Hi!
This is exactly the circuit I already developed. It works with a small microcontroller
and is connected in parallel to the Plus/Minus Buttons of a device.
But not the microcontroller itself controls the plus/minus buttons (as the scanning method
can be different in every synth) so I used analog switched that go in parallel to the buttons.
The biggest problem was that every synth needs other pulse lengths so that on one hand the
pulses and pauses are recogniced and on the other hand a quite fast parameter changing
can take place. As this parameter needs some kind of setup I found a method that is working like
a safe code input:
First you have to enter a combination with the data dial to enter the setup mode and then
you enter the number of milliseconds for the pulse and pause time. So if you enter "20" then you get
20ms pulses and 20ms pauses. And this also means that you can change parameters as fast as
25 steps per second. If you synth scans the matrix faster you can program smaller values.
The setup only needs to be done once for a synth as this value is stored in an EEPROM in the
microcontroller.
And there is a nice little feature that tells you if the programming was successful:
If you enter the safe code when the displayed parameter value on the synth is below (I think it was) 24 then
you see the programmed value at the end of the programming sequence as my software outputs the
programmed number of PLUS keypresses. And this is also the test if the synth can follow the pulse/pause
values without missing some pulses.
The device is very small but the PCB needs some redesign - I need to find some time for it and I need to order some
PCBs and some microcontrollers. But this should be possible in some weeks. I don't know how much it will cost
but if anyone is interested I will let you know. The PCB will be about 25x25mm (1 inch x1 inch).
One of these - I call it "data dials" - is already built into my Kawai K3M - and as it is very small it found a
place on the front of the Kawai K3M ! (left of the Kawai K3M logo and right of the display).
Other synth that will be equipped with the data dial are:
my Poly800, Poly61, Casio CZ101, Crumar Bit01, Crumar Masterkeyboard,...
If I am ready I will make a webpage for it with photos and will tell you how much it would cost.
Ciao
Peter
http://www.ullrich.at.tt________________________________________
Von:
korgpolyex@yahoogroups.com [
korgpolyex@yahoogroups.com] im Auftrag von ASSI [
Stromeko@...]
Gesendet: Samstag, 07. März 2009 11:15
An:
korgpolyex@yahoogroups.comBetreff: Re: [korgpolyex] Parameter increment knob?
On Samstag, 7. März 2009, Alec Jahn wrote:
> Would it be possible to create a simple circuit that would control
> the up/down buttons by a knob? I just have this rough idea of one
> of those infinite "pots" hooked up to an IC that would send out a
> signal replicating the button presses?
Yes, quite certainly. There is a diagram(∗) of the signals put out by
the common incremental encoder types. As long as the button poll rate
is not too low and if the de-bouncing does not ignore narrow pulses,
you could directly fabricate up and down signals with some logic. If
either of these conditions is not met, you would need to do some pulse
conditioning, making them longer or spaced apart or both.
(∗) http://www.ucapps.de/mios/mios_encoder_modes.gif
Achim.
--
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk]>+
SD adaptations for Waldorf Q V3.00R3 and Q+ V3.54R2:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada
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