How to self-made a knob to control volume

**silencery** · 03-09-2005, 02:58 AM

ball mice w/ scroll wheels are your best bet. There's a lot of info in my sig.

**rubicon** · 03-09-2005, 03:39 AM

Ok, so here's some info, for those of you who

don't want to purchase the Phidgets encoder
have a bug up your butt about doing this yourself (like me!)

Parts as listed in previous post; see attachments for pic of (probable) circuit and (rough) software to get useful info out of the parallel port.

The software is still academic - I haven't gotten my encoder, yet.

But it reads the (currently bogus) data from the parport just fine, and the encoder connection should be a snap. Oh, and it polls the parallel port - not optimum, but seems to be not such the resource hog that I thought it'd be.

Note: Please don't ask me how to get this stuff to run on your machine - if I can figure it out, so can everybody else.

Note #2: This completed whatchamathingy will be included in a post about my car pc install when said install is completed. No idea when that'll be; hopefully soon!

Note #3: the encoder I'll be using is kind of pricey (~$20) for what you get; I'm sure that a more economical version would work just fine, with appropriate circuit/software modifications.

**silencery** · 03-09-2005, 03:48 AM

rubicon,

I don't know if you're open to the idea, but you can do the same thing w/ a rotary encoder from an old mouse (scroll wheel). You can use girder's mouse plug-in to manipulate the events, and it will even give you advanced control options like a powermate (turning cw, ccw, turning while holding down the knob, etc).

All in all, the project should cost about $5.00 for the mouse and $20.00 for girder. Of course, it's even better if you can find an old ball mouse lying around; you can simply hack that up. If you like, you can hook up an external knob to the PCB of the mouse to replace the stock mouse encoder. All you have to do is hook up the appropriate leads.

**0l33l** · 03-09-2005, 03:51 AM

If you're going with the phidgets rotary encoder, why not just go all out and get the 8/8/8 kit. I'm pretty sure that you'll find good uses for the other features

**rubicon** · 03-09-2005, 12:26 PM

silencery: I appreciate the thought, but two things keep me from using a mouse wheel+girder (or the like):

Its Windows only (no MS operating systems allowed here, folks). I follow the *NIX philosophy of "one tool for one job" - a daemon to monitor & process outputs from the encoder, another for the IR remote, another for the GPS, etc.
I have in my mind the way I want this project to look+function, and a hacked-up mouse wheel doesn't fit into the plan. Plus, if all I did was assemble *everything* from off-the-shelf components without putting a little of my own blood, sweat, and tears into the mix, I'd be no better than the Teutuls (the OCC folks).

That's not to say that using the mouse wheel+girder isn't a good option - its just not for me.

**silencery** · 03-09-2005, 01:44 PM

Yeah, i can respect that

I simply offered the suggestion in case that was what you were looking for. Clearly though, you're much more hardcore than i thought!!

**rubicon** · 03-09-2005, 10:28 PM

Sweet - worked first time!

Got my order from Digikey today, including the Grayhill encoder. Using the circuit & software in my post above, I get "CW rotation," "CCW rotation," and "button pressed" events from the encoder via the parport.

W00t!

On a related note, I absolutely detest soldering.

**Frigor** · 03-15-2005, 11:17 AM

Originally Posted by silencery

If you like, you can hook up an external knob to the PCB of the mouse to replace the stock mouse encoder. All you have to do is hook up the appropriate leads.

And where do you find the grip handle?
I was thinking to hack the cigar lighter one, but if there is a site (shipping to italy) wich sells this items...

@rubicon: congratulations for your volume project!

**silencery** · 03-15-2005, 11:33 AM

Frigor,

As you might have seen on my gallery post, I just used the stock knobs that came with my radio. You can generally use anything that's an encoder though... A griffin powermate is the same.

I picked up the mouse for you, BTW. Let me know if you still want it.