[sdiy] Calculator Synth

[Ken Stone]

A 74c923 keyboard decoder chip can look after the scanning of a 4x5 array of
switches, and outputs a binary value. Couple it to a DAC, and you are done.
It even supplies a "trigger" signal when a key is pressed. I think someone
used this as a basis for a set of foor pedals ala Taurus too.

Ken

 
>Most of these keypads have a matrix output... so there are row and
>column
>traces... like a 3 x 4 line array for a 12 position keypad. This is very
>common.
>
>You will have to decode this with some scanning system. Its not really
>very
>hard to do... but what output do you want from the keypad ??? CV... MIDI
>???
>
>Is the sound to be onboard, or is this a controller ???
>
>H^) harry
>
>Prototek wrote:
>
>>    Great suggestions by Dr. Strangelove. I was just browsing through
>> the Digi-Key catalog I received today and spotted some really sweet
>> looking keypads. If you have catalog number "TO12," then go to pages
>> 523 and 524. Does anyone know if any of these would work? I guess the
>> main question is, how would I get those keys to trigger the sounds?
>> I've never worked in the realm of keypads and the like so I welcome
>> any guidance/ideas.
>>
>>                            keep computing,
>>                            proto
>> ------
>> "By pressing down a special key it plays a little melody."
>> Kraftwerk, "Pocket Calculator"
>
>
_______________________________________________________________________
Ken Stone   sasami at blaze.net.au  
Modular Synth <http://www.blaze.net.au/~sasami/synth/>
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Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>