Duo LED button matrix pcb group buy

[intellijel]

Ok so on the monome.org list they just put out a new batch of 8x8 monomes and it sold out in 2 minutes. This to me is a little ridiculous for a device that is in my opinion pretty expensive and with limited built in functionality.

Meanwhile there is a simple but great design for a 4x16 matrix by TK that connects to a signifcantly cheaper brain (core) and can functionally do way more.

However, there is no PCB yet. I have little experience doing PCB layouts but I know this design could not be so difficult (maybe I should try! :P). If someone did this up there could easily be a group order put together.

This button array would be useful for tons of midibox controllers (see Robert Henkes Monodeck II)

Any takers?

[bugfight]

hmmm did you search "duo matrix"?

[intellijel]

hehe thanks! I guess I have been out of the loop!!

[intellijel]

ok so I looked at that project and here are my thoughts:

I got suckered into buying a bunch of those sparkfun buttons, pcbs and crappy panels. The pcbs were terribly designed: no extra headers to easily cascade pcbs resulted in messy and cluttered wiring, no space for diodes and the buttons are huge, expensive and chunky. Also the plastic bezzels had many mistakes: (inconsistent hole sizes, poor cutting shapes etc.)

A design based on tact switches with well placed rgb leds will be so much cheaper and require no specialised parts. Each indvidual can choose the type of tact switch actuator they like so long as the footprint is simmilar.

Also I saw no mention of a group buy for the PCBs (which I may as well still buy seeing as I have those expensive sparkfun parts doing nothing right now)

[intellijel]

Also,

As per dicussion surrounding the Ralf Suckow/Robert Henke design for the monodeck II array of rgb leds/buttons:

It would be a great idea to have a controller for seperately dimming the different RGB colours. Also a high power current source/sink.

[Doug Wellington]

Ok so on the monome.org list they just put out a new batch of 8x8 monomes and it sold out in 2 minutes.

I hope Smash doesn't hear about that!  :o

This to me is ridiculous for a device that is so expensive (due to them using expensive manufacturing processes for tiny runs and hand assembly).

Agreed, but hey, more power to them.  I'm waiting for someone else to come along and make a better mouse trap...  ;)

Meanwhile there is a simple but great design for a 4x16 matrix by TK that connects to a signifcantly cheaper brain (core) and can functionally do way more.

Sure...  A couple thoughts:

1) I bought two monome kits and some bare monome buttons.  While I'm building one monome with its USB interface, the other one is going onto my MIDIbox!  And I'm designing a pcb to use the bare buttons in a 4x16 configuration that connects to a MIDIbox core.

2) The monome buttons have an advantage over the Sparkfun ones - they are smaller and the spacing is perfect for using them under a 2x40 lcd.

3) I'm building a sequencer with everything - including a built in 4x16 matrix.  http://www.analognotes.com/mbmatrixseq  If I can work at deal with the monome people, I'll make it with their buttons, otherwise it's lit tact switches...  8)

Doug

[julienvoirin]

Any takers?

I am definitly in !! i started yesterday to design the PCb, with sparkfun buttons.

cimo did a design already, bugfight another for high current leds.

app already exist to make it a cool ableton remote, or a akai mpd. I also have some idea, including a sequencer, BUT without computer behind, opposite to the monome.

they are smaller and the spacing is perfect for using them under a 2x40 lcd.

sparkfun size is he same as the TAP of old electribes, it is better to tap the beat. but sure a display with a good size is a good idea too. personnaly, i will adapt a 4x20 LCD, with 16 encoders for each topic on the display.(no submenu)

[intellijel]

Sparkfun buttons are bad!! They are expensive and huge (and hard to illuminate).

Take a look at the Faderfox LX1 or Lx2.

http://faderfox.de/html/lx1_front_view.html

http://faderfox.de/html/lx2_product_page.html

Those coloured round buttons are tact switches like this: http://dkc3.digikey.com/PDF/C081/P1935.pdf (D6 series)

Here is the data sheet: http://www.ittcannon.com/media/pdf/catalogs/leaf/D6_31Jan.pdf

The advantage of using round buttons is that when you are making panels for them, roundholes are cheaper and easier to make. Just for a test I made a panel in Front Panel designer with 256 holes (128 for the buttons and 128 smaller ones for adjacent leds) and it came out to less than $100.

Other advanatges:

-colour coding: each row or sets or columns can be specific sets of clours

-easy servicing: tact switches are easy to replace. Button pads wear out over time

-Tact switches are really cheap (so are the coloured caps).

The monome has some cool aesthetic qualities and an elegantly simple design but I do not think it is that practical for more complex applications.

So if you make a 8x16 panel with cutouts for 128 switches and 128 leds: <$100

Midibox brains: (core, din and dout)  < $50

128 buttons wht caps <$75

128 duo colour leds <$20

PCBs $????  (I would guess for short run it would be about $75 per 8x16 board but we would probably want a modular system of 8x8 boards)

Suitable case  $????

Once you have the panel made and the switches/leds on a pcb, there are lot's of cheap ways to make enclosures: wood, bent up metal, etc.

So in the end you can make the equivalent of a monome 128 for about $300-400 - and that's for one off costs. If there are group orders we can bring this down to about $250. On top of this it will have duo colour leds (which allows you to make red, green or orange), colour coded buttons AND the midibox brains (which are way smarter than the monome) will allow you to configure the device to generate or respond to whatever midi parameters you want. The monome uses OSC which is a great protocol but limiting (I can't wait until Ableton Live natively supports OSC...we can make waaaay cooler devices then).

