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Conference napalm::commusic_v1

Title:* * Computer Music, MIDI, and Related Topics * *
Notice:Conference has been write-locked. Use new version.
Moderator:DYPSS1::SCHAFER
Created:Thu Feb 20 1986
Last Modified:Mon Aug 29 1994
Last Successful Update:Fri Jun 06 1997
Number of topics:2852
Total number of notes:33157

2759.0. "Midi solenoid driver? Mechanical SGU?" by BITBKT::FORBES (Bill Forbes - RTI BU) Sun Oct 27 1991 20:44

I have a friend who wants to build a set of chimes - *real* chimes, that is,
not synthesized - and use solenoid-driven hammers to sound them.  He'd like to
use off-the-shelf sequencer software to compose/transpose the music.  (I'm
actually not sure I'm using the term "sequencer" correctly here...someone
please correct me if I'm not.)

Anyway, what my friend is looking for is a sort of "mechanical SGU" - that is,
something that will turn midi protocol into TTL signals for driving solenoids.
I think he would eventually like to build a track organ operated on the same
principle.

Are there any vendors out there who make such a thing?  Seems to me that
someone must make robot fingers for "real" pianos.  And/or a midi interface to
drive them.

Since the emphasis in this conference seems to be on electronic SGUs, I gave
up looking for pertinent notes after about 30 minutes.  Any pointers to
appropriate keywords etc would be appreciated.

Thanks,

Bill
T.RTitleUserPersonal
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2759.1exiMAST::GRUNDMANNBillMon Oct 28 1991 10:062
    I would try to see if PAIA sells this sort of interface.  It seems to
    be right up their alley.
2759.2Musical tree ornaments4GL::DICKSONMon Oct 28 1991 11:2123
    I was thinking that something like this would be a neat way to use
    those musical Christmas tree ornaments that are in the stores this
    year.
    
    The best one I have seen so far costs $80 and consists of a string
    of eight ornaments, with wires between like tree lights.  Each ornament
    is a small drum about 2" in diameter and sitting on top of the drum is
    an elf (and Santa on the last one).  Each elf holds a mallet.  On
    either side of the elf is a small tuned bell.  On command from the
    control box that sits under the tree, each elf can swing left or right
    to hit one of his bells.  So there are a total of 16 notes.
    
    The control box knows 32 songs, probably in ROM.  Up to 4 note harmony,
    according to the box.
    
    It is a neat effect in a store, but in your house the clanging would
    probably get to you after a while.  Hence the desire for a MIDI adaptor
    for this thing.
    
    The wires seem to be twisted pairs to each elf.  Could be a common
    ground, and then a signal wire to each elf.  The bidirectional mallet
    swinging is probably controlled by the polarity of a pulse on the
    signal wire, to an electromagnet in the drum, under the elf.
2759.3SUBSYS::SHERMANTue Oct 29 1991 14:569
    One way (wild guess) is to look at using a MIDI to CV converter.  I
    don't know much about CV, but I assume it is a way to convert MIDI
    pitch events into voltage levels or some such.  That done, you may be
    able to use an AD converter or some such device to create logical
    signals that can then be run through your drivers to tiny relays or
    SCRs that control solenoids.  I'd estimate cost at around $200 for a
    workable system.
    
    Steve
2759.4Willing to wield solder?TOOK::MCPHERSONi'm only 5 foot one...Tue Oct 29 1991 15:1710
    There was a DIY article in EM (remember when they used to print those
    instead of 60 pages of glossy ads??? :^/ )  some time back  (maybe a
    year) that was all about making a MIDI interface for controlling CV or
    other devices...

    If the person is DIY-inclined, answer here and I'll go see if I can dig
    up the issue get a copy of the article to you. (I've still got just
    about every issue dating back into the "Polyphony" days...)

    /doug
2759.5Thanks!BITBKT::FORBESBill Forbes - RTI BUTue Oct 29 1991 19:2413
        Re: <<< Note 2759.4 by TOOK::MCPHERSON "i'm only 5 foot one..." >>>

That would be great, if you could look up the DIY article.  It occurs to me
that a MIDI-to-TTL may *not* be the same as a MIDI-to-CV (digital != analog).
It should be possible to modify a MIDI-to-CV design to make it MIDI-to-TTL at
an even lower cost.

Also, I've contacted PAIA and they're sending me some literature.  I'll post a
description of what they send when I get it.

Thanks for all the replies (so far).

Bill
2759.6Actually, the Ramones have many chords and patternsPENUTS::HNELSONHoyt 275-3407 C/RDB/SQL/X/MotifWed Oct 30 1991 12:517
    I think of this everytime I put on the Ramones. It would be great to
    stand in Harvard Square some summer evening, dressed up as Joey,
    playing those three-four chords, and singing "I Wanna Be Sedated." The
    essential complement to this otherwise-solo act would be a drumbot,
    also Levied and Foster-Granted, pseudo-head banging in rhythm just like
    Marky Ramone. I could teach it both Ramones drum patterns! Solenoid
    city, it would be too cool.
2759.78^)GOES11::G_HOUSETommy The CatWed Oct 30 1991 16:246
    re: .6
    
    Not to be obnoxious or anything, but there are 6 chords in "I Wanna Be
    Sedated"...
    
    Greg
2759.8Yamaha might have them built-inUTROP1::HARTOG_Hdehartog@actrix.enet.dec.comWed Oct 30 1991 18:214
    Doesn't Yamaha have those things built under every key of their
    simple-piano-look piano's that can replay from floppies (and
    you'll see the keys going down!)? Or doesn't the floppy contain
    
2759.9got a soldering iron?SUOSW3::HAMANNThu Oct 31 1991 05:2824
    Hi,
    if I had to control hammers by a midi data stream I would not consider
    a midi to voltage converter.
    
    All you need is a small single board computer or micro controller which
    has a serial input that can be set to 31,2 bits/s and the required
    number of parallel output parts.
    
    The total hardware would be about 100$.
    
    Well, software. You would need assembly programming skills and some
    sort of development system. These things are normaly supplied by
    PCs, but I have a microcontroller with an on board assembler in prom.
    
    So it depends on your experience, if you can get it done.
    
    If you have a PC available and would get along with 8 data lines,
    you could use the serial in port to read midi data and the printer port
    to output your hammer signals. No great business.
    
    enjoy your chimes!
    Klaus
    
     
2759.10Find the article, and then decideBSS::STPALY::MOLLERFix it before it breaksThu Oct 31 1991 14:0518
	The EM article referenced earlier also listed a source of PC board,
	components and a pre-programmed CPU (has the ROM on board). It allowed
	you to choose the MIDI channel that you desired, and it would
	respond to 8 note on/off's (nothing fancy, but certainly usable).
	The output was a transistor which could switch a Relay if need be,
	and pretty much drive anything. I was considering using one for
	control of a lighting system, but this got pushed on a back burner
	because of some other efforts I have in mind - I still want to do it,
	however. If this was what you had in mind, I think that this is
	a good first step. One of the suggested first uses was to MIDI-IZE
	old drum machines that you liked the sound of, but couldn't use
	with your MIDI gear (since this is a trigger system, ie, a slave,
	not a controller). 8 notes is a limitation for a lot of applications,
	but it's certainly a start.

								Jens