Bluetooth known issues

1. Bluetooth does not work.

Like Wi-Fi adapter, the support for bluetooth adapter in Linux varies greatly, depending on hardware vendor support. So the first thing to check is whether your adapter is supported by the Linux kernel.

Intel-based adapters usually work very well with few exceptions. All you need to ensure is you have the latest firmware.

Broadcom-based adapters are very quirky. Some requires firmware that is not publicly available - you need to fish it out from somewhere else (e.g. Windows drivers); and you need to use special tool to upload it to the the adapter. Fatdog64 includes two of those tools: brcm_patchram_plus and brcm_patchram_plus_usb but due to great variation between models, they may not work.

Run dmesg in a terminal and check for signs whether the kernel detect problems with your adapter.
Run "hciconfig hci0 up" in a terminal and see if you have got any error messages.

2. Where is the bluetooth applet?

In Fatdog64 800, the bluetooth stack (bluez) is updated to version 5.50 (older Fatdogs used bluez 4.101). This is a major change, and the bluetooth applet used in previous versions does not work with the new bluez. Thus it has been removed. Starting from Fatdog 812, we now have a Simple Bluetooth Manager as a replacement, which can do most of the tasks that the bluetooth applet used to handle. The manager can be found in the Control Panel, or it can be launched from terminal as The manager will work both on GUI and in console terminal.

In addition to the simple manager (and for earlier versions of Fatdog before 812), Fatdog offers an extensive CLI-based management for bluetooth devices. Aside from bluetoothctl, bluez's own CLI tool (which is much improved than older tools), Fatdog64 includes bluez-tools (bt-adapter, bt-device, bt-network) which makes most bluetooth operations such as pairing, connection, and disconnection very simple.
To find out nearby device: bt-adapter -d (press Ctrl-Break when done)

To pair with nearby device: bt-device -p XX:XX:XX:XX:XX:XX  (where XX:XX is the bluetooth mac address you get from discovery process, above).

To connect: bt-device -c XX:XX:XX:XX:XX:XX (this works for all devices: mice, keyboard, speaker, etc)
To disconnect: bt-device -d XX:XX:XX:XX:XX:XX

To view all existing paired device: bt-device -l  (this is lower-case L, not a capital i).

To remove a paired device: bt-device -d XX:XX:XX:XX:XX:XX (where XX:XX is the bluetooth mac address from the list, above)

3. My adapter is supported but it does not work. I plugged it in after the system is up and running.

You need to bring the device up: "hciconfig hci0 up". This is usually done at boot-up but if you haven't plugged automatically, it can't be done, so you will have to do it manually.

Also, if you plan to connect to a bluetooth speaker, then you need to restart the bluetooth service: service bluetooth restart . This is because bluealsa (the component that provides bluetooth audio support) will fail to start if there is no bluetooth adapter; so you need to restart the entire stack.

4. "Setup Bluetooth Modem", in the Network tab, in Control Panel, does not work.

It might as well probably be. Due to the major upgrade between bluez 4.101 in earlier Fatdogs and bluez 5.x in Fatdog 800 and newer, the modem setup GUI may not work anymore.
Unfortunately, we can neither test it nor fix it, as we no longer have a device that can be used to test this functionality, so you are on your own.
The relevant function is located in /usr/sbin/ and /usr/sbin/fatdog-bt-find-dun.awk, if you want to troubleshoot it yourself. Don't forget to send a patch if you make it to work.

5. My Microsoft Bluetooth Mouse does not work.

Certain bluetooth mice, such as some models of MS mice, requires the "uhid" kernel module to work. Otherwise, they can pair, trust and connect, but they will not work.

The solution to this problem is:
  1. To load the uhid kernel module. This can be done by running modprobe uhid in terminal, or, you can do this automatically at every boot by editing /etc/modules and adding a line containing the word uhid all by itself.

  2. Then, you need to edit /etc/bluetooth/input.conf and uncomment the line UserspaceHID=true (remove the # in front of it), and then restart the bluetooth service (do that from Control Panel --> System --> Manage Servers and Services).

6. How to listen to music on my bluetooth speakers/headphones?

Bluetooth audio has its own support page, here.

7. I paired with my phone, but when I tried to send files, my phone cannot see my computer.

The problem is the computer device class, which is advertisement of what the computer can do (to other devices). The default value is 0x000100, which only identifies it as a computer, but does not include any capabilities. Some phones can cope with this, some cannot.

To be able to send/receive files, the computer needs to advertise that it supports Object Transfer (that is, file transfer). To do this, please set the computer device class to 0x100100 using the Simple Bluetooth Manager (if you want to do this yourself, edit /etc/bluetooth/main.conf.

You can synthesise the required device class value by looking at this website:
Other good source of information is available in ArchWiki Bluetooth article as well (but not all of them are applicable to Fatdog, especially the one concerning systemd, because Fatdog does not use systemd).