Upgrade old trackball with laser mouse internals?

ZyBeR

15 Mar 2021, 21:12

Would it be possible to take the internals of a laser or other high res optical sensor) mouse and put them in an old trackball?

Or is there perhaps even qmk or other open source firmware compatible hardware out there that could be used?

Rayndalf

16 Mar 2021, 07:46

I believe it can be done (I replaced a ball with a 3360 years ago, used the mouse until a small short made it unreliable and I found a new mouse that was similar weight and size), a modern trackball is a sensor pointed up at the ball and reverses the inputs.

A user on Tindie was selling (may still be selling) breakout boards with 3360 and various other mouse sensors. A laser is good for tracking a smooth ball, but the 3360 should work too.

If you want I'll see what I can dig up regarding DIY mouse stuff. Overclock.net has some info, so does Geekhack.

ZyBeR

16 Mar 2021, 11:01

I would greatly appreciate any help, I just managed to find a brand new DT225 (old bus version) that I want to convert with a high res sensor. I've already got a DT225 USB that I bought new last year which is great, but it would be even better with an optical, high res sensor. I'm also intrigued to try ball transferee units instead of the rollers.

Rayndalf

16 Mar 2021, 11:18

https://www.youtube.com/watch?v=nyb6M89QrWI
This should show the main components (the sensor and code)
There might be better firmware now, but I used this firmware and it worked.

This also looks interesting:
https://geekhack.org/index.php?topic=100027

Basically when converting a ball like this you let the ball roll on the original rollers (the original optical encoders shouldn't provide friction, so just lube them a little and cut anything that gets in the way) and position the sensor under the ball. If you mirror the X and Y axis (because the sensor is upside down so when you move the ball up the sensor views the ball going down) it should work. Only hard part is finding a ball with room for a 3360 underneath it.

I'd need to see some internals to give better help, but wiring the microswitches to the Teensy/Promicro/EliteC or whatever is pretty straightforward, 1 wire for each switch and a shared ground (but you can look into hardware debouncing for switches somewhere on overclock.net)

I'm struggling to find the post now, but a usered named qsxcv did some great work detailing it (incidentally the creator of the firmware used in the video above unless I'm misremembering).

Rayndalf

16 Mar 2021, 11:31

https://www.tindie.com/products/jkickli ... on-sensor/
The part works, but the price hurts

Rayndalf

16 Mar 2021, 12:17

Also I totally forgot, this project also uses a 3360. It's a couple posts under this on the forum, but it looks promising.

viewtopic.php?f=3&t=22899

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