Electric Piano Midification

[SIDsyndrome]

Hi All,

I am working on a MB-6582 MIDIbox SID project, and I want to combine it with the midification of an old (non-working) electric piano that I have lying around.  I'm looking for some advice as to how I should approach this, and if it is indeed feasible. 

What I'm working with is a Univox 61-key electric piano type keyboard... It is not a tine piano like a Fender Rhodes... but I'm not exactly sure what the means of tone production is.  I can take pictures soon if that would be helpful, but in the meantime if anyone has any experience with this type of keyboard, I'd love to hear what you have to say.

Thanks,

SIDsyndrome

[SIDsyndrome]

I'm perfectly willing to gut this keyboard and just use the keys of it and whatever simple on/off switching is necessary to send information in the MIDI world... nothing fancy with touch sensitivity or retaining the original electronics is necessary... Any ideas?

Thank you!

[dubstructor]

Hi SIDsyndrome,

that's actually exactly what I'm trying to do with a broken synth I found in a trash bin.

Does your synth have MIDI ports ? Mine have, but sadly they're unusable because of some issue with the synth µcontrollers. However, would they work, I thought about two different solutions :

- sending synth MIDI out to your PIC Tx pin, via optocoupler and so on, then somehow programming your PIC for turning the incoming midi messages into something readable by the device you're attempting to control  .... but this would assume a rather unusual connecting scheme, where your PIC would send midi to another device than the one it receives midi from, and I wouldn't advice it (unless someone more reliable than me in this domain says the contrary ....).

Clearlier (I hope ...) :

    basic scheme :

    control surface -> DIN/AIN/... -> PIC) -> MIDI out -> (controlled device

                                                      ) <- MIDI in    <- (

    modified scheme :

   

    your synth ) -> MIDI out ----------> PIC) -> MIDI out ------------------------> (controlled device

                    ) <- MIDI in left unused]        ) <- no MIDI in from controlled device]  (

DON'T TRY THIS unless someone-who-knows tells you to do, it might lead to your pic destruction. BTW, it will prevent you from doing the loopback tests if you're not already sure your core is properly working.

Here comes the second solution :

first ensure that the MIDI messages are the ones you want, typically note on/off, by midi-plugging your synth directly on any device that can show you the messages actually sent, like a pc with miosstudio.

Then, go to the merger page to see how you can merge your midibox and your synth messages. AFAIK, this will probably be achieved by using a second PIC (well, if I understood well, you can use the same PIC for both merging and your application, depending on your programming skills, but this could dramatically slow down its performances.)

///////////////////////////////////////////////////////////////////////////////////////////////

OR you don't have midi ports, or don't want to use them. Time to play the screwpull and meter. You have to disassemble the keyboard from your synth, then see :

- how it was connected ;

- how is its inner circuitry designed ;

- what happens when one or more keys are played (the previous step normally already gave you at least a clue for that).

For instance, it appeared that mine basically works as a scan-matrix. What about yours ?

One more time, I precise that I have good basic electronics skills, but the world of PICs is still a step beyond that I haven't reached yet. If you're planning on using your keyboard as a standalone MIDI device for controlling your SID, then wait for wiser advices. If you're hoping to use it only as a control surface directly talking to your PIC w/o any midi in-between, then you have to understand how the keyboard works. I'm only sharing my ideas because we're on the same ship.

Hope that helps.

Peace, Dubs.

   

[SIDsyndrome]

Thanks so much, dubstructor! 

The electric piano I have is pre-MIDI and has no MIDI connections of any type whatsoever.  I won't be able to look any further into the way the keys work yet until I get back from vacation, so I'll have an update in about a week.

[dubstructor]

OK so now we definitely ARE on the same board  ;)

I'll make my experiments with midibox kb this week-end.

BTW, maybe you can have a look on a datasheet for your synth ?

Good holidays!

Peace, Dubs .