to the current (Raspbian 8.x) version - and given that Raspbian tracks the upstream Debian distribution we'll get "Stretch" (9.0) sometime soon: raspberrypi.org/forums/viewtopic.php?f=66&t=186300
    – SlySven
    Jul 20, 2017 at 23:05
  • +1 for upgrading to Jessie as Wheezy is no longer receiving updates. Jul 24, 2017 at 1:26

1 Answer 1


This was tested is Jessie rather than wheezy but should still work. See image below for an example but type:

$sudo systemctl start bluetooth
$sudo bluetoothctl
#power on
#agent on
#scan on
$sudo rfcomm connect 0 MAC_ADDRESS 1

I have obscured MAC addresses and device names because it is a client's device.

enter image description here

  • We also got the same in Jessie but need to implement the same in Wheezy. Jul 19, 2017 at 11:12
  • Unfortunately I don't have any experience with Wheezy and I don't have time to set up a Pi with it on. I would suggest looking at any Bluetooth tutorials which pre-date Jessie's release (Approx September 2015) such as this one to see if they do anything similar to what you're tying to do. If you could post some information on what dongle you are using and what steps you have already tried that might help other users as well.
    – pfl
    Jul 19, 2017 at 12:03
  • Also when you try my answer in Wheezy does the bluetoothctl work or does it give any error messages?
    – pfl
    Jul 19, 2017 at 12:04

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