MMI style rotary encoder install - details and photos
This is the solution I have been using for the last 18 months, and I would like to share more information on what is a very reliable and flexible solution. (Installed in an Audi coupe).
Also my apologies for "dipping in" to some previous discussions and not following it up with detail.
What I wanted was an encoder that could be used in all situations e.g. menus, audio/video scrubbing, navigation zooming etc - think audi A8 MMI
I looked at the powermate but it all looked too "locked down" in terms of what comes out of the box. For my install it was also a little too large...
The solution came with the girder "mouse" plugin by J Hind. This allows the scroll-wheel and buttons to take on different roles such as cursor up.
So, you buy a mouse with a scroll wheel. You buy an alps 3 pin encoder that can be panel mounted. You remove the cheap and fragile 3 pin scroll-wheel encoder inside the mouse, and solder a cable to your panel mounted alps encoder. The encoder has indents, so each "notch" equates to a new line say in a dialogue box.
For mounting, I stripped a cigar lighter for an illuminated "collar" with LEDs and mounted this in an audi TT alloy collar (used for the 5 round switches).
ALPS STEC11B series - RS components (RSWWW.COM) part number 265-2930. If it doesn't work quite right in both directions, don't panic: swap one of the centre and outside pins.
Control Knob - from broken Audi "Symphony" head unit. Fits the APLS shaft very nicely.
LEDS - 5 LEDs provide even illumination at night. I have 4 * connected to the PC "on" output, and 1* connected to my startup PIC unit, which flashes in various states, but is on when fully booted. I like this extra feature!
Mouse modification/Girder plugin.
I bought a 4 button mouse, which allowed me to hard wire three "soft switches" i.e. menu specific, plus the "enter/select" switch of the alps. All these functions can be setup using the mouse plugin by J Hind. Get into enabling and diabling groups within girder and you have a set of controls you can "repurpose" for each application.
In Music/movie mode
Default rotary = scrub up/down timeline
Soft switch 1: Select artist/film (rotary becomes up/down menu)
Soft switch 2: Select track (as above)
Soft switch 3: Eq select (as above)
In navigation mode
Default rotary = zoom in/out
Soft switch 1: Select route (rotary becomes up/down menu) - scans any route on SD card reader
Soft switch 2: "Find nearest" (rotary takes through the various pushpins)
Soft switch 3: Display type (rotary becomes up/down menu)
All told it took about 4 hours to make, 3 hours to wire (and about 4 months to figure!)
More details and tips:
Use the ALPS encoder to replace scroll-wheel encoder NOT X/Y encoders on mouse board.
I have used 3*illuminated switches ABOVE the encoder knob - for me, this is more ergonomic than the audi MMI solution, which places 2 * switches above, and 2 * below the encoder. The switches are round "tactile" illuminated switches which protrude though a bevelled hole. I bought them from RS.
The illumination of the three switches are hard-wired to the "num-lock" "scroll-lock" "caps lock" LED output of a keyboard (you could use other methods such as USB i/o boards). WHY? depending on the menu / sub-menu you are in, only the viable switch options are illuminated. Slight overkill, but looks very slick.
The encoder is a switched version, which provides a good way to confirm selection. Hard-wire to one of the mouse buttons, again controLled by the girder mouse plugin.
Placing the encoder where Audi and BMW place theirs IS very comfortable.
Encoders and soft switches is better than a touch screen. Why?
1) you get used to the position of the encoders and switches so that you can often navigate without looking at the screen.
2) have you tried reading a touchscreen after a week of use? all the thumbprints in sunlight really affect the clarity. Too much cleaning makes for a shiny screen too..
Use Girder! - apologies to any front-end writers are coding for modified mouse boards!