MIDIbox SEQ new frontpanel idea

[mongrol]

Nice work! To boost structure it could be worth digging into the mechanical keyboard scene to see how they fabricate rigidity. I expect to reduce the rear standoff (Mongbox was really tricky to arrange, even with just the Wilba CS) some kind of cut alu plate or perhaps just acrylic backplane woud be needed. This would make the height of a desktop unit even higher. Lowest I could get Mongbox was 42mm.

[u-link]

The Mechanical Keyboard Scene (didn't even know this is a scene til two days ago ...) do seem to use something like this:

http://smg.photobucket.com/user/WhiteFireDragon/media/keyboard/IMG_1828.jpg.html

https://geekhack.org/index.php?topic=36907.0

 

 

[u-link]

I sent keycapsdirect a mail if they do the DSA keycap with ALPS mount in a relegendable transparent form and if so, how much. Best would actually be to have a transparent top and nontransparent sides to reduce spill.

[latigid on]

@mongrol I was indeed wondering about a backplane with sparser mounting holes to fit a Core etc. under. Hanging the encoders off the front panel would strengthen the aluminium and provide another anchoring point for PCBs. 

@u-link Yep, that's what the right-hand PCB in my previous image is doing. The switches "plug" into that and then get soldered onto the other one. The mech switches are fairly tall, so this allows the encoders to rise a bit. Thanks for contacting keycapsdirect!

 

The good thing we've got going is the PCBs are about half the size that they use in smaller mech keyboards.

E.g. pok3r has just 6 mounting holes and what looks like 3 little shelf parts on the edges (295*102mm)

 

Low profile alu case here

 

In that sense maybe all of those mounting holes on my design are a bit much.

I'll look at building in the MIDI IO, maybe a BLM port, but the Quad IIC will be a bit too much. This means the aux encoder boards would be amalgamated. I think there should be three encoders max per line, and without switches (no menu switching functions with encoders, right?). Instead I can add two extra switch footprints to fill up a DIN, and an RGB LED with dedicated DOUT pins. In this case all of the DIN routing would be on the top board and all of the DOUT on the bottom.

[u-link]

Some extra switches will be necessary I guess, to exit an eventual 4x16 BLM mode. Imagine being able to program drums in a tap mode with 4 velocity levels directly from the front panel, with the LEDs lighting in time with the rhythm, indicating the programmed velocity level!

[mongrol]

I asked on reddit about "shorter" rectangular keycaps but didn't get much luck.

Thread here. 

https://www.reddit.com/r/MechanicalKeyboards/comments/5ekerd/rectangular_keycaps/

Relgendable caps here  (down bottom)

http://www.fentek-ind.com/keys.htm

[mongrol]

10 hours ago, u-link said:

Some extra switches will be necessary I guess, to exit an eventual 4x16 BLM mode. Imagine being able to program drums in a tap mode with 4 velocity levels directly from the front panel, with the LEDs lighting in time with the rhythm, indicating the programmed velocity level!

The "track" encoders that replace the track buttons could be clicky. Or clicky the datawheel.

[latigid on]

Good idea to ask the experts! 

As far as I can make out a "1x spacing" key should fit just fine in the x and y dimensions. Somewhat uncannily the spacing of 19mm used to match the encoders to the display pixels is standard for keyboard layouts(!)  Still need to do proper measurements in the z direction though. Note the encoders and display will sit somewhat higher as they're on the "mounting plate." The switches probably need to be ALPS mount to work. Cherry MXs have a smaller but square profile leaving little room for stacked headers etc.

A clicky data wheel's a good idea. I can put the footprints in for switched encoders that can be enabled with solder jumpers, maybe optionally joined to the "fast" buss instead. You can fit non-switched in place of course. Another degree of freedom is the encoder shaft -- the shorter the better though (less wobble).

Preferences for switches? Easiest is standard 6mm and DT6.

A tip for DIY blank keys from a yobbo: 

 

FWIW, don't expect megabit colour depth unless we use fancy PWM drivers in place of shift registers.

 

[mongrol]

On 11/24/2016 at 10:50 AM, latigid on said:

 

 

 

What do you mean by 6mm ad DT6? Where?

