[sdiy] MIDI VOL PEDAL with no micro??

[Scott Gravenhorst]

Dan Snazelle <subjectivity at hotmail.com> wrote:
>what would be the best book on this sort of detailed information 
>on reading/ sending midi messages and midi hardware ? 
>
>i have a penfold book on the subject but i bought that years ago 
>and its pretty surface... it basically shows you how to make a 
>midi patchbay. 
>
>
>thanks

I dunno about a book, I just use the MIDI spec for information regarding what to send.


>
>
>
>> On Feb 8, 2014, at 3:00 PM, "Scott Gravenhorst" <music.maker at gte.net> wrote:
>> 
>> 
>> Dan Snazelle <subjectivity at hotmail.com> wrote:
>>> thanks for the practical advice!!
>>> 
>>> 
>>> ive made midi things with an avr before and other than trying to 
>>> get my friend comfortable with learning some code ( or pasting 
>>> some) i think its the easiest way to go 
>>> 
>>> 
>>> just what exactly would you do with shift registers, and a ADC... 
>>> in other words, the CC message, if you wanted to make a CC #1 
>>> pedal...would it just be the same conversion to 1's and 0's over 
>>> and over??
>> 
>> The ADC could be a bit of work too if done all in CMOS.  It would work the same way it
>> would work in an AVR, yes, a loop that gets the ADC value (converted from the pot) and
>> constructs the CC #1 message (3 bytes if you ignore running status).
>> 
>>> 
>>> i wonder ( from the bending angle) if you could get any good 
>>> results from sending sporadic bursts of 8 bit digital information 
>>> via an opto to a synth?
>> 
>> The data needs to be structured into MIDI messages.  You could simplify slightly by not
>> using running status - then you'd always send 3 byte messages.  In that case if you sent
>> random data as the third byte (forcing bit 7 to zero), you would then be sending a CC
>> message at some regular interval with a databyte that is random 
>from 0 thru 127. Dunno how > useful that would be, probably 
>depends on the user. > > >> >> Sent from my iPhone >> >>> On Feb 
>8, 2014, at 2:30 PM, "Scott Gravenhorst" <music.maker at gte.net> 
>wrote: >>> >>> >>> Dan Snazelle <subjectivity at hotmail.com> wrote: 
>>>>> is it possible to create a MIDI volume pedal with nothing 
>but an >>>> optocoupler, opamps, cmos and passives? >>>> >>>> 
>>>>> i ask because i have a friend who wants to make one himself 
>>>>> >>>> id just use an AVR with an opto and a pot based 
>pedal.... but i >>>> thought it might be fun to go the other 
>route >>>> >>>> >>>> are CC messages complex? i wouldnt dare try 
>this with SYSEX but i >>>> thought a CC pedal might be within the 
>realm of possibility! >>>> >>>> >>>> thanks >>> >>> I'd use the 
>AVR or a PIC. But yes, with enough CMOS parts you could >>> make 
>a state machine that could handle it. However, you'll need to add 
>>>> a UART and bit clock (unless you want to build that out of 
>CMOS too). >>> In my view, the complexity is enough to warrant a 
>uProc. Think of all >>> the things the uProc would have to do - 
>all of that would have to be >>> represented in CMOS logic. > > 
>-- ScottG > 
>________________________________________________________________________ 
>> -- Scott Gravenhorst > -- FPGA MIDI Synth Info: 
>jovianpyx.dyndns.org:8080/public/FPGA_synth/ > -- FatMan Mods 
>Etc.: jovianpyx.dyndns.org:8080/public/fatman/ > -- Some Random 
>Electronics Bits: jovianpyx.dyndns.org:8080/public/electronics/ > 
>-- When the going gets tough, the tough use the command line. > 
>-- Matt 21:22 > > _______________________________________________ 
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>

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synth Info: jovianpyx.dyndns.org:8080/public/FPGA_synth/
-- FatMan Mods Etc.: jovianpyx.dyndns.org:8080/public/fatman/
-- Some Random Electronics Bits: jovianpyx.dyndns.org:8080/public/electronics/
-- When the going gets tough, the tough use the command line.
-- Matt 21:22