bpm controller

86 posts in this topic

Posted · Report post

well as i dont want to hijack the other guys thread i will start this one here.

i have got my bpm software and i love it, only issue no dedicated controller, so after a little reading i thought why not build one using the pads and contacts from an akai mpc unit or rip a korg nano open which would be cheaper! and use an mb64e to make this.

so after a little read up i think thats the way im will go.

so this is whats going to be needed

17 rotary encoders + 17 metal top knobs

1 jog wheel and potentiometer + jog cap

8 small factor 10k linear faders

33 momentary buttons

akai mpc 4x4 pads giving a need for a further 16 "buttons" so to speak.

instead of the little display that the software version shows, i could fit a midimon in there and a mtc display also.

so ok i understand i would need two cores one for the midimon and one for the mb64e side.

so i think, however i hope to be corrected i will need the following

2 x cores

2 x doutx

3 x dinx4

1 x bankstick to store setups

1 x psu

each dial and fader or button would be able to transmit its own midi cc/id and be set up in the editor if possible? and then i can map it to the virtual bpm via digital performers assign via midi input or map via midi.

or is it better to use the mb64 rather than the 64e?

any advice gratefully recieved before i start.

that lot to make this basically

bpm1.jpg

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Posted · Report post

sorted.

i spoke with smash and i have got it all alid out now, so i know what i need, just a little wait for the right pic to come into stock for smashy.

so the build will entail, if i can remember rightly...

for the mb64e:

1 core pic 452

2 dinx modules for the faders, buttons and encoders- regarding the encoders do i use endless encoders or not? i know that they need to be 24 ppr encoders.

now if im using an lcd with this which i will do i need an AIN module?

and then another midimon kit which is the core, doutx and other bits i know of from my current build of one.

i also need an endless encoder and a jog wheel for it as well. anyone got any suggestions for this?

thanks again to smash for his help. beers on me ;)

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Posted · Report post

found a supplier for all my rotaries and faders also for the jog wheel, i have to thank another member for the heads up on the jog wheel thanks to D2K for the website http://www2.okw.com/okw/index1.asp for the info on the jog wheel encoders, i have found the exact one i want there, called them today and its on the way.

thanks to nils for the heads up on the small form faders the manufacturer of the ones i want also does the fader caps too.

spoke with my cnc company today and they will make the casework for me with lead time of 7-10 days.

waiting to hear from the mpc guys about getting the right zif connector for the pad sensors, i know molex have a range of them but i need to know pitch etc for them to get the correct one.

last but not least the wife says i can do my order with smash this week , when she decides to give me my money but only as much as i need so i dont go on another shopping spree.

once again this place has proved invaluable with its help from its members.

this is going to be a really enjoyable build !!

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Posted · Report post

I am a newbie so dont take what I say as gospel, but I am pretty certain you won't need anything special to use an LCD....for the mbSID they connect directly to the core so id assume it will be the same for this. Looks like a sweet project bro :) looking forward to seeing how it ends up

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Posted · Report post

thanks unrise.

well reading things again it seems i dont need the ain module after all, i wasnt sure and really needed to know , but a little more reading witha clear head and im sure i dont.

well i showed the picture of the virtual pad to the cnc place and they said no problems, they can even laser engrave the lettering for me as well., all i have to do is supply them with the drawings from solidworks and the fonts when ready.

so i guess i need to build it all first then get the case sorted out!

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Posted · Report post

Some general hints that can be time and money savers:

* when you lay out the CS (which you prolly do first) always use a grid (preferrably 100mil as that's what you'd have on veroboard [make sure to align the pins of the components]) , that'll make it soo much easier to not mess up spacing/positioning between the panel and the CS pcb(s)

* when you think you like the layout, print it out 1:1, put it in front of yourself, put the knobs and buttons on it (if you got em already) and pretend to work with it - this helps a lot to make sure the spacing and positioning is good

* do show some layouts, maybe someone has a good idea or sees sth that you overlooked - happens to me all the time

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Posted · Report post

thanks nils.

i was doing 1:1 printouts the other day for the buttons and leds for m-mon controller, so i will be doing a 1:1 print out anyway, but it will be on a real nice thick stiff card.

its going to be about the same size as an akai mpc unit when its finished. im hoping the guys in the states can give me the dimensions of the pads before they arrive. otherwise i have to wait until it all does.