More importantly what's the plan for the Oled's? The diagram looks like they are above the switch PCB and up against the encoders. To support the switch PCB you need standoff's underneath and if you use screws to secure it, you'll foul the little angle feet things on the bottom of the oled PCB's. 

Can oled's be mounted upside down and made to display upside down? If so, there's much more room on the top flange with about 9mm clearance before you hit the little angley feet things. I've got one here in a bag, I'll take a pick later.

[latigid on]

6mm tact swtich:

 

DT6:

 

 

 

 

I can use multi-format footprints for a few different switches. The arrangement would offer a choice between encoders and switches in line with the aux encoders (left and centre).

At the moment, the LCD is a standard size of 182*33.5mm, although I've come across a few OLEDs that can have a larger mounting PCB. That could be problematic. I think a neutral colour will be best e.g. black on white or vice versa.

It'll certainly be a big puzzle to get all the pieces fitting together with proper clearances.

Did anyone contact Fentek yet?

 

[mongrol]

Ok. So the switch footprints can be Mattius (alps), 6mm tact and/or DT6. Nice.

I just had a look at the Mattius page and they seem be pumping the backliight support. Other than being transparent it seems how to mount the LED's are left as an exercise. I guess leaning on the mechanical keyboard crowd will again be beneficial. :)

What do we want from Fentek? I'm happy to send queries but until we have requirements nailed it'll be a bit vague.

I do like the look of SigPlastics G20 keys. Flat and square but they don't do a translucent version.

[latigid on]

On 25/11/2016 at 10:48 AM, mongrol said:

Ok. So the switch footprints can be Mattius (alps), 6mm tact and/or DT6. Nice.

Not quite. Here's the current design:

 

At the left and centre you have two sets of multi-functional pads; from these you can select a maximum of 8 DINs. So 4 encoders, 8 switches or combinations of these. You'll have to configure them with jumpers.

 

Newest design:

Same deal, you see one half as the switch board, one as the "panel" plus encoders/aux switches. I've reverted to Cherry MX switches as they're more widely available and have more options for caps. Speaking of caps, X-keys (did somebody mention them already?) look okay. Transparent would be needed I suppose.

http://xkeys.com/accessories/Keycaps.php

 

Something to note is the boards would need to be stacked before soldering in the switches (I found you can socket MXs too if this is a problem) and screwed in from the outside of the case. You see that I've considered a new carrier board for the Core as well to fit between mounting standoffs. If I can find one I'll also look at vertical PCB mount SD cards to have that accessible on the front, otherwise the carrier PCB goes beyond 100mm and is more expensive. USB would be via a micro to type B or OTG connector.

I was hoping one of the PCBs would extend past the displays to hold the MIDI connectors. Seems that's too hard, so I'll make another board with 8 DINs on it. These can be configured as 4 IN/4 OUT or an octal I2C -- the latter probably with yet another board holding PIC16F or something better. Of course fewer DINs are also possible. One set of IO can be subbed for a BLM connector or other peripherals. 

Here's a rough sketch of the internal heights:

You can see a 3mm panel, the switch mounting, ALPS STEC12 (STEC11 off to the left) with Re'an P401 knobs, LCD, OLED (thinner) and a MIDI socket hanging off the bottom. Total height might be about 40mm. I'm a bit uneasy about the distance of cutouts to the panel edge, but there are other strategies like using a U-shaped case where the bend adds some strength. 

The OLEDs I found normally have an annoying extra 5mm added to the PCB height, which is okay if you're building a Ponoko/Formulor case but not good for fixed rack units. The following displays should fit as they maintain a standard PCB size of 182*33.5mm:

Cheapest and crappiest.

http://www.buydisplay.com/default/character-display/40x2-character
 

 

MIDAS do a black on white transflective LCD that looks nicer:

http://www.midasdisplays.com/pdf/MC24005A.pdf

 

Even better is this OLED:

http://www.lcd-modules.com.tw/page/product/show.aspx?num=183&kind=59&page=1

It doesn't seem to be available anywhere so I've sent an enquiry.

