Make the move to a split keyboard and the first thing you’ll notice is that you have all this real estate between the two halves. (Well, as long as you’re doing it right). This is the perfect place to keep your cat, your coffee cup, or in [Jacek]’s case, your fantastic DIY trackball mouse.
Don’t be fooled by the orange plastic base — all the electronics are rolled up inside that big sexy ball, which [Jacek] printed in two halves and glued together. Inside the ball there’s an Adafruit Feather nRF52840 Sense, which has an onboard accelerometer, gyroscope, and magnetometer. As you’ll see in the video after the break, the Feather takes readings from these and applies a sensor-fusing algorithm to determine the ball’s orientation in 3D space before sending its position to the computer. To send the click events, [Jacek] baked some mouse buttons into the keyboard’s firmware. Among the other Feather sensors is a PDM MEMS microphone, so detecting taps on the ball and translating them to clicks is not out of the question for a future version.
Here comes the really clever part: there are two reed switches inside the ball. One is used as a power switch, and the other is for setting the ‘up’ direction of the trackball. The ball charges wirelessly in a 3D printed base, which also has a small neodymium magnet for activating the reed switches. Check out the demo after the break, which shows [Jacek] putting the trackball through its paces on a mouse accuracy testing program.
If you prefer your DIY trackballs to be more standard looking, click on over to the Ploopy project.
Would be great for rotation of parts in CAD especially if you could add zoom.
I wonder if you could detect the rotation of the ball in the other axis (as in twist)
It has gyro and magnetometer, so yes.
Very cool! At a first glance, it reminded me of the Microsoft “EasyBall” for Kids from the 90s
Like it, I do love a good trackball, not convinced this will be a good trackball though.
One of the hardest things to achieve that a trackball really needs to be is smooth rolling, 3dprints don’t really lend themselves to that. Also looks like it could be challenging to keep on the desk, being so unconstrained. Also got to to wonder how balanced it is – does it default to the charge direction when left alone, will it stay put in that orientation, and does it roll somewhat on its own sending fake input?
But the idea is really neat, being able to sense more than just x-y movements could be really interesting. I wonder if those internal BB8 droid type mechanisms could be used somewhat in reverse, while still driven for haptic feedback, self correcting charging orientation..
if you were trying to convince me to buy a 2 piece keeb, i think ‘room for your cat’ would definitely get me to part with my money. if you knew how many coding projects they have killed by plopping down in front or on top of my keyboard.
This is a well documented phenomenon: https://www.reddit.com/r/CatsBetweenKeyboards/
lol, you just made my day.