Re: Mouse encoder?

Arv Evans

If attempting to use a PC Mouse as a rotary encoder and if you are doing
your own software, you do not need to modify the mouse in any way.  A PC
mouse emits character sequences as it moves.  All you have to do is to
write a small bit of software to accept those character sequences and

On Sat, Jul 15, 2017 at 12:07 PM, Mike Yancey <mikeyancey@...> wrote:

I'll say that I have. You're bottom-draggin' if you're not just gonna spend the $3 or whatever for a cheap encoder.
I built the first ARRL Home-brew Challenge project (A complete 40m Transceiver, under $50 ... I know, who'd-a thought back then, I know...)

Steve Weber KD1JV won the project, but one of the challengers was also very popular (a PIC-controlled and tuned version, bJim Veatch, WA2EUJ - I know, I *KNOW*, who'd-a thought of such a thing!)
Anyway, Jim had to scrimp on cost - a US$3 or $4 mechanical encoder would've busted his US$50 budget, what with a US$4.70 PIC, an an MC1350 IF chip, fancy-schmancy AGC, and LCD, etc.
So his project described how to extract the 'encoder' bits from an old-style, "ball" mouse, and re-use it in a $1, throw-away tuning pot. Doing that allowed him to charge that as a 'free' throw-away ball mouse, and a US$1 pot.

Link here:

That said - I tried it... and failed. Just never could get it to work right.

I just used a cheap-o, US$3 mechanical encoder, as my 'budget' didn't need to be EXACTLY US$50.

It's definitely not IMpossible. I would discourage it, mainly 'cause 'just having it work' feels so good (heh).

The TAK-40, btw - I had a PSK31 contact on it (yeah, later wired it with a DDS VFO, and once it was stable I could PSK31) from Dallas, Texas all the way up to Lake Ontario, Canada. Not bad on 5W.

Link (and proof!) here:

The BITX40, however - far, far, far superior SSB. I much prefer using it, particularly with the dual gel battery, 22 watt version.

Mike Yancey, KM5Z

Dallas, Texas

On Fri, Jul 14, 2017 at 05:05 pm, Dexter N Muir wrote:

This is just speculation, I haven't tried it myself having not yet delved into the programming to activate it:
Has anyone tried the guts of a PC-mouse as an encoder? I'm thinking a mouse with scroll-wheel (most have a mild 'detent' feel) - perhaps an old(er) ps/2 plug type? Use a ps/2 socket to retain the 'foolproof' pluggability. Disconnect the wiring (maybe leave supply + and -), and wire out the opto's of the wheel. One will be SDA, the other SCL. Perhaps also a/the button/s? one as encoder's 'push' menu/function for step-change etc (I'd use the right for that), the other (left being more intuitive for the more prevalent dexterous :) of the populace) for a convenient PTT... Note: will they pull up or down?
That's 6 wires (if the PS/2's connector pins are all wired through the cable - they might not for a mouse) - SDA, SCL, +5V, 0V, menu and PTT.
If your scrapped mouse is a 'track-ball' type, remove the ball to remove the temptation from the kids to swap it to their old 'junker' PC. Pop in a large nut from the garage/workshop's junk-heap to lend weight if required.
Feedback? Flames? Go to it ...



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