Show HN: I built a custom USB Trackball(xythobuz.de) |
Show HN: I built a custom USB Trackball(xythobuz.de) |
> To be able to call this a trackball, we also need some kind of ball or sphere of course. Many people go with the smallest regulation billard balls with a diameter of 38mm.
I will have to do some further experimentation. Thanks!
When I built my mouse (https://jfloren.net/bellwether.html) I found that in the past there were these neat modules which packaged a sensor and a microcontroller on 1 chip, and you basically just had to wire it up to USB -- but those don't seem to exist any more! So I picked essentially the same Pixart sensor as you, used the same leaked datasheets, and built my own. I do wonder why the all-in-one devices disappeared, though.
Actually it seems modern devices use a CCD and then process the image.
Yes, I've also thought about mounting the switches vertically. And more surface should also provide more grip on the table.
Now, I'd love to see a picture of how a hand is supposed to sit above or around this trackball because I can't picture how fingers can comfortably reach the 4 buttons just by looking at their location on the device.
Which leads me to the personal opinion: I think I prefer the design of the testbed over the final iteration. Buttons are missing, I know, but... Here I stand nonetheless.
Using another mouse movement sensor and ignoring one dimension might be simpler for DIY.
I don't understand how to get the stepped motion of the Kensington scroll rings and most mouse wheels. Maybe it has bumps to move past.
In the meantime, enjoy the sweet nectar of an archive.org snapshot link (collected yesterday):
https://web.archive.org/web/20230217104641/https://www.xytho...
Why am I not surprised? I love Germany .
The optics for a quadrature encoder are very forgiving -- it's much easier to implement than the camera-based sensor that's used for position, which requires a plastic lens.
> I don't understand how to get the stepped motion of the Kensington scroll rings and most mouse wheels. Maybe it has bumps to move past.
Most mouse wheels use a mechanical rotary encoder, and the detents are inherent to that part. Some of the fancier ones use custom mechanisms.
I thought about just using a standard mouse wheel sensor, but can't think of a good way to couple it to a big ring. Gears seem like they'd have an annoying amount of play, making it feel indirect.
There are probably two separate optical "gates" in the sensor, separated by roughly half the width of one of the slots.