Bluezog
A Bluez implementation in Golang
What is this?
Do we need another Bluetooth implementation in Golang? I think so, but maybe not this one. But, in the absence of another one, this one exists.
There is more than one way to access your bluetooth devices on Linux, but I think using Bluez over D-Bus is pretty clean. The big drawback is that it needs D-Bus, which is basically just Linux.
Goals
Bluez is the linux library that runs over D-Bus. If this client can be minimal and testasble, it should be easier to debug. Bluez is well documented, and this library will only provide that. Perhaps, specifications on top of bluetooth, like iBeacons and Eddystone, can be done in examples.
Alternatives
- gitub.com/go-ble/ble (which is forked from github.com/moogle19/ble ... which is forked from github.com/currantlabs/ble. The two forks were last updated in April and Janary of 2020.
- github.com/raff/goble and github.com/paypal/gatt. (MacOS and Linux, respectively).
- github.com/muka/go-bluetooth: This uses D-Bus.
Of course, there may be others. go-bluetooth uses the same approach. Namely, Bluez and D-Bus. But, it didn't work out of the box, so I fixed it and made a PR. Then it still didn't work. I tracked down the error, but, at that point, it seemed to risky to continue down that path, so we went with go-ble because it basically worked.
Dependencies
- godbus: A nice golang interface to D-Bus
- testify: I like this for testing
- readline: This is for the command line interface. Ideally, it would be a selective dependency, or the CLI tool could be a separate module. But, this can really make module fetching messy.
Testing notes:
-
device /org/bluez/hci0/dev_FF_F2_DF_D8_10_D4 connect This works, but it seems like it's not getting the alert when it is initially found. But it's in the cache. This is one of my ble beacons. No UUID shows up.
- cached devices are in /var/lib/bluetooth, under the adapter.
Omron USB ?: /org/bluez/hci0/dev_FF_F2_DF_D8_10_D4 service: /org/bluez/hci0/dev_FF_F2_DF_D8_10_D4/service000e characteristic: /org/bluez/hci0/dev_FF_F2_DF_D8_10_D4/service000e/char0019
Omron Bag: Path: /org/bluez/hci0/dev_D1_40_FD_DE_C6_1C LegacyPairing: %!s(bool=false) Connected: %!s(bool=false) Address: D1:40:FD:DE:C6:1C Alias: EnvSensor-BL01 Blocked: %!s(bool=false) Adapter: /org/bluez/hci0 AddressType: random Paired: %!s(bool=false) Trusted: %!s(bool=false) UUIDs: [00001800-0000-1000-8000-00805f9b34fb 00001801-0000-1000-8000-00805f9b34fb 0000180a-0000-1000-8000-00805f9b34fb 0c4c3000-7700-46f4-aa96-d5e974e32a54 0c4c3010-7700-46f4-aa96-d5e974e32a54 0c4c3030-7700-46f4-aa96-d5e974e32a54 0c4c3040-7700-46f4-aa96-d5e974e32a54] ServicesResolved: %!s(bool=false) Name: EnvSensor-BL01
Usage:
- GATT: Depending on the hardware, which might be by the name of the object, or the Manufacturer Data, you need the UUID of the GATT Service, Characteristic, or Descriptor. The FindObjects method on protocol.Bluez is perhaps the primary way to get the device. You will cast it to a protocol.Device.
commands: list path org.bluez.Device1 object /org/bluez/hci0/dev_D1_40_FD_DE_C6_1C dump list path org.bluez.GattCharacteristic1
This one seems to be valid (but crashed because the in param was nil?)
object /org/bluez/hci0/dev_D1_40_FD_DE_C6_1C connect 0c4c3000-7700-46f4-aa96-d5e974e32a54
Currently crashing on some reflection error. Probably because I don't know what
to pass into ReadValue
gatt /org/bluez/hci0/dev_D1_40_FD_DE_C6_1C/service0026/char002d
adapter start object /org/bluez/hci0/dev_D1_40_FD_DE_C6_1C connect 0c4c3000-7700-46f4-aa96-d5e974e32a54 stop
I think the ALPS is: SNM00 ( /org/bluez/hci0/dev_48_F0_7B_78_45_5E)
The UUID isn't in the main advertising data, so you can connect to it without a profile object /org/bluez/hci0/dev_48_F0_7B_78_45_5E connect
Then the GATT objects will be added