 

 

 

[mongrol]

Good work. I must admit you've now lost me with this jigsaw puzzle. Having trouble visualising it all. I might break out Blender this week and have a go at 3d modelling it.

That Oled above looks totally different to the standard Midas/Raystar/Winstar/Vishay layouts. lcdmodules = 33.5 depth vs 38.5

Edit: Can we use this for the "Play" button?

http://xkeys.com/accessories/KnifeSwitch.php

 

Edited November 27, 2016 by mongrol

[latigid on]

Sorry for the confusion and crappy orthographic projections. To get a better idea, look for teardowns of various mechanical keyboards. You'll see the intermediate "plate" for mounting cherry switches -- normally piece of sheet metal. In this SEQ build, you'd need two switch/register boards, two plate/encoder boards, two LCD/OLEDs, Core, MIDI IO etc.

That's the good thing about the Sunlike OLED :). The bezel is a bit larger, but a similar thickness and they've managed to maintain standard 33.5mm PCB height. It's really an OLED as there's no connection to B+/B- (normally pins 15/16). If you've got a spare 5mm in your case the more common ones will do, though I'd prefer a neutral colour like black/white.

 

30 minutes ago, mongrol said:

Edit: Can we use this for the "Play" button?

http://xkeys.com/accessories/KnifeSwitch.php

• Rated for 2,400 VAC @ 908, 200 mA

 

Fun times!

 

Edited November 27, 2016 by latigid on

[u-link]

Hi there, Signature Plastics answered the following (my request was for something fitting the Matias-mount): 

They have a non-recessed fitting mount style available, and

"We can make relegendable keys with
the EX mount. It is unfortunately not possible to make the keys with a clear
top  - the relegendable top is clear, but the bottom of the relegendable is
opaque. We can however mold the base out of clear material to make the
entire keycap transparent. Is this something you are interested in? We have
a minimum order value of $100, but I can't give pricing until I know which
route you want to go (opaque base or transparent base).
Thanks!"

 

 

 

[latigid on]

On 30/11/2016 at 5:30 PM, u-link said:

Hi there, Signature Plastics answered the following (my request was for something fitting the Matias-mount): 

They have a non-recessed fitting mount style available, and

"We can make relegendable keys with
the EX mount. It is unfortunately not possible to make the keys with a clear
top  - the relegendable top is clear, but the bottom of the relegendable is
opaque. We can however mold the base out of clear material to make the
entire keycap transparent. Is this something you are interested in? We have
a minimum order value of $100, but I can't give pricing until I know which
route you want to go (opaque base or transparent base).
Thanks!"

 

Hey, thanks for the update. As mentioned, it's looking like the switches will be Cherry MX or equivalent. Also, a recessed mount would be better (have a look at the panel spacing image above), but in any case, there won't be any "front panel" around the keys as there's no room. A good compromise I think would be to use black or dark PCBs for the "switch panel."

Any thoughts on the "X-keys" linked above? They come out at 50c each, though that's without any bulk discounts requested. It'd be good to get proper dimensions of them, but they look to have a lower profile than other caps, also a few mm less in the x/y dimensions.

As far as colour goes, that's a tricky question! How about a milky type of plastic in a neutral colour? The light would then be better diffused than with full transparency. Also, one could paint/spray paint a darker colour over the the translucent cap bottom -- the opposite of what the guy did in the video above. If possible, please get some pricing from them!

Before big decisions are made it would be nice to test out a switch and check the illumination with a given LED.

 

I've requested samples of the white on black OLED above.

No luck with a vertical socket for SD Cards, although there is one for microSD. Hack approach:

 

Same principle as using an old floppy cable, but not a great idea as you'd need the panel precise, one of the contacts removed and a plastic guide to align the pins properly. Does the SD have to come out to the panel? It would be easier and cheaper to have a microSD sitting in a normal or hinge type socket. Otherwise you get another PCB breaking out an SMT SD socket to header pins that are soldered or socketed on the main PCB.

