qwerty project

Design Concepts
1

I’m new here in the forums so an Hello!  :wink: is in order for all of you.

second, since i’m new here i dont know if this is the right section, if not, i would like to apologise in advance for my n00bness

third, i have a project i would like to develop, but i’m also completely new to diy electronics (closest i haver got was lego technic)

that for me is the big problem, being a n00b on the subject, i tried to read somethings online but i only get more confused…

the project is in fact simple (i think…) i want a trigger box (much like http://www.m-audio.com/products/en_us/TriggerFinger.html) or a midi keyboard if you will…

i cant get used to my axiom 49 neither with the pads cause they dont have a spring like recoil (so im never sure ifthey worked or not without looking to the screen, nor with the actual keys since i’ve never played piano, they are too big and far apart to trigger vj clips

but as i spent my whole life using computers i get pretty confortable with qwerty keys

the problem with using the qwerty is that he sometimes jams when pressing more then 3\4 keys and start beeeping or not being able to touch an alt-space without minimizing apps, etc…

i want to do a midibox with qwerty keys, and if possible each key led lit on press (either inside the key or out, doesn’t matter much..)

so apart from the obvious “go get a spare qwerty, start dissecting and start building a layout case” where else do i start?

i’m completely in the dark so any help is apreciated

thanks for your time and attention  :wink:

2

Welcome aboard mate :slight_smile: You got the right section of the forum don’t worry!

Lego technic is probably as good a starting point as any. There’s already a C64 keyboard driver around here some place… If you want to use another keyboard, then your solution will depend on the hardware you use, and how you want to use it…

3

thanks for the fast reply  :slight_smile:

you’re talking about this http://www.midibox.org/dokuwiki/midiboxkb_-_using_a_c64_keyboard_as_input right?

if so thanks, i’ll probably write a pm to bill, to see if he can help me out.

tell me just one more thing, because soldering i think its the least complicated part since i paint miniatures so i dont think my fingers are the shakiest ones,

but its the electronic theory and components that worries me even if its a simple project because im completely in the dark, and trying to read the basics with a lot of references to din and pcb and programing references, doesn’t help

do you have any material (docs, videos) explaining midi basics to noobs in both midi and electronics, like basic components in a 1 key midibox, what must be connected to what, who sends signal to whom, and how to make home made pcb (from the little i understood thats the term for those green boards sorry if i’m mistaken) stuff like that, that probably i should know about before nagging anyone to help me with this box.

to put it simply “stupidproof electronic and midi basics”

4

Yeh that’s the one…

Most of what you want to know, you’ll find by searching google, these forums, the wiki, and ucapps.de. Have a solid read of all that, and let us know if you see any ‘gaps’ that we can help with :slight_smile:

5

can you at least point me to where can be a good place to start?

6

Hey Werlin,

I’ve been around here for a bit but still consider myself a bit noobish. I will tell you now that if you really need some help you are going to have to demonstrate to people here that you have done your reading. However the link you have provided contains all the info you need. I know because I have followed those same instructions and was able to get the keyboard working np.

You will need to get the parts. I would suggest going to SMASHTV’s website and buying a core kit and LCD at least, If you bought a din and dout kit, and some ribbon cable/headers you would have everything major you need to get this project going. You might even be able to work out a special order with smash for just the parts you need but I don’t know too much about that.

You would want an LCD for testing, look around here for all the info you need to pick the right one.

Here is the link to smash’s store

http://www.avishowtech.com/mbhp/buy.html

Everyone buys from him and he is very professional.

Good luck with the keyboard. Not only might you find it is useful for your needs but also that if you get the c64 for cheap you get a cheap case with lots of buttons for your controller but also a free SID chip for your next project :wink:

Have fun

Lief

7

Sounds Like you have chosen an ambitious first project.

Good for you!

I will offer the following thoughts on the subject:

You are wandering into at least three different areas all at once.

You wish to learn more about MIDI,

You wish to learn more about electronics,

You need to know something about how PC keyboards work.

If you are willing to stick with it, this project can be done, and there are people here who will help you along the way. But you must understand that it will take time, study, and patience if you want to pull it all together. If you expect to be finished with this project in a few days, you will fail. I think a reasonable guess would be a few weeks to a few months, if you stick to it. Your time will be well spent, and at the end, you will have a device of your own design and a great deal of new knowledge.

