Hello, I’d like to build a SEQ V3 with the 64 LED matrix, but am not entirely sure about the specs I should be paying attention to. Would I be able to just build a SEQ v2 with the new PIC and have the capability to add the matrix of I/O buttons/LEDS into it?
Also, do you guys recommend three lead LEDs and do you have a recommended source for them.
Sorry, I tried to read all I could but there isn’t much on the V3 and I’d like the 4x16 matrix (or even more, can it do even more than that?).
PS I am prepared to build a SEQ with:
1 DOUTX4
3 DINX4
1 MBHP_CORE
44 buttons
17 encoders
33 LEDs
So I guess I’d need at least 2 more DOUTs for the increase in LEDs? Would I also need two more DINs?
Keep searching mate, I’m pretty sure all these questions have been answered 
Okay, I’ve looked through everything so here’s my question.
http://www.ucapps.de/mbhp/button_duoled_matrix.pdf
The text in the pdf implies there’s 8 or so resistors (the cathodes number at 8) but in the picture below there appears to be no less than 50.
http://www.midibox.org/midibox_seq_blm_ext/
Also how does this affect the other components. It says you need 2 DIN and 6 DOUT registers, i appears as if they are put directly on the board in the above photograph, so… do you still need other DIN and DOUT for the SEQ v3 or will that many (2 and 6) be enough for the entire module (and then all you need is the CORE)??
Has someone improved the circuit as Thorsten has suggested?
What is the limit of the LED power before I have to change the resistors? Does anything that says “superbright” mean I should lower the resistance?
Will the following parts list (plus CORE and LCDs etc) be enough to make a DuoLED module?
[tt]74HC595 6 511-M74HC595
74HC165 2 511-M74HC165
IC-Sockets for ICs 8 571-3902614
Dual LEDs 64
Momentary Push-Buttons 64
Diode 1N4148 " 64 78-1N4148
Resistor 220 Ohm " 32 291-220K-RC
Resistor 150 Ohm " 32 291-150K-RC[/tt]
which leds and switches for them are you looking at? i’m currently trying to figure out what my seq panel will look like and knowing how much space for the leds and what to use is part of that. i tried the method where you glue a led to the top of a tact switch and it works pretty well. i bet a three-legged led would work even better because you could bend one the opposite way and give it more stability.
i’m doing this as rack mounted (after much deliberation) and i figured it to be 5U high.
which leds and switches for them are you looking at? i’m currently trying to figure out what my seq panel will look like and knowing how much space for the leds and what to use is part of that. i tried the method where you glue a led to the top of a tact switch and it works pretty well. i bet a three-legged led would work even better because you could bend one the opposite way and give it more stability.
i’m doing this as rack mounted (after much deliberation) and i figured it to be 5U high.
Follow my second link, whomever did that panel indeed used 3-leggers and they look fairly even. I’m kind of far back in terms of the planning, I want a dense panel that somehow fits everything together pretty tightly. Mostly because I am anticipating a panel in the future with 32 steps (who knows)! I was thinking of making silicon buttons out of a small ice-cube tray but then the panel would have to be fairly large, and I’m not sure how sensitive my broad buttons would be. If I made silicon buttons I guess I’d just have to put the LEDs side-ways somehow so they’re lower than the button itself.
LEDs are a real mystery to me, dual colors seem expensive and the selection is really huge. I guess if I go silicon I could get two post LEDs? I here you just have to reverse the current and the other color lights? Anyhow I’ll go with whatever is cheaper; I can’t go really extravagant. I’m trying to figure out the cheapest or easiest knobs and LEDs and buttons and I’ll be pretty much set to order from Mouser. Where’d you get those parts for your SEQ?
Rack mountable is cute I guess. mine will be rack mountable, but only because I have a good supply of rack-mountable cases from my work (aluminum). My seq panel will be on the side however so it’s not really going to ever be mounted on a rack. I do however have a perfectly rack-mountable network drive, made from xboxes. I work in telecom and … 5Us is a lot!