[bugfight]

Sparkfun buttons are bad!! They are expensive and huge (and hard to illuminate).

....

pblblblblbllbt!

[intellijel]

huh?

[bugfight]

huh?

hehe, was my raspberry at you poopoo-ing the buttons.

i like em.

don't worry, smashtv will be along any day now to agree with you...

feel free to send your extras to me, along with some bezels which i never did get.

*whack*

[cimo]

on my SF buttons module i use 4 screws to attach it to the sub panel but i ve made all the necessary holes in the pcb to fix the buttons pads to the pcb (as max of 1 screw per button).That should be enough and way cheaper than SF bezels.

I haven t a final box with the SFs so can t judge the buttons but i can say that it looks ok to use them with MBs.I ll let you know asap.

simone

[stryd_one]

tact switches

Barf.

I agree with everything you said but tacts are not the answer. They feel like crap.

Regards,

Your local neighbourhood tact switch hater

;D

Edit: I should say something positive... Has anyone tried either the MEC "Quiet" variant, or the panasonic LTS (Light Touch Switch)? These are tact-like, tact-cheap, tact-size, but supposedly non-clicky... Meanwhile I'm swaying more and more towards capacitative touch sensors for switches... I just don't know enough about it :/ The datasheets for the driver IC's make it look pretty easy though.....

[intellijel]

Tact switches may not be the best feel but they are cheap!

A huge factor is also being able to select colours for the caps. If any of the options you proposed have selectable colours then I would be down with using them.

It's also important to look at the estimated life cycles and required push force specs.

[bugfight]

...

Your local neighbourhood tact switch hater

.....

so tactless

*whack*

[Doug Wellington]

A huge factor is also being able to select colours for the caps. If any of the options you proposed have selectable colours then I would be down with using them

Yet another reason I like the monome buttons...  I might have to experiment with RGB LEDs with these things...

Doug

[julienvoirin]

Hi guys, some of my experience about "buttons".

i make beats on 4 different machines : electribe, akai mpd, machinedrum and kaoss pad.

electribe buttons are the same kind than the ones of SF : rubber. You can easily tap on it, and it make light when there is a note. it is a cool visual feedback. moreover you can tap on it without looking it because you localise the button with your fingers (like a blind man). moreover, they don't produce noise if you play at low level.

IMO, the best deal to design a new keyboard.

machinedrum : classic tact switch, with a spring into and a led for feedback. too much noise at low level, visual feedback hard to feel (it is not what you push that makes the feedback). tapping is not nice on it.

akai mpd : good for beats, large taping size, but no feedback.

kaoss pad 3 : like the Lemur, it is a screen. great versatility, but absolutly no finger feeling. you need to look at the screeen to know where you tap. the screen can give a visual feedback.

So for me, the SF buttons are the best solution. their size allows you to tap fast (you can't push the adjacent button by error). With a duoled inside, you can have a double, or triple (green+red, red, green) feedback.

Designing a PCB of 4x8 allows you to create a square or rectangular keyboard.

It is just my opinion :)

[intellijel]

I agree with what you are saying but the korg electribe series buttons are more like the monome (smaller profile). The SF buttons are not the same, they are about 2-3 times taller,

you are literally collapsing a cube when you press them down.

EDIT - I just tried the buttons again and it is not like ollapsing a cube, more like pushing one.

[cimo]

what s the problem with collapsing cubes ?

  *whack*

remember einsturzende neubaten

[julienvoirin]

i measured the rec button of the EM1 : it is the size of SF (15mmx15mm) : just perfect, like the size of the button of the Machinedrum.

Don't know about the story of the cube. I will get buttons of SF and give a feedback later. On the AKAI MPC1000, it is cube, and i must admit that it is nicer to beat on the MPC1000 than on the MPD where the buttons offers more roughness.

Cheers

[intellijel]

Yet another reason I like the monome buttons...  I might have to experiment with RGB LEDs with these things...

Doug

That doesn't make any sense :P  The monome buttons can't be coloured. I guess you are referring to illuminating them.

[intellijel]

I looked at the Panasonic Light Touch Switches:

http://dkc3.digikey.com/PDF/T081/P1920.pdf

None of them can take caps.

Also the operating force on the ITT D6 series is not that bad (130g) compared to 80g for the Panasonic LTS.

However, the Panasonic style ones are definitley another option. I am focusing more on making a grid with enough spacing so that I can put a stack of sliders on top of it that would line up (e.g. if the buttons matrix 16 columns wide, then 16 faders could be equally spaced so that one lines up with each column)

It would also be cool to make a tiny matrix using the Panasonic LTS and just concentrate on density: make a 16x16 in a small footprint and use 3mm or smaller led. You can make up for lack of button caps with panel graphics.

[julienvoirin]

he still can put gommette on it (round coloured paper circle) : a good way to custmize function on a keyboard

[intellijel]

not a bad idea!

[intellijel]

Update on front panel costs using :

I was slightly mistaken before:

256 round holes (128 for buttons and 128 for leds) is $80  via Schaefer

128 Square holes with tight corner radius in 3mmm aluminum: $107  (almost the same price as buying four of the crappy plastic ones from SF!!)

So really not a huge difference in costs.

If you are trying to make a perfect grid exactly like the monome then the SF buttons are the way to go.

I would rather have a grid that had some seperation in it (like the LX1) since I think this will be easier to use and track for the controller applications I envision.