Tremors hand/forearm, from either Parkinson’s or Essential Tremors, of 4Hz to 12Hz, makes using a conventional mouse difficult for anything other than large movement of the pointer.
One possible solution is to introduce a microcontroller 'filter', between the mouse and the computer, to filter out some/all of the tremor noise from the mouse and pass the ‘clean’ signal onto the computer. Commercial products are available to provide this functionality but cost $250-$350 per unit. I was hoping to build a similar unit for $50 or less.
Pro: Powered from the PC. No additional software required on PC. It should be relatively inexpensive.
not that it matters (since you can daisy chain usb), but why would you need two ports? wouldn't it just be an inline box?
You'll need to familiarize yourself with how data is transmitted on usb, intercept the signal & modify as you see fit. That's probably going to introduce some lag, though I doubt that'd be a problem for the users this would be for.