[LAU] Control surfaces - whats already available

[Fons Adriaensen]

On Sat, Jul 05, 2014 at 10:17:21AM -0700, Len Ovens wrote:
 
> I do want to try the rotary encoder though. either with a large
> wheel (actually 2-3inch is not that big) or belt with no LED strip.
> The on screen fader position should be good enough.

In case you'd consider the motorised fader, there's an Arduino
project using it:

http://blog.codyhazelwood.me/motorized-faders-and-the-arduino/

There's one problem with this: the author has the H-bridge
'enable' pin hardwired. This means that the motor always
sees a low-impedance voltage source. The voltage can be
zero, but that will make the motor resist movement.

When the fader is 'touched', the motor should be open-circuit,
so the H-bridge should be disabled, this takes one more pin on
the controller.

You could actually control the 'resistance' of the fader
by pulse-width modulating the enable pins of the bridge.

To control many faders you'd need some external logic to
multiplex the Arduino's logic pins, but otherwise everything
is there.

Ciao,

 
-- 
FA

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