ComputerVoltageSources

As John has mentioned, you can't 'or' MIDI input data.  You have to 
parse it to commands, convert running status back to full commands, 
and interleave new MIDI data.  It requires another pair of hardware 
serial ports.  The smaller AVR processors only have 1 pair.  You could 
go to a larger part with 2 pairs of serial hardware or you could 
simply add another AT2313.  The parts are cheap and there is no 
'logical' connection between the LCD/MIDI out data and MIDI in.

I have actually used an AtomPro24 to do this very function (my MIDI 
bass pedals scans 13 keys and merges them with MIDI data).  I just 
implemented the key switches as notes on and off instead of sysex 
commands.  I have also written most of this code for an AVR so it 
would be easy to add.

Several thoughts.

First, anyone could add an off-board MIDI processor.  I can probably 
be talked into writing the code.  It's just two wires, power, and 
reset so it could easily be added.

However, some other thoughts (wild and crazy).  I have a MIDI command 
parser written for the AtomPro24 already.  I have used it to implement 
specific hardware commands.  For example, if you have an 88 note MIDI 
keyboard, you never use the high and low notes (at least I don't).  
Use them as input keys.

Another option is to use a pitch-bend with no keys depressed. This can 
turn your entire keyboard into an input device.  Pitch-bend again 
with no notes depressed to 'return' to normal MIDI mode.

I actually use MIDI keyboards as input to PSIM programs that don't use 
MIDI.  It's just a way of getting many more digital inputs. You can 
use a low note on + pitch wheel as another analog input to select or 
scroll through selections.  So much is possible once you have the 
ability to parse the MIDI data stream.  It may not be the most 
friendly user interface but it works.

Dave


--- In ComputerVoltageSources@yahoogroups.com, "John Loffink" 
<jloffink@...> wrote:
>
> Doc,
> 
> No problem making the suggestion.  A free flow of ideas is good.  
Here are a
> couple of considerations that I see:
> 
> 1.  Dave has already allocated all pins of the ATtiny2313.  We'd 
need a
> larger ATMEGA device for the button inputs.
> 2.  MIDI RX at the CVS board can't be easily shared, or OR'd as 
suggested,
> unless you have a toggle to turn external MIDI on/off or insure MIDI 
IN is
> not used.  So MIDI from the LCD Support PCB to the CVS PCB requires 
another
> dedicated pin on the BASIC ATOM PRO.
> 3.  Need a cursor character for button data entry, which consumes 
one of the
> programmable LCD characters.
> 4.  Program or parameter selection can also be done from the CVS 
knobs, if
> so desired.  Maybe one knob scrolls through functions, another 
changes the
> values.  This makes buttons redundant, but dedicates the knobs to 
that
> function.
> 5.  Data entry is really valuable if we have runtime Flash storage, 
which we
> apparently get with the ATOM PRO 28M.  
> 
> John Loffink
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com
> The Wavemakers Synthesizer Web Site
> http://www.wavemakers-synth.com
> 
> 
> > -----Original Message-----
> > From: ComputerVoltageSources@yahoogroups.com
> > [mailto:ComputerVoltageSources@yahoogroups.com] On Behalf Of 
drmabuce
> > 
> > Hi All (especially John, Dave, Eric & any other LCD enthusiasts)
> > first off,
> > 
> > please feel free to tell me to [insert favorite euphemism for 
consume
> > feces and cease to exist here] because i lack the expertise and 
the
> > time to pitch in on this suggestion in any substantive way....
> > 
> > it's a fair cop...
> > 
> > but here goes
> > 
> > i've been trying to digest all the discussion about the LCD
> > implementation and my (so-called) mind wandered into the question 
of
> > using this gadget not only as a display but as part of an INPUT 
scheme
> >  for user interaction as well.
> > (yes! i know i've always been sort of indifferent to the LCD 
before
> > and so i have to wear the 'hypocrite hat' for 24 hours too!)
> > 
> > 
> > 
> > ------------
> > but considering the following two design ideas:
> > 
> > a separate (Samsung? Hitachi?) microcontroller residing on a 
separate
> >   PCB with the LCD
> > 
> > and
> > 
> > a fairly flexible and open-ended interface, specifically: 
piggybacking
> > display data traffic on MIDI sysex
> > (which strikes me as cleverer every time i think about it... kudos 
Dave!)
> > -------
> > 
> > Is it feasible and practical to consider the addition of a few 
(maybe
> > 5) buttons to interact with the display via cursor? (up down left
> > right  enter)
> > and THUS transmit some data to the main CSV processor (ie program
> > selection parameter select etc.) via sysex
> > Now as i have already expressed my readiness to be openly 
ridiculed
> > for broaching such a can of worms. Let me say that i have a little
> > experience with the software side of interpreting 'Keyhole' 
interfaces
> >  and i realize that as a user interface, they are far from 
luxurious
> > (ala the DX7 or the Mirage)
> > 
> > i also realize that we'd have to "OR" into the RXD pin on the Main
> > processor but that doesn't 'SEEM' to intrusive to my unschooled 
eye.
> > 
> > so i'll shut up about this now
> > and leave this notion to those better able to judge it's merits 
than
> > myself
> > 
> > a tip of the hat to all for keeping this barn-raising in motion,
> > -doc
> >
>