9 replies to this topic

[TK.]

What do you guys think about following inexpensive solution for a giant 16x16 Duo-LED Button matrix?





I got this inspiration from the Flame Six-in-a-Row project, the creator Per Salzwedel was very helpful and gave me the construction details.


Self-adhesive "3M elastic buffers" (rubber feets) are used as button caps. Costs: ca. 0.06 EUR pp. if we organize a bulk order.
Buttons are "TASTER 3301", available at Reichelt for 0.11 EUR pp.
Single-color LEDs are "SLK 5MM RT", available at Reichelt for 0.07 EUR pp.
For Duo-color (red/green) "LED 5 RG-3" could be used (0.15 EUR pp.), but this one has only a diffuse cap. Does anybody know where to get them with transparent cap?

In addition - and this is the trick! - some kind of transparent silicon mat (german: "transluzente Silikonplatte") is required (2x240x500 mm for ca. 7 EUR) to give a perfect tactile feel like if the button would be directly under the cap.

So, estimated costs (w/o PCBs and Case/Frontpanel) for a 4x16 BLM: ca. 20 EUR, 8x16 BLM: 40 EUR, 16x16 BLM: 80 EUR

Best Regards, Thorsten.

[sineSurfer]

mmm, I'll have to try it, thanks for the searching/testing TK!

btw. is the Flame Six-in-a-Row using this solution?

[latigid on]

I'm in, but were you thinking about a PCB to make soldering life a little easier?

Of course, these would be "easier":

 b3w_9t1.jpg   4.77K   131 downloads
 switch.jpeg   8.73K   98 downloads

http://www.omron.com...df/en-b3w-9.pdf

, but at ~2.20US each, TK's idea is more affordable

http://mouser.com/Pr...mgJJhoE/NFbUA==

Edit:
Price breaks if interested:

1: $2.68
25: $2.39
50: $2.32
100: $2.20
250: $2.11
500: $1.96
1,000: $1.77

Edited by latigid on, 08 December 2009 - 10:59.

[nILS]

I've been toying around with that approach quite a while back. Worked pretty well and it's a lot more reliable than it would seem at first

[latigid on]

The next question is whether SMD is okay?

RG clear SMD LEDs from Mouser



I tried searching for clear RG LEDs through hole; nothing jumping out at me.

[Intermedi8]

Ive already seen this idea here: http://www.anyma.ch/...inated-buttons/

However, this silicon mat looks very stable? Doesnt it affect other buttons around when u push one?

[TK.]

I'm in, but were you thinking about a PCB to make soldering life a little easier?

Yes, Wilba works on the PCB.

Of course, these would be "easier":

 b3w_9t1.jpg   4.77K   131 downloads
 switch.jpeg   8.73K   98 downloads

I remember that you wrote me a PM concerning these buttons a while ago.
However, they are far too expensive for such a project. You are free to use these buttons though, but I'm not sure if it will be possible to support them by a standard PCB, as the additional drill holes would increase the costs for everybody. You would have to layout your own PCB.

The next question is whether SMD is okay?

RG clear SMD LEDs from Mouser

Nice idea, using SMD wouldn't hurt here (contrariwise, it would be easier to solder them at the top of the PCB).
But they would also increase the distance to the knobs, accordingly the view angle gets wider, and this increases the danger that the LED light of a certain knob is visible on other knobs as well. Therefore common 3 or 5 mm LEDs would be better.

Ive already seen this idea here: http://www.anyma.ch/...inated-buttons/

However, this silicon mat looks very stable? Doesnt it affect other buttons around when u push one?

Thanks for the link!
The silicon material which was proposed by Per is *much* better than a latex glove or those balloons.
Especially the ones with 2mm thickness.

It's for example available here:
http://www.modulor.d...d/AAT/anid/AATD

I purchased the 2,0 x 240 x 500 variant for 9.90 EUR and it will be sufficient for the complete 16x16 BLM + some control buttons/LEDs.

Of course, you have to take care that the buttons are not too close together - it worked at my side with the distance you can see on the pictures above.

Best Regards, Thorsten.

[latigid on]

Of course, the Omron switches are waaaay too expensive.

I realise the SMD LEDs would be too short, but then could lower profile (shorter) tact switches be used as well? Or is the idea to mount other components (e.g. encoders) on the same board?

[Echopraxia]

From seeing your giant 16x16 strip board creation, I have to wonder what your doing right now Any luck with this TK? Looks liek it will be alot of fun. Especially after the solder sickness and carpel tunnel goes away

Would you mind letting us know what strip board brand and size you used to achieve your 16x16 result?

Regards,
echo

[TK.]

It's too early to give you the construction details about this project - first I want to complete it and test the robustness before anybody else starts to build it (or starts with PCB layouts...)

I will create a new webpage once the project is finished.

Best Regards, Thorsten.