Digital pots?

[chrisw]

So i was looking on wiki pedia and found they have digitial pots well since on midi fighters you can expand the controller. 4 digital inputs well can you use digital rotary pots?

[Filterkat]

So i was looking on wiki pedia and found they have digitial pots well since on midi fighters you can expand the controller. 4 digital inputs well can you use digital rotary pots?

in theory you could... but i think 1 rotary pot would take up 2 digital inputs on the board if my reasearch is correct... but technicallly yes... this also means they could be endless rotarys

You can also route pots to the "analogue" inputs of the board... but since its midi... theres not much thats analogue about it... this is definately confirmed (just look at the custom midi fighter controllers on the store... boy do they look nice) but i am not sure as to wheter or not they can be endless. i think in this respect its rather the traditional 4 oclock 8 oclock setup like the EQ's on your mixer

you can also add faders, additional buttons... hell if your good enough with electronics you could add a touch sensitive ribbon controller, a touch sensitive X/Y pad... Just depends on how good you are with electronics...

i have a mate that made a midi box (mind you hes an electrician) out of PBC plastic, with 6 touch sensitive ribbon controllers, 21 "analogue" knobs, 6 digital knobs and 12 buttons with a midi crossfader which he uses with ableton... Hes planning on adding an X/Y pad to it... Plus hes got a midi fighter... lol

[Str8upDrew]

Digital pots are not physical controllers. Meaning they are controlled digitally, not with a knob.

[Filterkat]

Digital pots are not physical controllers. Meaning they are controlled digitally, not with a knob.

Sorry mate im going to have to disagree with you on that... yes they are controlled digitally... and sure... you can have a digital pot without an actual physical knob if you wanted (which would be quite pointless unless you designed some kind of software/firmware which could display the position of the digital pot, and then you would need some way to manipulate the pot... and still)

But a digital pot uses a small chip circut to function rather than an analogue circut... But theres nothing stopping you from routing/wiring a PHYSICAL pot to control the "digital pot"s paramaters.

This is what i was saying about the "endless rotary" theory... most, nearly all endless rotaries are "digital pots" since an analogue pot usually has a predetermined, limited range, usually the 4/8 oclock standard...


IN SHORT:
a digital pot uses a chip to decode values/send information (wether it has a physical pot routed to it or not)

where as an analogue pot uses resistors to modulate the current passing through the pot thus NEEDING a physical "knob" to manipulate the values

[Str8upDrew]

I can see where you might be confused. A digital pot doesn't really "use" a small chip to function, it is the small chip. A potentiometer is just a variable state resistor, and all it does is limit the current flowing through the circuit. Now a rotary encoder sends out a digitally coded signal: some kinds use alternating waveforms/pulses, others use a binary style. I can see how this may be confusing since a pot and rotary encoder look similar, but the signals they process are very different.
Here's a pic of a digital pot...


Now some digital pot's do use a push button interface, but most are SPI, I2c, and so on.
Here's some more info about a digital pot that i've used in the past...
http://www.analog.com/en/digital-to-...s/product.html
http://www.analog.com/static/importe...ets/AD5220.pdf

[Filterkat]

i understand what you are saying completely... i am not confused in anyway... i understand how electrical circutry works and i have built both analogue circuts and chip based circuts... i understand that the digital pot is the chip itself... i know that an analogue potentiometer and a digital rotary encoder have entirely different signals/functionality... but im just saying, it would be kind of useless to have a digital pot without some kind of rotary knob or interface to control its paramaters with...

it would kind of be like having the latest car motor sitting in your garage, with no actual car to drive it with...