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Posted · Report post

quick question because im need to make sure.

the mb64e is happy for me to use 10k encoders and 10k 60mm faders for this? or should i se different rated ones as there is nothing specific about which ratings are best to use with the mb64e

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Posted · Report post

There is no such thing as a "10k encoder" ;) just use one of the regular/recommended types from Smash, Voti, Alps etc.  Faders should be 10k linear.

S

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Posted · Report post

Potentiometers (if that's what you meant with 10k encoders) should be 10k linear as well :-)

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Posted · Report post

ok well i finally found what i needed to read up on things, had to look elsewhere to find the info on adifferent page but i got it in the end this does not include the lcd for the mb64e here or the midimon stuff yet, i will add that later on.

layout.jpg

now the pdfs show say using 4 din4x boards that im looking at 16 encoders and 32 buttons per din4x board. now then i will need 25 encoders 7 of which will be 60mm 10k linear faders non motorised in place of a rotary encoder and i will then want 53 buttons.

i have figured the layout now but i have a question.

can i mix faders and buttons on a din4x boards connections?say i used 5 of the terminals for buttons and the remaining two for encoders is that ok?

apart from that theres no other questions really i have taken the 8 buttons needed for the mbe64 lcd and the 4 for the midimon lcd i will also fit in as well.

took a little looking around with a heads up from smashtv to let me know to use the din4x rather than the ain board once i knew that what i needed was on the din page, it might be a good idea to have some of the din4x pdfs on the mb64e pages as well as they are relevent to that design, as i spent ages reading and looking through that page to find the info i needed.

i will add some of my stuff as pdf to that page as well if its wanted.

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Posted · Report post

Looks sweet. a really nice project.

There is some confusion about encoders, pots and sliders..

An encoder is a knob that can turn endlessly without reaching stops. An encoder connects to a DIN board and uses two inputs. Normally all the encoders are grouped together.

A pot is a knob that has stops. It is a resistor with a sliding tap point. These are measured in Ohms, or more likely Kilo-Ohms (thousands of ohms, or just K). Each pot requires one analog input(AIN).

A slider is a pot that goes in a straight line, not a knob turning. It also requires an AIN input

Pots and sliders can be "scaled" to be linear (even distribution) or Log (tapered to match our hearing).

So if you're using pots or sliders you might want to watch that. Usually volume controls are LOG and other controls are linear.

When you speak of

i will need 25 encoders 7 of which will be 60mm 10k linear faders non motorised in place of a rotary encoder and i will then want 53 buttons.

I get confused. encoders and 10K linear faders are different creatures..

you may be able to change the software to replace one with another, but you cannot connect the 10K faders or pots to a DIN board. These will require some sort of analog input to work.

Or maybe it's me that's confused. This is very possible. :-)

Ouch.. It's too early in the morning to be thinking.

LyleHaze

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Posted · Report post

hi lylehaze.

its probaly me thats at fault, the mb64e section is sparse in information really i had to goto the din board section to get more info.

i dont know whats possible or not thats why i put the schematic change up and explained what i wanted, i will need 7 60mm faders in there somehow. im sure the 64e uses encoders instead of pots, anyway right now just when i thought i had a clue about things i dont again, looks like another days reading and trying to make sense of going back and fore in pages and pdfsok is it possible to use these faders instead as they are linear encoders same as used in behringers.

http://www.infiniumtechnologies.com/categories/20090619

60mm i want

http://www.infiniumtechnologies.com/downloads/20090617_2/download

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Posted · Report post

I was wrong.. You taught me something today.

Those really are linear encoders!

