Ask Slashdot: Physical Input Devices For Developers?

First time accepted submitter paysonwelch writes "I am a developer and entrepreneur and I am considering developing a very graphically rich and custom interface for my latest application which does charting and analysis of large data sets. The application would feature lots of gauges, knobs and levers. As I was thinking about this I said to myself, why not hook up physical knobs and levers to my computer to control my application instead of designing them in 2D bitmaps? This could potentially save screen space and provide tactile feedback, and a new way of interacting digitally with one's application and data. So my question is whether or not anyone out there has advice for building a custom solution, perhaps starting with a mixing board, or if there are any pre-fab kits / controllers for achieving this?"

midi faders

[TheGratefulNet]

lots of dials and knobs via midi boxes.

sound cards used to be able to import midi control data.

alternately, if you are into diy, arduino for the pure hardware interface and then send serial rs232 data up to the host (via usb but its still serial inside). you can read knobs via the a/d pins on the arduino and you can read buttons via port expanders or local pins.

USB MIDI controllers

[LikwidCirkel]

Electronic musicians have been demanding high-quality tactile interfaces for many years. There are various USB MIDI controllers on the marked with various arrangements of knobs, buttons, keys and other moving things. Check out M-Audio and Alesis and other big names, and you might get some good ideas.

tons of choices out there

[OttoErotic]

X-Keys [piengineering.com] or Monome [monome.org] or any one of a million Control Surfaces [google.com], for starters. Or Arduino obviously. Personally I think that for a lot of applications the best solution is to drop the knobs and switches, take apart an old USB keyboard, and build a custom button-based interface using the matrix board. Interface it with hotkeys built into your app, and this way it shows up as a regular HID without needing specialty drivers.

Existing Products:

[Walwark]

People who use software for music production like tactile controllers as well. There's a range of products out there from the korg nanokontrol (~59US) series up to the euphonix line (~1000US+). Most nowadays use USB and older ones tend to use MIDI. Motorized knobs are hard to come by in this market, but lots of products use LED rings to provide visual feedback since the encoder is endless. Motorized faders on the other hand (is this a lever? lol) are rather plentiful and not too expensive. Start your search with "control surfaces" and possibly some other terms like 'DAW' or 'MIDI' or 'USB'

What you want...

[fuzzyfuzzyfungus]

The electronic music/DAW/DJ crowd has been all over this sort of stuff for some years.

Something like the Aurora [auroramixer.com] is an open source hardware example; but there are a large number of devices at various price points and levels of openness that boil down to a whole bunch of knobs, buttons, and sliders, with some sort of computer-compatible interface(often MIDI or USB-MIDI device, sometimes with a driver or plugin for Ableton or Max specific to the device).

The audio guys may not map 100% to your requirements; but they have the advantage of being a reasonably large, reasonably active, community with a fair amount of existing hardware available off the shelf.

As an alternative, many contemporary microcontrollers are capable of serving as USB slaves. Something like a teensy [pjrc.com] is pretty cheap and makes it dead easy to turn inputs from buttons and sliders and rotary encoders and things into USB HID keycodes.

Like a USB knob?

[Anothermouse Cowered]

http://www.trossenrobotics.com/p/phidgets-encoder.aspx?feed=Froogle [trossenrobotics.com]

Re:USB MIDI controllers

[iluvcapra]

Note well before going down this route: MIDI controllers are optimized for very good time resolution and fast response, but a MIDI continuous controller like a knob will generally only have 7 bits of resolution. Some controllers offer better but the message format isn't always standard. I use the 2-octave keyboard version of a Novation ZERO SL Mk 2 [novationmusic.com], this has plenty of buttons, long faders, and detentless soft-knobs: set up a MIDI router and you're off.

If you have an iPad you can also design your own knob/fader/button/X-Y pad interfaces with an OSC client [hexler.net], OSC controls aren't limited to 7 bits and there are plenty of libraries and utilities for handling OSC messages.

Start with this

[RedLeg]

Griffin Powermate. Been around a while, affordable.

http://store.griffintechnology.com/powermate-1 [griffintechnology.com]

Let the net do your shopping to save $bucks.

Lots more out there, this has easy interface via USB.

Red

Space Navigator

[Rhalin]

http://www.3dconnexion.com/products/spacepilot-pro.html [3dconnexion.com]

Probably not exactly what your looking for, but its top notch hardware with a reasonably nice SDK. Depending on exactly what your app does, the multiple axiseses of control might also be beneficial.

Re:Have some experience here

[iluvcapra]

Something cool about the Behringer BCF is that it has motorized faders, and the fader moves can be controlled through non-proprietary messages, which is pretty unusual and awesome. The fader legends on the BCF are null in the middle, because they're meant to be used for organ drawbars and parameter automation, so that makes them a bit more generalist than regular flying faders, which usually null toward the top.

Also, the BCF gives you an EXPRESSION PEDAL input! Don't knock it till you try it, gives you two hands free for controlling a continuous parameter. I've used an expression pedal to control shuttle speed on a video playback.

Re:Have some experience here

[NormalVisual]

I will go one step further and recommend the submitter visit Musician's Friend [musiciansfriend.com] or Sweetwater Sound [sweetwater.com] and check out any of a number of MIDI control surfaces. I am happy a few people have had good luck with Behringer gear, but based on my own experience I refuse to let another piece of it in my home. I can't speak regarding their MIDI gear, but their mixing/recording gear *sucks* - they can't design proper power supplies to save their lives, and in general their gear is designed with low cost as THE primary driving factor and IMO it can sometimes be a fire hazard. It's great fun when you fire up a mixer and smoke rolls out of the power supply, and then you open it up and find that the voltage regulators they used in the supply were rated for about half the current they needed to handle. I bought a Behringer patch bay thinking, "there's no way they could screw THAT up". I was wrong. Plastic parts where metal was needed, and low quality 1/4" jacks throughout.

I'd go with a more upscale manufacturer such as Korg, Yamaha, Roland, etc., or if it has to be low-cost, M-audio is not too bad.

Re:Human Factors

[walshy007]

Since you say this is for personal interest, I shall link you to what I use for sliders/knobs.

This [soundonsound.com] is rather useful. 30 knobs, 9 sliders, many buttons and doubles as a fully weighted piano. Whole thing is powered over usb bus and I picked mine up on special for $450. usb midi compliant so no drivers required, works nicely with whatever midi subsystem your os uses.

Trouble these days would be finding one, production stopped some years ago.

Programming wise midi support is probably the best way to go with this, large support for varying hardware much of which has knobs and sliders.