Now, you asked for more information.

To learn more about how MIDI works, I like this site:  http://home.roadrunner.com/~jgglatt/

Click “Technical Documents and Programming”, then “The MIDI Standard”

Read all you can, then read it again. It’s an incredibly complete site.

About electronics, I’m not sure where to send you. It really depends on how much you know already. Lief has it right, build a core, DIN, DOUT, and LCD display. Those can be purchased as kits. Once they are built, study the schematics and if you don’t understand something, ask questions. The real “magic” comes when you can see the links between hardware and software, and better understand the big picture. Playing with DIN and DOUT modules will get you much closer to that “Aha!” moment.

Finally, you can follow the 64 keyboard project for ideas (I have not looked at that yet), Or you can hack the keyboard keys to a DIN module, either discrete or in a matrix, or if you want a more “standard” keyboard, you might go study the PS2 keyboard protocols, and try programming your own. That would give you the choice of hundreds of inexpensive keyboards to choose from. That kind of information is best found with a tool like Google. Try “PIC PS2 keyboard”

Have fun, but understand that it will not happen overnight.

LyleHaze

8

can you at least point me to where can be a good place to start?

Maybe it doesn’t seem that way, but I just did.

For example, if you search the forum for newbies links, and visit the wiki, you’ll quickly find sites like the one lyle linked, and www.play-hookey.com, and http://publications.gbdirect.co.uk/c_book/

9

that is what i was talking about some basics, gone from nowhere to a store some basic midi concepts and some C (kind of hoped never to touch it again, but looks that when you “speak digital” there’s no way around it (took some basics of that and pascal in highschool, my grades were good but was so freaking anoying it slaped me back to arts near the end, and maybe i’ll call in a friend or two to see if i can dodge that bullet))

but thanks i’ll do some reading starting with the midi basics, the qwerty basics and then the c page as painfull as it may be, and i wouldn’t say this weakend but maybe next week i’ll have to bug you guys, pick your brain some more if you’re up to it, to see if i can make some sense out of this.

a big thanks to all of you  :wink:

10

that is what i was talking about

Those were just examples. Do the searching!

11

and so i did, today i dedicated myself to start to learn a bit about the first order of business: to know more about what i am converting, the ps2 keyboard

learned about keyboard types i didnt even knew in terms of layout(qwerty,dvorak, wich is irrelevant to this) and key types itself : membrane  metal and dome switches. picking up the later, wich are the type i want to convert, rubber dome switches function with a matrix circuit underneat, the whole multiplexing process that allows to figure out what key is pressed by a column\row system that allows the processing unit to calculate in what point the matrix sufered an electric disturbance.

so here’s my firt question:

can that circuit matrix for the dome-switches be made at home?

and if so can anyone who has already made it provide me with some docs?

because i dont find nothing on the subject… in the instructables and other sites with various keyboard conversions and mods, they all use the circuit that already comes with the original keyboard, wich for this is a problem since i dont really want the key alignment all croocked, i wanted only to reuse the cubic keys(and respective switches), like the letters, numbers, f1-12 etc, and design 4 separate sections of (4*5) 20 keys each.

wich brings me to my second question, (just as a layout curiosity, since i havent yet read the midi part of the subject) about one thing i saw in bill’s post i think, that is the fact of the midi operation system, the mios, being able to deal with 8*8 matrixes wich only allow a maximum of 64 keys, so:

is this the maximum of triggers i’ll be able to put and actively use in only one device?  can the mios handle bigger matrixes in order to have 4 sections of 20 keys, 80 total, in the same matrix? or even if only supports 8*8 matrixes but can it handle 2 of those at the same time, 40 keys in each?

12

re:making keys.

Most modern PC keyboards today have the key making contact with pads on the circuit board. I would guess this is not the easiest thing to re-make on your own.

Looking for complete keyswitches at some parts supplier (maybe Digi-Key or Mouser in the USA) will give you the flexibility to layout your own key patterns without having to actually “make” each keyswitch. If the legs on the keyswitch are spaced on a 0.1" matrix, you can even use perfboard to make up your switch panel.

You might look at some of the buttons that others around here are using. There was even a few threads about adding your own lighting under the caps of some button types.

re:Matrices

I have no experience with doing switch matrices in MIOS yet.