Bad news, the "regular" encoder inputs to the MBox expect what is called "Quadrature encoder" signals. That's just two square waves that are 90 degrees out of phase.

The device you showed me offers a choice of: UART, SPI, or Analog.

You can teach a PIC to read any of those, but none match the "regular" encoder inputs we are ready for now.

UART is a serial port..

SPI is "Serial Peripheral Interface", kinda like I2C but different. there MAY be a SPI driver in MIOS..??

Analog would attach to an AIN module (oh, now were back THERE again.)

The other choice, (not so bad really) would be to add a small extra PIC just to translate UART or SPI into quadrature signals for MIOS. Sounds crazy, but it might be the easiest way to open the door for these cool faders.

As always, I might be wrong with all of this. I've been wrong once today already. :-)

Maybe a MIOS GURU can tell us if MIOS does SPI.

Still, very cool faders!

Good Luck,

LyleHaze

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Posted · Report post

thanks lyle.

well i have put up a once and for all answer thread in the parts questions section of the forum because i have spent the best part of two days getting nowhere and im getting a little bit more than peed off now.

i do not want to have to fit an ain board to this, surely the din4x board will take 7 faders amoungst everything else in there??

i am really hoping that thorsten will pop in and give a definative answer to this quandry because i cant remember if someones told me in chat, or if its a yes or no, or if theres a pdf or anything, because once i know im going to add it to the wiki and do a pdf schematic to add to the mb64e section because i dont want anyoneelse to get as frustrated as i have become, but then again im so fuzzed up on medication now i can rmember things when they are in front of me.

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Posted · Report post

Ikea,

Sorry you're having a rough time with this.

I hope my comments are helping and not making it more difficult.

I'm really _not_ trying to give you a hard time.

I will offer one more suggestion:

Because you are asking about a very specific part, it would really help you to get solid answers if you post the link to the datasheet of the part you want to use. Until I read that sheet I was sure that I was right and you were wrong. Once I read it I gained a whole different perspective. :-)

In any case, good luck sorting this, and I'll help if I can.

Maybe I'll be helpful and post that datasheet for you.. if I can figure out how.

Us hardware types are pretty dangerous with URL's, you know.

Good Luck,

LyleHaze

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Posted · Report post

lyle no problems mate, its a real bad day for me today i havent slept properly for two days and my head is full of schematics and asm code and other stuff inbetween puking.

im trying to figure this out myself and its getting really frustrating now.i have scoured the net for linear encoders and im not getting anywhere past infinitys ones.

time out for me.

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Posted · Report post

all is going good with this project, i have now got all the switches i needwith all the button caps required, also many thanks to wilba for selling me some spare lcd's and a load of rotary encoders. today i laid out the components on the desk to see an approximate size of it and its not too bad, i have to work out placement on a few things when i get the knobs and i can bring things a little closer together.

plan is now to combine the mb64e in there as the main controller unit along with a midimon unit and have it all controlled via a usb gm5 unit running midi using the digital terminals as per my hu-mon build.

so as of yet the next parts to get are the two cores, 4 dinx and an ain also a dout board and some small form 4digit 7segment leds

power will come from a 9.5v psu that delivers 2.5a so that should be enough for both units i hope.

i will add some pictures later of the layout. right now im back to solidworks and loads of technical parts drawings and building the casework.

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Posted · Report post

well i started working layouts tonight here is the first one of many to come on a 1:1 scale, i havenbt figured out the mtc layout yet either, it would be so nice if i could fit a larger graphical display in there and have the midimon and the mb64e stuff on one screen.

100_2188.jpg

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Posted · Report post

things are looking good for the bpm unit now, i have all the switches and knobs i need know , so all that remains is to order the kits i need from smashtv.

so if anyone here knows anyway i can get paypal to fix my damn account for me, let me know because its driving me nuts now not being able to use it.

