PineTab (aka Quirky Devices)

[zhaofengli]

So I recently got a PineTab, which is an ARM tablet with a detachable keyboard dock (see picture, the magnetic connector is actually USB). It has the following quirks:

The native orientation is rotated by 90 degrees

(Yes, that's the native resolution - 800x1280)

Because we use the normal orientation to decide whether to enable the keyboard, we need to

• a) allow the user to specify "the orientation at which the keyboard is disabled" - easy but confusing ("why is my normal not 'normal'?"), or
• b) allow the user to specify a rotation applied to the vector before deciding the orientation - less confusing

Actually, as the keyboard can be detached, we should have a feature where we lock the rotation to the normal human orientation when an input device is present (in this case, the USB keyboard).

Edit: Wanted to set up everything again half a year later, and saw this silliness. Please, ignore my brain fart 😆 There is no need to normalize anything, or flip the axes. In fact, the current code in src/main.rs is over-complicating the thing by comparing the vectors.

[zhaofengli]

Still WIP, but I've made some changes to accommodate PineTab and similar devices:

Use the correct accelerometer value scale

Not all devices have the accelerometer raw values between 0 and 1 (e.g. PineTab). The correct scale is accessible via sysfs.

Revamped keyboard mode system

I added --keyboard-mode, which can be one of:

• integrated: The keyboard is an integral part of the device. We will disable the keyboard when the screen is not oriented upright.
• detachable: The keyboard is detachable. We will keep the screen oriented upright when the keyboard is attached.
• none: We won't touch your keyboard.

After-rotation hook (#4)

You can specify a command to be run in shell after rotation with --rotate-hook. Useful for forcing a restart of Polybar, for example.

[thurstylark]

I also have issues with the accelerometer value scale. For my hw (Lenovo Yoga 920), /sys/bus/iio/devices/iio\:device0/in_accel_scale contains 0.009806650

I believe all that's necessary is to replace / 1e6 with a multiplication of whatever value is read from in_accel_scale:

rot8/src/main.rs

Lines 260 to 262 in b7b42d9

	// Normalize vectors
	let x: f32 = (x_clean as f32) / 1e6;
	let y: f32 = (y_clean as f32) / 1e6;

---

Edit: Actually, it should be (raw + offset) * scale

Reference: https://wiki.analog.com/resources/tools-software/linux-drivers/iio-inertial-measurement-units/adis16400#show_channel_value

[efernau]

thanks for your commit, sadly not merged.
your problem should now be solved with --normalization-factor and --invert-y. the idea with the after-rotation hook and the keybord mode should be implemented. but the change of -k would be a braking change, see this in the planned rewrite version 0.2.0.