[sdiy] Keyboard scanner

[Neil Johnson]

Hi all,

As part of my Siel Opera 6 project I am designing a 61-key keyboard  
scanner module, based on an Atmel ATmega8.  It scans all 61 keys via  
an external 74LS154 decoder and diode matrix (already present on the  
existing contacts board), measures the time-of-flight, and works out  
note-on velocity and note-off velocity.  It also handles pitch-bend  
wheel, modulation wheel, expression pedal and sustain pedal analogue  
inputs.  The intention is that it will talk to a master processor via  
SPI (100kbps should be fast enough).

If this board were to be used for other projects it would be useful  
if the 74LS154 was also on the scanner PCB, together with a suitably  
larger connector (probably 26-pin IDC header).  This would  
necessitate a larger board than a dedicated one for my project.

I figure this project might also be useful to others, perhaps those  
building their own keyboards.  How much interest would there be?  If  
you would find such a board useful then please email me off-list and  
if there is enough interest I'll extend the design accordingly.

Cheers,
Neil
--
http://www.njohnson.co.uk