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productive few days now, i have finally got paypal working again and paid for my kits from smashtv also a new set of sensors and pads from mpcstuff to use as the drum pads. all that will be winging its way here soon.

this week i have spent learning eagle the hard way, also spending some much needed time having a few pointer lessons with nils over the internet using the showmypc software, a boon for a quick practical demonstration!!!

today i managed to make a correctly dimensioned library object for eagle of the  soundwell encoders that wilba did the group buys on, so if anyone wants it let me know. tonight i am doing the 8 pin mec switches i have got. the main reason for this is i can then make an all in one baord for the rotaries and switches, and learn etching in the process.

i have to be honest i didnt think i would get this far along in such a short amount of time, so many thanks to the guys here, especially nils who has spent so much time advising me, im going to make this thread as detaild as i can as i go along, also i will give the full casework dxf/dwg solidworks or iges files to twin-x to add here permenently so everyone can download them and get them made also and use the project as a generic mpc style controller, myself personally i want o make an exact replica of the bpm, and with the find of a nice slimline external usb dvd drive and a few other bits its going to look like the original exactly apart from the big graphical interface, however this will be replaced by a 20x4 lcd for the midimon i will put inside with a small factor 7segment mtc display and below that the 20x2 for the mb64e display.

i have to say i am seriously excited about this one as it will be a real credit to everyone whos helped me the past few months to get it really nice.

needless to say i will be getting the case work professionally laser cut and cnc bent again like the hu-mon, and then i will get the legends silkscreened onto the case.

more to follow over the next few weeks.

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Posted · Report post

ok i got my replacement pads and pad sensors however i have a quandry.

the sensor array uses fsr force resistive sensor harder i press less resistive it gets, now how can i use these as momentaries on my dinx boards????? because i do not have a clue how!

this page i have found from an old pdf from a company that used to make them for akai mpc's shows some sort of circuit that makes one  some form of switch but would i really have to make a seperate board just for this? there must be a simple way to use them?

(update this looks like a good option for using them prehaps?) http://www.active-robots.com/products/phidgets/datasheets/1121.pdf

any suggestions welcome thanks!

5587_f736c17823355893502d2c98282fe142e87

5587_f736c17823355893502d2c98282fe142e87

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Posted · Report post

OK, I'll take a stab at this, but it comes with a "disclaimer":

Digital (TTL) circuits expect all signals to be "high" or "low", with as little time in between as possible.

Digital(CMOS) circuits are more tolerant of analog voltages, but I don't know how well they will like being permanently in analog mode. at a minimum, I would expect higher current draw, and possibly erratic behavior near the boundaries of high and low.. 

Now, what all that said, I'll proceed.

It looks like the DIN modules use 74HC165 chips. these are CMOS, so far, so good. Each input is already "pulled up" to +5 volts by a 10K resistor. When nothing else is acting on it, you'll "see" 5 volts at the input, meaning "button not pushed".

The datasheet says the guaranteed maximum voltage for a "low" input is about 1/3 VCC. If we already have 10K pullup, then we need a resistance LOWER than 5K pulling to GROUND to get the input that low.

If your sensors reliably go below 5K when pressed, and above 20K when released, then hook them up just like a push button and see what happens!

Worst case is that the 74HC165 chips eventually overheat, and can be replaced for under a buck each.

I can get deeper into the math of voltage dividers if you want.. but only if I am asked to.

Have Fun,

LyleHaze

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Posted · Report post

thanks lyle, lucem gave me some info in chat also.

i recently spoke with the gentleman who actually invented the fsr technology, he was most helpful and very nice to talk to.

i ahve sent him lots of pictures and information on what im building and about the forum and ucapps site.

im hoping that he will be able to tell me what the impedance is soon and i can go from there.

it will be great if i can use these pads on the bpm controller im building, otherwise i would have spent almost $100 on something i cant use!! and i would then have to make a momentary button matrix and sit it under the rubber pads. but space the buttons just under the pads so that they dont depress until you actually give the pads a good press.

thanks again lyle.

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Posted · Report post

If you need to adapt them, I would be happy to provide a circuit.

Have Fun,

LyleHaze

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