 

The following being the idea of socketed SD:

 

 

 

 

Edited December 4, 2016 by latigid on

[latigid on]

I found the following imgur album a good representation of X-keys clear caps:

http://imgur.com/a/gTpfd

Even a tight layout of 18mm works okay:

 

without caps there's notable hotspots on the clear caps (could be the photo/camera settings):

 

In the dark:

 

From this angle you get the idea of the "switch mounting panel"

 

 

The black painted keys with translucent "negative" labels look the best IMO.

 

Apparently RS used to stock these, I can't find them anymore

 

Back to X-keys, result isn't too bad with mostly black legends:

 

Looks like quite a bit of colour bleed; fine for bling RGB where you want a rainbow effect, less so for individual indication.

 

 

Edited December 4, 2016 by latigid on

[Hawkeye]

I like the bling! :-) Cherry switches are awesome, at least much better than the switches we use (and which keep failing) in the current seq frontpanel pcbs ;-).
Many greets!
Peter

[ilmenator]

2 hours ago, latigid on said:

Looks like quite a bit of colour bleed; fine for bling RGB where you want a rainbow effect, less so for individual indication

That's quite a lot of bleed, indeed. Maybe reverse LEDs that are mounted underneath the PCB (and that shine their light through a hole in the PCB) could be an option to have a more directional light beam up into the clear "dome"?

[latigid on]

@ilmenator, it's a bit of a toss up, because the bleed likely doesn't come from the bottom (the mounting plate blocks most of the light) but spills over the whole clear switch top. By design the caps sit 3mm above meaning there's a lot of chance for wandering photons. For mech key dudes, I bet part of the appeal is having a coloured "skirt" of light at the base.

The Gateron or Zelio switches have a large cutout lending themselves to other LED options, maybe a narrow angle THT RGB LED raised as high as possible. The downside being it makes hotspots more likely unless there's good diffusion. 

 

Cherry MX normal with LEDs

https://geekhack.org/index.php?topic=54702.0

 

 

Edited December 4, 2016 by latigid on

[latigid on]

Round and round and back again...

ALPS/Matias seem to do a better job, because you can reverse-mount the LED right in the centre of the switch. Cherry MX have a stabilising pin there.

(clicky one)

 

https://www.youtube.com/watch?v=qfwJBpeT6TE

 

A real pity about the fewer cap options though.

 

[latigid on]

I asked Fentek, keycaps direct and X-keys if they have ALPS mount and different plastics available. 

I've ordered a few Matias and Cherry MX switches to test.

FWIW, the keyboard above can take both Cherry MX and ALPS switches. The backlighting uses a kludge method of bending an LED into the hole normally holding the Cherry MX post. Ideally I'd prefer to have as few PCB holes as possible to make routing easier, so I'll first look at a topside LED under the switch. Other options are "dead bugging" an RGB LED, using "chiclets" holding an easily soldered 5050 mount + pin headers, or even columns of 4. 

PLCC would be great if only they had reverse-mount styles, but I can't find any in RGB. In this case it might work to use normal LEDs and attach them with cut resistor legs spanning across the "bottom" and making the solder connections. After the chip was secure, you'd carefully cut the wires apart as not to short the pins.

[Antichambre]

Hi latigid on,

If you plan to use MX format, I've found an easy way to add velocity sense to it.
I told about it in the wilba's topic "Cherry Jammer Blog".

Last week, I received PCB for test and it works fine...

I'll explain everything when back home...
 

Edited December 5, 2016 by Antichambre

[latigid on]

Nice work! What sort of layout were you going to do? An isomorphic or square grid? Presumably you'll need a clear housing the bottom (or holes drilled) to get the LED shining through, or do you plan to use other switches (e.g. Gateron)? 

[Antichambre]

4 minutes ago, latigid on said:

What sort of layout were you going to do? An isomorphic or square grid?

A module of 16 MX in line, like the OLRE ;)

 

5 minutes ago, latigid on said:

Presumably you'll need a clear housing the bottom (or holes drilled) to get the LED shining through, or do you plan to use other switches (e.g. Gateron)? 

You can find gateron for rgb smd led:


Or use the common pinned RGB led for MX:


My small board accepts both solution, I need to test if red spectrum of the leds will perturb the infrared detector...