Have Fun,

LyleHaze

13

can that circuit matrix for the dome-switches be made at home?

I’d start with veroboard/protoboard/whatever you call it.

14

im not talking about this-> http://werlintm.no.sapo.pt/DSC00167.JPG

i’m talking about this circuit -> http://werlintm.no.sapo.pt/DSC00168.JPG

altough they are both in fact elect. circuits the one i’m talking about, not only is printed in polypropylene but the scale its a little bigger than normal pcb for standart components, and altough it connect with normal pcb’s at the circuits end, due to the scale factor, i dont see how i can test the rubber domes interacting with a normal small protoboard

btw i already dl electronics for dummies and eletronic projects for dummies, but i’m gonna see if i can find them in paper cause reading 400 pages off a monitor… ???

also about the polypropylene circuits i’m gonna go and try to find someone that can custom print them, and also see in wich format they need the file to be done, so i can find an app to make it, and also read the midi part before i print anything so i dont end up with to many keyspaces if the mios cant handle them…

15

If I understand correctly…

Those flexible printed circuit boards you refer to, are probably going to cost a lot. You would also need a custom made frame for the keys. It would be significantly cheaper to buy a normal keyboard and mod it, than have it custom made. You can also get the same effect by using a normal pcb (like your first pic) and using keyboard switches. There is no difference in the size of the keys, and you can put them on protoboard which you can buy in large sizes.

Alternately, do you already have a keyboard to use? If it has the same connector ‘tab’ on the edge as the one in your picture, then you can buy a socket for that, and connect it to the MBHP modules.

16

http://home.roadrunner.com/~jgglatt/hardware/pc_keys/adapter.htm

I saw this on one of the links, I don’t really understand it, but it looks like what you are describing.

17

Sweet, PS/2 to midi. Nice find Paul.

Unfortunately werlin said he didn’t want to use PS/2 because he thinks it locks up on too many held keys… which it shouldn’t do really, but it does sometimes… but maybe the AVR will handle multiple held keys better than a PC driver (where such a thing would be unnecessary)

18

@stryd_one

by reading with a little bit more attention the 1st article i read about dome switches the other day, i think there’s a way around the problem…

apparently (i say apparently because i presently dont have another keyboard here to open for a better inspection, and i’m not about to dissect the one beneath my fingers, that has helped me trough many paragraphs such as this) there are at least two types of rubber-dome switches:

the one that i dissected from which i showed you the flexible pcb, that has in fact two separate circuits in two sheets and a middle sheet with holes right below the domes that allow the two circuits to connect simply by pressing the rubber forcing the contact point of the top circuit to stretch just enough to reach the bottom circuit

as for the second type, -as the article in the wikipedia about keyboard technology says- there is graphite to make the conection between the two terminals (a fact that i found strange, the absence of graphite, when i opened the keyboard but which i quickly dismissed)

whether they are still separate circuits separated by a mid-sheet, its still beyond me… but if not, and if in fact can be done in a normal pcb, all i will have to do is go search for a keyboard with dome switches with graphite, and i can make a new re-arranged pcb…

as for a custom made case, its not gonna be that expensive : i know someone  :stuck_out_tongue:

@ paul_winterhater

thanks 4 the link i will surely check it out more closely, but besides the locked keys argument, i also want to redesign the whole layout of the keys, also if i’m not mistaken that link deals with the conversion to a midi synth (and i maybe on the stupid path here, because i haven’t read about the midi part of the subject, so forgive me) not to a midi general controller for triggering videos in vj apps

so for now all i have to do is wait for tomorrow to see about the flexible pcb’s, wich i couldnt get done since the weekend got in the way of trying to reach the stores to know who prints them, if anyone in this god forsaken country…

i’ll check my hunch about the alternative for that, to search for a keyboard more alike with the one in that wiki picture above

and right this instant i’m gonna get back to my electronics for dummies (it really is stupid proof… well almost  8) i should have had more attention in the electricity module at school)

19

Why the fixation on flexible circuits/custom made cases (which will still be expensive even if you do know someone)?

20

its not the flexible circuits, i know they must be expensive, and as i explained i’m gonna see if there’s a way around them (altough i have tought of trying to make a trigger\fader\knob sleeve somewhere in the future after this project, in which a flex-circuit would reveal it self handy)

its the custom layout that will cost me next to nothing, so i’m gonna go for it if its possible