n0zem

finger trigger zendrum

10 posts in this topic

Okay back again, last project is still in the fridge but will come out after this one i think.

What i want to make is a zen drum like finger trigger drum midi controller. I first looked here and didn´t find anything so i looked around a little further and found the megadrum project learned a lot and came back here again cause without the sourcecode.. Well its like comparing lego with playmobil when you have a boat in playmobil it stays that a boat forever and you can`t even make it bigger :-).

So looked around here again and my idea is to make something like the midibox 64. with 40 analog inputs where i can attach my triggers. Gladly i found in the sourcecode from the midibox 64 that there is already played around with drum triggers so i just have to finetune the programming there (i have no c programming expierence so i am glad there is already a starting point).

but my questions

1. to use piezo`s as triggers i have to control the input voltage. The analog board from dmitri (megadrum) uses bat85 diodes connected to ground and 5v to regulate this. I don`t want to put 80 diodes on my input board can i use diode arrays like http://www.reichelt.de/BY-BYX-EM-ER-Dioden/DAN-803/3/index.html?;ACTION=3;LA=446;ARTICLE=95223;GROUPID=2989;artnr=DAN+803;SID=10T9UAn38AAAIAAFfhPjQ9a6c81e9e4b5b284cf333ee13f700443 instead (i know i need 2 directions)

2. I would like to integrate the usb interface from megadrum shouldn`t be a problem i think, but when i use the usb as vcc input can it affect the functioning of the midibox? I dont know how the 4051`s calculate their output but i can imagine that when vcc is 4v that it is louder when i play soft.

3. can i use the 18F4520 (its cheaper than the 18f452)

4. has anyone played around with the drumtrigger code in the midibox64 i would like to hear how it works.

Niels

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1. If all of the cathodes in dmitri's schematic connect to a common pin and the other technical parameters are the same then yes.

2. The USB port should always give you 5V, so why would you expect VCC to be 4V?

3. No, and in single quantities the difference in cost is negligible.

4. Not me, sorry!

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Thanx

1. as far as i understand will this work. Not that i`m sure it`s realy neccesary i made a test trigger last night and okay a multimeter is perhaps not the most accurate to measure voltage from a piezo but i didn`t get it higher than 0,5 v and okay it goes down to -0,2 well think i put them in just to be sure. a shame they don`t sell the 4851 in dip in germany.

2. Just reading the specs of usb it can drop down to 4v when you put a long cable on it, but i now checked all components musn`t be a problem.

3. 20% is not negligible :) all just a way of perception but than i will order the 18f4620 it`s still cheaper than the 18f452 ..... a whole 45 cents :-) and you get more for less.

4 :-)

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3. 20% is not negligible :) all just a way of perception but than i will order the 18f4620 it`s still cheaper than the 18f452 ..... a whole 45 cents :-) and you get more for less.

Your mistake is that you are only making reference to the processor's cost, when in fact you need to relate it to the overall cost of the project. Then, it will be in the lower one-digit region - if at all - and hence it's negligible. :whistle:

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Why ya want to use megadrum-components in general when your final goal is a midibox!?

PIC-Core and AIN-module(s), or, as ya said ya want usb a.s.o, LPC17 and AINSER64, job done! ,-)

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I got almost everything for the PIC version at home for my Midibox SID project wich was in the fridge the last two years (i just need the pic and the components for the ain module (when i calulate now ist still 3% :-p ) Also i know nothing about elektronics and i like to understand what i`m doing this is easier with the pic version when i understand this.

The adaptions from megadrum are just some extra components on the ain module to protect the 4051 from voltage fluxes wich could be to high or to low.

As for USB i don`t know if i integrate this. But for the Pic version i could get me the gm5 usb which has an smd on it. I want to build the whole thing on vectorboard dont know perhaps looks like crap but that way i realy have to plan and understand the conections. With the USB solution on the Megadrum site i can use an PIC 18f2450 which is cheap and i can integrate it on an vectorboard okay i dont have the control but it should be stable.

I`m now halfway my pic burner and that already takes a lot of time with al the stuff you got to learn (wich pin is what on almost all components.) I´m not complaining (having way to much fun with this stuff) but it`s definitly more complex than my cigar box guitars :-)

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Core on VB can be pain in the ass, buy some PCBs from mike, best way for first-time-bilders in my opinion.

The big advance to build it with dedicated PCBs is, apart from easier soldering, that ya can use the modules for different layouts / projects, just make the ins/outs with either pinstrips or sockets.

So ya can easy quick-prototype several new ideas to decide if it worth to build it full or not! :-)

Edit: Wenn noch fragen sind frag einfach, ich kann auch deutsch! ,-)

Edited by Brathering

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Danke Brathering Deutsch ist aber auch nicht meine Muttersprache werde ich also genau soviele fehler machen :) (mache ich aber in Niederländisch auch)

Wenn ich richtig festlaufe kann ich zum gluck Rio fragen der wohnt hier nur 10 km weiter.

I know PCB´s is probably easier, but i`m a bit stubborn I like to do it on vectorboard and i know i will manage :)

My first circuit worked (just the voltage regulation part of the pic burner) Worked because i was not carefull enough and invented the LER (light emitting resistor) still got to work a little on lifespan i guess.

Just glad i still have got to order the pic and parts for the ain module a few more components are negligible. :whistle:

i will post some pics of the casebuilding process soon.

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okay forget this my computer was spinning and didn`t show the last sent message

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I've quit trying to do it on VB, the time would required for it I use now to etch a PCB and be sure that every connection is right - but good luck with it! :-)

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