Sparkfun silicon duo matrix

Design Concepts
1

Ok, several have asked about my progress on this, and thanks to Ultra for the image hosting, I will post my current progress on making the duo matrix with these sexy SparkFun silicon buttons:  http://www.sparkfun.com/commerce/product_info.php?products_id=7835

The duo matrix is currently used only in MB-SEQ (schematic here: http://www.ucapps.de/mbhp/button_duoled_matrix.pdf) but I see many more possibilities for it…

First up the buttons themselves in their just opened at Christmas state:

I also ordered some of the SparkFun PCBs thinking I could add SMD diodes but then decided to go another way…

Here’s some tests with bi-color led lit with 5 vdc and 150 ohm resistor:

The hot spots are not quite as prominent as the photo’s suggest.

They do seem plenty bright, but when powered by scan matrix, they may not be.

More to come…

2

Next the meat of my concept, I use SMD components to make a 4x8 panel, with all shift registers on board.  This allows the pcb to be tiled either right to left or top to bottom.  This way with two boards I can make either the 4x16 MB-Seq duo matrix, or an 8x8 monome like control.  With the interconnects being only serial, the usual spaghetti mess should be eliminated.

But first thing is that the MB-Seq duo matrix design needs improvement.  As TK points out in his comment “CIRCUIT NEEDS TO BE IMPROVED FOR HIGH CURRENT LEDS!” the DEFAULT_SRM_DOUT_CATHODES<n> shift registers are sinking way more current than they can handle.  In the seq the extreme case is 9 leds at once and should be rare.  But for general case max is 16 leds, and with these lighting through silicon buttons, each will require more current than TKs.  According to my calcs, and tests run by SmashTV seem to concur, the source shift registers should be able to supply >18 mA per pin with all firing. So for first stab at improving the circuit I added current sinking transistors to the led pins on each DEFAULT_SRM_DOUT_CATHODES<n> shift register:

NOTE: this requires inversion of those pins of the shift register in the seq software…

3

… no funny presents in the box from Boulder - Colorado ?

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Next the pcbs, which I ordered from Gold Phoenix:

One test subject on the slab:

Did i mention this was my first SMD project??

32 fargin diodes, 10 fargin resistors, 4 fargin caps, 4 fargin sr, 2 res packs etc later:

32 bi-color leds later ahhh through-hole, like a cool spring breeze…

next the testing…

5

akkk doesn’t work at first, too many leds lit up, core won’t boot etc etc ahhhhhhh

ok calm down, remove transistors, try again

akkk core boots, but buttons don’t work.

don’t take torch to pcb!

did I mention I tried to hack together a test program from seq code? 

too much in there…

brain weakening…

losing consiousness…

ok screw it, use the sm-simple example pgm.  It will work without the leds connected…

ok now we get somewhere, found some solder bridges etc.

did i mention this was my first smd project?

the test rig:

evidence of buttons working (or clever hacking *whack*)

ok hacked sm-simple to handle one row of leds (was simpler that way) and connected one transistor:

a bit dim for sunlight viewing but look at it in the dark:

next let’s see all them leds lit up.

to be continued…

6

excellent! More motivation to break ground on my seq

7

looks good.  we want kit :stuck_out_tongue:

8

perdy lights!

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ok, several soldering errors (did i mention this is my first smd project?)

and several software bugs later, we have all buttons/leds working in test program.

had to kludge it a bit, but it’s ok for testing.

in the dark:

Here i changed the duty cycle to 1/4 (the sm_simple program uses 1/8)

which brightened things up considerably:

and, as my adoring fans have come to expect, the dark shot:

next i need to build out a second brd and change the software to handle both sides.

also there is some amount of instability in these buttons.  some buttons take a large

amount of force to react, and there is a good deal of “bouncing.”  i will look into debounce and

also cleaning and treating the pads on the board, it may be that (as SmashTV strongly

suggests) ENIG is the only way to go…

10

Dude, X-L-ent design, but why not go eight way color on the LEDs?

My thought is to set up a 24x64 button psionic matrix and stream video via an RGB+sync and DC Restore.

Sting used a setup like this for part of the recent Police tour, but greater potential exists.

Also, from your photos I can tell you are a Starbucks junkie (welcome to the club!), you own an iPhone,

you are into German cars, you use Hammermill (that is some stupid bugging paper!), and you are into Hungarian speakers and trepanation.

You got it happening - we should hook up and do a J.

Keep up the good work, and post more pics!

Also, what kind of warranty are you going to offer these with once you get your proto running?

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and now the whole banana 8x8:

and the money shot (in the dark):

stripping the HASL plating makes the buttons very responsive.

i ordered some cool-amp (thanks cimo and SmashTV)

which plates bare copper with silver to protect it.

but ENIG is definitely the way to go if any new brds are made.

the sm_simple app has no debouncing which will be necessary

with these buttons so i will be working on that in the example app

and also cleaning the code up for public consumption. 

also there are a few other strangenesses i need to work out…

12

Electroless Nickle Immersion Gold is the bumpity bomb.

We at work get all up in underneath with that and get our prefab on and what not.

Unfortunate that we are not yet feeling the debouncing love.

Again, consider going 8 way on the colors - it really causes  event horizon to pop.

Also, that is some mighty fine wood grain you are sporting on that table.  8)

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13

Dude, X-L-ent design, but why not go eight way color on the LEDs?

because, as you well know, that would take an extra shift register per brd, and a

more difficult routing effort (which was already tough enough).  besides, 3 colors

ought to be enough for anybody. what are ya gonna do, watch tv on it?

My thought is to set up a 24x64 button psionic matrix and stream video via an RGB+sync and DC Restore.

Sting used a setup like this for part of the recent Police tour, but greater potential exists.

you go, girl!

Also, from your photos I can tell you are a Starbucks junkie (welcome to the club!)

indeed!

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Hey do you think if we strap rockets to it, we can break the land speed record? ;D

16

MC Cacasentenze, looks like you are on the wrong track - this is a DIY community, you are free to modify what you are offered here  ;D. And “offered” is not meant in the sense of you pay you get something… more like: you get some recipe, modify it and give back your recipe. THAT would make you a valuable member.

Best regards, ilmenator

17

..can i also use james nipply nipples pic for my account ? after all i ve been a long time fan club subscriber of the guitar throwing idol / nipples whipper .. uh?

and then why not adding ultraviolet and infrared leds ? you can get tanned and talk to extraterrestrian while MBing !

18

…this is a DIY community…

yep, most you can hope for is a run of pcbs for this.

speaking of, just testing the water here, no promises.

let’s gauge the interest in a pcb run.

is anybody interested at all?

19

..can i also use james nipply nipples pic for my account ? after all i ve been a long time fan club subscriber of the guitar throwing idol / nipples whipper .. uh?

uh oh, mc, you’ve been outed.  where’d you get that photo???

and then why not adding ultraviolet and infrared leds ? you can get tanned and talk to extraterrestrian while MBing !

mmmmm maybe even better than led porn (the dark shot)

but i don’t need leds to talk to extraterrestrials…

20

I’d love to get in on a PCB order for these.  They look amazing.