App idea: Bluetooth trackpad

[yerpj]

Hello.
Yesterday, I was walking around with my 3-month-old baby crying in my arms, while trying to browse YouTube's ‘Watch Later’ section on my phone. Yes, I'm a bad father, but that's not the point ;-)
The fact is, it's not practical at all with half a hand. I would have loved to have an input device connected to my phone that could move the cursor, scroll and click, and I just realised that this could be possible with a bangle.js 2 held in one hand.

Do you think it's possible to get the x, y and press events from the Bangle touchscreen and translate them into a trackpad-type device so that the phone can be controlled remotely with the bangle?

[gfwilliams]

Yes, absolutely! There's already a HID keyboard&mouse mode. Nobody uses it in an app yet but it should work according to https://www.espruino.com/BLE+Keyboard#combination - you can use one of the other Bluetooth keyboard apps as an example of how to do it.

But once it's enabled, this function should work if you call it from the drag event.

/**
 * Moves the mouse. If no button is specified the internal holding buttons are used, 
 * set by startHolding() and stopped with stopHolding().
 * @param {number} x - The relative amount to move in x-axis. (-127 to 127) 
 * @param {number} y - The relative amount to move in y-axis. (-127 to 127) 
 * @param {number} [b] - The buttons to hold during this movement.
 * @param {number} [wheel] - The relative amount to scroll vertically. (-127 to 127)
 * @param {number} [hwheel] - The relative amount to scroll horizontally. (-127 to 127)
 * @param {function()} [callback] - Function to call when bluetooth message is sent.
 */
exports.moveMouse = function(x, y, b, wheel, hwheel, callback) {
  if (!b) b = holdingButtons;
  if (!wheel) wheel = 0;
  if (!hwheel) hwheel = 0;
  NRF.sendHIDReport([1, b, x, y, wheel, hwheel, 0, 0], function() {
    if (callback) callback();
  });
};

[bobrippling]

Taken Gordon's code and tweaked it into an app - PR here if you'd like to check it out

[yerpj]

Great, thanks for sharing! I tested it, but I couldn't get it to work on my Windows PC. However, I didn't have time to look into it further.
Has anyone else encountered the same problem?

[thyttan]

It's now merged and at the app loader: https://espruino.github.io/BangleApps/?q=hidmouse

It needs Settings->Bluetooth->HID set to keyboard and mouse.

[gfwilliams]

Great, thanks! Some other HID apps check the state of the HID setting at startup and offer to change it, so it could do that I guess?