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Appendix F: Using VIA

The A+ Trackball's keymap can be customized using a web application called "VIA". This allows for easy and portable customization of the A+'s buttons.

Currently, a bit of additional work is necessary to get VIA to work, but it should only take about thirty seconds.

Begin by copying and pasting the following into a text file, saving it as aplus.json:

{
  "name": "Ploopy A+ Trackball",
  "vendorId": "0x5043",
  "productId": "0x81DB",
  "matrix": {
    "rows": 1,
    "cols": 8
  },
  "customKeycodes": [
    {
      "name": "DPI Config",
      "title": "DPI Config",
      "shortName": "DPI"
    },
    {
      "name": "Drag Scroll",
      "title": "Drag Scroll",
      "shortName": "DragScl"
    }
  ],
  "layouts": {
    "keymap": [
      [
        {
          "h": 2
        },
        "0,1",
        {
          "x": 0.25,
          "h": 1.25
        },
        "0,2",
        {
          "x": 0.25,
          "h": 1.25
        },
        "0,3",
        {
          "x": 0.25,
          "h": 2
        },
        "0,4"
      ],
      [
        {
          "y": 1.25,
          "w": 1.75,
          "h": 2
        },
        "0,0",
        {
          "x": 1.25,
          "w": 1.75,
          "h": 2
        },
        "0,5"
      ],
      [
        {
          "x": 0.5,
          "y": 1.25,
          "w": 1.5,
          "h": 1.5
        },
        "0,7",
        {
          "x": 0.75,
          "w": 1.5,
          "h": 1.5
        },
        "0,6"
      ]
    ]
  }
}
  • Next, navigate to the VIA web app, using Microsoft Edge, Chrome, or Opera. Any other browser that supports WebHID will work, too.
  • Look at the top toolbar of the web application, and click the tab called DESIGN.
  • Uncheck Use V2 definitions (deprecated).
  • Click Load and upload the aplus.json file that you saved on your computer.
  • Plug in the A+ if it wasn't plugged in already.
  • Look at the top toolbar of the web application, and click the tab called CONFIGURE.
  • Click Authorize Device. A modal window should pop up, and you should see the Ploopy A+ Trackball as an option to connect. Do so now.

You should now see a representation of the buttons of the A+ in the web app. You are now free to modify the button's functionality.

Using VIA and VIAL on Linux

By default, Ploopy devices are compatible with VIA, but not VIAL. However, in both cases, using VIA or VIAL with Ploopy devices on Linux requires modifying a few udev rules. If you have sudo access on your box, the following command will export the necessary udev rules and reload udev:

export USER_GID=id -g; sudo --preserve-env=USER_GID sh -c 'echo "KERNEL==\"hidraw*\", SUBSYSTEM==\"hidraw\", ATTRS{idVendor}==\"5043\", MODE=\"0660\", GROUP=\"$USER_GID\", TAG+=\"uaccess\"" > /etc/udev/rules.d/50-qmk-ploopy.rules && udevadm control --reload && udevadm trigger'

As an alternative, you can use qmk_udev here to perform automated udev access updates whenever compatible devices are plugged in.

If you're looking for more specific advice on configuring udev with VIA and VIAL, see VIAL's documentation on udev here. If you're using VIA, make sure that you follow the instructions allowing VIA devices, as the instructions for VIAL devices are more specific and will not work with VIA.