Music synthesizer from old keyboard

[Electronics4you]

Hi there,

I have searched the web for a music synthesizer controlled from microcontroller or computer from e.g. a serial connection, but nothing useful appeared - so I have decided to make one myself.

My plan is to use an old keyboard (not the PC-type), rip off the keys and make some sort of electronically controlled switch to emulate a keystroke.

However, I don't know exactly how the keys are detected. Can anyone give me some clues how to approach such a project? Is it a matter of simply controlling the current over the key (if they are made in the same way as a computer keyboard) with a simple transistor circuit?

Any answers are appreciated

 

[alec_t]

I have searched the web for a music synthesizer controlled from microcontroller or computer from e.g. a serial connection, but nothing useful appeared

I'm surprised you found nothing. Modern keyboards are synthesisers and nearly all (except the cheapest) have a MIDI interface enabling them to be controlled from a PC or micro. Try researching MIDI (which is a serial protocol).
Many music keyboards provide velocity sensing, so it's not "a matter of simply controlling the current over the key".

 

[Electronics4you]

Well, it may turn out to be an easier choice to just purchase a MIDI keyboard, but that is not nearly as fun as building one myself.
I'll take your comment into consideration. Thanks

 

[Sinedup]

Hi Electronics4you. I have a complete circuit of a simple touch-sensitive midi keyboard scanner buried somewhere in my boxes of paperwork. Many centuries back, a technician friend gave me a hand-drawn sketch that he had made (built his own). When I dig this sketch out, I'll draw it neatly in CAD, then submit it to the forum. Still have to learn how to safely attach an image and other media - my antivirus by default blocks visitors trying to access my hard-disk content. Maybe staff members can advise? Expect few days to about 1 week for Midi circuit. Cheers.

 

[granddad]

E4Y you have chosen a great project , but it depends how much musicality you want to achieve , a simple scan of the keyboard switches will produce a key map , that could be decoded into midi stream of notes-on .. or notes off , giving a fully polyphonic system... I did this some time ago with a PIC16F877 midifying an Elka organ. as the 125khz midi baud fits easily with a 20mhz clock but scanning say 66 keys you only have a few uSec to decode the output and scan again its all about timing..., I solved this and used a pair of mcu with a parallel port connection .( modern mcu at 70MIPS would be solve this issue ) But midi has a lot of control functions to be taken care of ... you really need to include the note velocity ,( time for key to travel ), I did not do this but just had a global setting for all keys.... I fed the midi stream into a Yamaha TG100 XG midi voice box ... shame I wasn't very good at playing !!!

 

[atferrari]

Hi Electronics4you. I have a complete circuit of a simple touch-sensitive midi keyboard scanner buried somewhere in my boxes of paperwork. Many centuries back, a technician friend gave me a hand-drawn sketch that he had made (built his own). When I dig this sketch out, I'll draw it neatly in CAD, then submit it to the forum. Still have to learn how to safely attach an image and other media - my antivirus by default blocks visitors trying to access my hard-disk content. Maybe staff members can advise? Expect few days to about 1 week for Midi circuit. Cheers.

When you are composing a post, the option "Upload a file" is right there on your left just below the line you are typing. Think more and type/talk less.

 

[AnalogKid]

Think more and type/talk less.

Be more moderate and "moderate" less.

ak

 

[Sinedup]

yup

 

[prprog]

Hi Electronics4you. I have a complete circuit of a simple touch-sensitive midi keyboard scanner buried somewhere in my boxes of paperwork. Many centuries back, a technician friend gave me a hand-drawn sketch that he had made (built his own). When I dig this sketch out, I'll draw it neatly in CAD, then submit it to the forum. Still have to learn how to safely attach an image and other media - my antivirus by default blocks visitors trying to access my hard-disk content. Maybe staff members can advise? Expect few days to about 1 week for Midi circuit. Cheers.

I will like to to see the circuit. I built MIDI controllers as a hobby.
Thanks,
PRPROG