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
> >
>