Fellowes Opti Trac

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Archie
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Joined: 31 Jan 2019 15:27

Fellowes Opti Trac

Post by Archie » 11 Jun 2019 06:33

Main article:
viewtopic.php?f=25&t=27

I'm not interested in the mouse mode of this device, but unfortunately it's a default one: each time it's connected to PC, after power cycle, reboot, system awake from sleep etc. it resets to the mouse. Another minor issue is mode switching logic: it requires long press of toggle button, not simple click.

Both issues fixed by soldering small 10uF capacitor directly to the toggle switch: discharged capacitor works as initial logic signal when device is powered on, and also 'extends' brief click to the long press needed to perform mode change.

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My hope was that CY7C63743 controller does internally support 4th. mouse button signal (there are some unused GPIO pins): then it would be possible to discard mode toggle functionality and rewire the switch contacts to make right-side button normal Back button. Turned out it is not the case: loaded firmware does not detect any more inputs beyond ones actually present in the device. Well, let's call this button "scroll mode" then! :)

To make device more stable, I've affixed 6 adhesive silicone feet near original teflon ones: now it does not move on the desk.

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Steel bearings replaced with white ZrO2 ceramic 2.0mm ones: as in many trackballs, this operation require drilling of ball cup walls from outside, to push the bearing balls out of sockets.

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Also, I've added pieces of electric tape to the inside surface of buttons, to eliminate free play and provide nice click feel, and slightly lubricated matching edges of case parts to reduce squeaking.

Out of curiosity, I tried to swap original red ball with Elecom dark grey one. It works just fine, and feels a little bit smoother.

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