Pairing Xperia 10 II with HC-05 did not work (Bluetooth)

[Grayling]

Hi,

I’m trying to do app which read some sensor data from bluetooth signal coming from HC-05 bluetooth module which is controlled by arduino device.

But I got stuck right at the start. My Xperia 10 II did not pair with HC-05. It did find the device and when trying to connect, it will first ask password and then it shows ~2 second like connection was made, but then it disconnect and say nothing. Although it shows HC-05 in the list of paired devises. When trying to connect again it says something like “can not connect, make sure device is on…”. When I put HC-05 on AT command mode, it shows like there has never been connection between these two devices (which is probably true).

I tested and with android device there is no problem to pair it with HC-05, so module it self should be ok, right?

I’m not professional developer, more like beginner. And I have no idea where the problem is or how to start fix it. So if you can help me, please do it that simple I can understand.

I maybe should mention that pairing Xperia with my computer works as it should. So at the moment problem is only with HC-05.

[direc85]

You could try to pair it using bluetoothctl, see for example:

Broken pairing, no connection with Bluetooth car kit [10 III, 4.4.0.68]

It is in bluez5-tools. Install with devel-su pkcon install bluez5-tools Then start it (with root priviledges, i.e. after devel-su) with bluetoothctl Then use the following commands: scan on - to start scanning When the car kit is discovered (its MAC address and name will be shown) type pair [MAC address] to start pairing then trust [MAC address] to make the car kit a trusted device and finally, if it disconnects and does not reconnect automatically connect [MAC address] to reconnect, …

[Grayling]

I tried, but it did not work.
It shows like pairing goes well (HC-05 does not agree with this), but fails when trying to connect:

[bluetooth]# connect XX:XX:XX:XX:XX:XX
Attempting to connect to XX:XX:XX:XX:XX:XX
[CHG] Device XX:XX:XX:XX:XX:XX Connected: yes
[CHG] Device XX:XX:XX:XX:XX:XX ServicesResolved: yes
Failed to connect: org.bluez.Error.NotAvailable
[CHG] Device XX:XX:XX:XX:XX:XX ServicesResolved: no
[CHG] Device XX:XX:XX:XX:XX:XX Connected: no

Also tried to set HC-05 as a master so that connection attempt would come another way around. Same thing happened; phone shows “connected: yes” and after a second “connected: no” again.

[Grayling]

Hi. This project has been aside for a while, but now I’m back and going to have a new attempt to make this work.

With my laptop (Linux Mint 20.1) I can make similar pairing and then make connection by:
$ sudo rfcomm connect /dev/rfcomm0 [bt-addr]
After that I can test connection for example by reading rfcomm0 -file like this:
$ cat /dev/rfcomm0
And the “Hello!”-message from HC-05 shown up to the screen.

When trying to do same thing with my xperia rfcomm says:
“Can’t create RFCOMM TTY: Operation not supported”

Any ideas why it is not supported?