Terminology

The terminology below is largely relevant to developers, the GUI hides it all away.

Wacom Ink devices are Bluetooth LE devices and all communication is wireless. Tuhi uses a number of specific terms to interact with those devices:

Searching means Tuhi is looking for new devices (i.e. those not previously connected with Tuhi)
Registering means Tuhi connects to a new device for the first time.
Listening means Tuhi is listening to data from a registered device.

These three terms reflect some of the user interaction with the device. The actual download of data is handled automatically while Tuhi is listening to a device.

Wacom Ink devices can only be associated with one application at a time. If you are using e.g. Wacom Inkspace, you cannot use Tuhi at the same time (and vice versa). You will need to re-register the device every time you switch between applications.

Searching

When Searching, Tuhi identifies any Bluetooth LE devices within range of the host system. Devices that match the supported devices will be made available to register.

For a device to be identified during Searching, hold the device's button until the blue light blinks.

Registering

When Registering a device, Tuhi picks a randomly-generated UUID and sends that to the tablet. Future communication with the tablet needs to include that UUID. This is not registering the device with some cloud service, vendor, or other service. It is communication between Tuhi and the firmware on the device. It is merely a process of "your ID is now $foo" followed by "hi $foo, I want to connect".

Unlike other Bluetooth devices, Tuhi-compatible devices do not need to be "paired". Hence the choice of the term Register.

For a device to be able to register, hold the device's button until the blue light blinks and make sure Tuhi is Searching. During Register, you will need to press the device's button when prompted.

Listening

Once a device has been registered with Tuhi, you can start and stop Listening to the device. While listening, Tuhi will download any drawings from that device in the background and make those drawings available through the DBus interface.