Okay, seriously I thought that I was asking some pretty informed questions. If they’re too dumb than I apologize, but I’ve really gone through all the SEQ posts (even tried linking to some to show that).
Is the DUO-LED setup just onboard DINs and DOUTs?
In saying that then why does there not seem to be any capacitors in either the DIN or DOUT chip?
Is there just resistors for the DOUT in this (as there is usually resistors for DIN)? Because it looks like the 10k DIN resistors aren’t included.
I’m really having trouble as the resistors appear to have been taken for granted (and also modified).
i’ve been researching a little more, but a lot of your questions i can’t yet answer.
here is the pdf for the led matrix, if you haven’t found it
http://www.ucapps.de/mbhp/button_duoled_matrix.pdf
edit: i just realized that was your first link. lol.
i do not know about two color leds, but on ebay a company sells three color 5mm rgb leds in 50 packs for $10 (+ $10 shipping to u.s. but i’m sure it can be combined if you order 100).
just search “rgb led” on ebay and find the company that has them for $9.99 buy it now. you want the common cathode leds. i don’t know yet if this will increase the number of necessary dout modules. these will probably be the leds i order. i’m just waiting for the seller to get back to me about combining shipping for 100 leds. also i’m still searching for tactile switches that have the same button diameter (not overall diameter) as a 5mm led. with 4 legs per led i figure the switch top should be about the same size. do you know recommended brands of tactile switches besides alps? i think two post leds won’t work because of the way the dout modules work. they would have to have three legs, one being a shared cathode and they would be wired as if they were two seperate leds.
another edit: i got information somewhere that said to use common cathode leds. for rgb that would mean four legs total, but looking at those pictures, there’s three legs. there’s also three colors to the leds, meaning i’m back to square 1 on finding them!
after playing around a bit with front panel designer, i think i can easily fit the led switch matrix in a 3u panel with room to spare. in fact, i may try to shift it all left and incorporate the magic midi delay as well, if being able to save a setup gets implemented.
i used to want a desktop seq, but i’m also in the works of planning other projects and i figure a rack would be the way to go. i got a 12U rack that can sit on my desk for around $30 at sweetwater. it’s probably cheap but good enough for me.
Okay, seriously I thought that I was asking some pretty informed questions. If they’re too dumb than I apologize, but I’ve really gone through all the SEQ posts (even tried linking to some to show that).
From your postings it’s difficult for me to find out, which ones of the previous questions are already answered.
Is the DUO-LED setup just onboard DINs and DOUTs?
First of all I want to highlight, that the DUO-LED solution was intended as some nice fun for myself, I never thought that anybody else really wants to spend the same soldering effort (it took some days).
After I got unexpected requests from users, who wanted to build the same (unbelievable in my eyes ;-)) I created this schematic in the hope, that somebody else creates a PCB layout to simplify the construction.
And this is the current state - informations are published, I’ve stopped my own activities in this area in the hope that somebody else continues with this extension, and writes a proper documentation
In saying that then why does there not seem to be any capacitors in either the DIN or DOUT chip?
I soldered the caps at the bottom side of my breadboards
They are very important because of the high power consumption of the LEDs. At least 10 uF should be added in addition to the 100 nF for each 74HC595
Is there just resistors for the DOUT in this (as there is usually resistors for DIN)? Because it looks like the 10k DIN resistors aren’t included.
As you can see in this picture: http://www.midibox.org/midibox_seq_blm_ext/07.jpg, the 10k resistors for the 74HC165 can be seen at the top left corner. There are 16 x 150 Ohm resistors for two 74HC595, and the third 74HC595 has no additional resistor, as this one is not required (LEDs are connected from one DOUT pin to another DOUT pin, and they are not between DOUT and ground) - an additional resistor at the third 74HC595 would only limit the voltage.
I’m really having trouble as the resistors appear to have been taken for granted (and also modified).
