OBD ELM327 bluetooth cannot connect

[Maister]

Hey guys!

I just bought two different OBD-II bluetooth adapters, which are compatible to the ELM327.
I have a R-pi 3 with the latest raspbian downloaded and installed bluetooth and blueZ.

The issue is that I cannot connect to anyone of them. When I scan for bluetooth devices I can find them, but while pairing it says: "the device is not offering any service the raspberry pi can make use of" and then connection aborts.

Any one knows how to fix this? Or is it simply that I got the wrong devices ?

Thanks for any comments and answers..
Patrick

[seanzhang1212]

I am facing same issue....and found it might caused by RASPBIAN has no full support of bluetooth devices with current version. Only bluetooth keyboard / mouse / headset are supported right now...This was announced with May 2016 release, but there's a new release now so you might could try with the latest RASPBIAN and see is it supported.

[Douglas6]

Raspbian fully supports the Serial Port Profile that OBD devices use. The GUI does not support them; you'll need to set up SPP and rfcomm yourself. See if this thread helps: viewtopic.php?p=947185#p947185

[Maister]

Thank you Douglas6,

I tried all you mentioned in the linked thread. I get stuck at connecting to the device with bluetoothctl.
It pairs successfully and I trust the device. When attempting to connect, it will connect for a sec and then disconnect with Error message:
"Failed to connect: org.bluez.Error.NotAvailable"

Any further idea to this ?

[Douglas6]

Yeah, don't try to connect with bluetoothctl. Use rfcomm.

[Maister]

Ok, when I type

Code: Select all

sudo refcomm watch hci0

it says:
"Waiting for connection on channel 1"
and blocks the console.

I wanted to use this along with py-OBD: http://python-obd.readthedocs.io/en/latest/

When I try via obd.OBD() or do the obd.scan_serial()
I get no connection and no serial devices, respectively.
Maybe I am thinking fundametally wrong of how to using this.

Is it waiting for me to open a COM port ? Or is it waiting for the device to connect?

[Douglas6]

Instead of the 'watch' command (which waits for another device to make the connection), connect from the Pi with

Code: Select all

sudo rfcomm connect hci0 AA:BB:CC:DD:EE:FF

This will connect and create a virtual serial port named /dev/rfcomm0. You can then open the port and read/write to it in Python, or (I'm assuming) use it with an OBD library.

[Maister]

Thank you,
It seems to be getting a connection now. The python OBD lib is detecting it, although it cannot communicate with it, which might be an other problem.

So thank you much! I guess that solved my problem for now

I might try now sending commands on my own without using the OBD lib in the first place. I might as well adjust the baud rate.

[Bleanio23]

Hey guys I had the same problem and did some research. Found the same solution. Have you had any luck getting it to connect with pyobd? I've also been trying to write and run a script for an autostart but so far I've been getting nowhere. Any help is much appreciated..