I think the best solution would be, if somebody would create a PCB layout for the whole circuit.
Best Regards, Thorsten.
P.S.: I got my Duo-LEDs from Reichelt: LED 5 RG-3
Okay, thanks TK, very helpful, but TWO more questions.
Would 15 uf ceramic caps be good enough for the use? I’m assuming the wiring to these chips are exactly like DINs and DOUTs (except for the missing resistors and the cathode matrix).
So, to make a SEQ, would I need any more modules than a CORE, the panel (with the 2 DIN and 6 DOUT chips) and all its wiring? Because I’m not sure whether I’ll need another DIN/OUT for the encoders or not. Aside from that I think everything is more or less clear.
BTW Ultra you may have a few problems with the RGB leds because Thorston noted that using high-powered LEDs is tricky, and most of the RGBs I saw from the search were 5000 or 8000mcd. But I have no idea really.
yeah as this post develops, i’m realizing that going with multicolor leds is probably beyond my capabilities, being pretty new to electronics. the standard way of using just 16 buttons has been done a hundred times, is well documented, and should be good enough for me. besides, i can always build more in the future :). if a pcb layout ever gets made, i can work with that quite easily :).
i’m using tk’s seq v2 panel as a guide for my own layout. for v3, are there any additional buttons that should be added, given that i’m no longer going with 4x16 buttons and just using 1 row like tk?
I think I’m getting close to figuring it out, as long as TK answers my last few questions and this one:
Can you use electrolytic caps (one directional) caps for the 10uf caps for the 595s?
A common design technique is to use 100 nF and elcaps ( electrolytic capacitor, directional caps) in parallel. It doesn’t matter if these are 10uF, 15uF, 22uF, …
Yes, the requirements for RGB LEDs is too high, this would require additional source and sink drivers, and a software variation which inverts the outputs.
So, to make a SEQ, would I need any more modules than a CORE, the panel (with the 2 DIN and 6 DOUT chips) and all its wiring? Because I’m not sure whether I’ll need another DIN/OUT for the encoders or not. Aside from that I think everything is more or less clear.
You need the additional DIN/DOUT modules which are listed under http://www.ucapps.de/midibox_seq_v2.html (the hardware requirements for MBSEQ V2 are also valid for MBSEQ V3)
Best Regards, Thorsten.
So what you’re saying is that I need a base SEQ with 2 DIN and 6 DOUT, and I then need to add 3 MORE DIN and 6 MORE DOUT. Meaning a total of 5 DIN and 12 DOUT? Because I was trying to make certain that the 3DIN nd 6DOUT on the vector boards counted as the DIN and DOUT boards or were extra. Sorry to ask again but it seems like a lot!
Oh wait, I think I’m confusing the individual chips with the 4-chip board. So I guess they’re adding less than I thought.
Hi Napierzaza,
The base SEQ contains 3 DINx4 and 1 DOUTx4 with the last DINx4 that is half stuffed. In total it translates into 10x 74HC165 and 4x 74HC595 chips.
Maybe give a second look to: http://www.ucapps.de/midibox_seq_v2.html
Best regards,
Lall
That’s very useful, however, I still haven’t been directly told whether the Duo-LED interface negates any DIN or DOUT modules or not! Sorry, I am preparing a large Mouser order and need to know!
Hi,
As mentioned by Ultra:
here is the pdf for the led matrix, if you haven’t found it
As mentioned by TK:
You need the additional DIN/DOUT modules which are listed under http://www.ucapps.de/midibox_seq_v2.html (the hardware requirements for MBSEQ V2 are also valid for MBSEQ V3)
So from these two docs:
for the base SEQ you need 3 DINx4 and 1 DOUTx4 which turns into 10x 74HC165 (not 12 as two are unstuffed) and 4x 74HC595.
for the extension you need as extra 2 DINx1 and 6 DOUTx1 which turns into 2x 74HC165 and 6x 74HC595.
Best regards,
Lall
