Introducing the Chomp (UPDATED)

…the affordable, bite-sized MIDI box for creative music projects.

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THE KICKSTARTER IS LIVE!

Check it out here.

Okay, well that didn’t go as planned!  But all is not lost.  Read about the next steps here.

Stay tuned! (Updated March 17)

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Code is done!  See the update at the bottom for more info.  You know what that means: we have a fully functioning prototype!

Note: Anything with strikethrough text  has been fixed in the current prototype (above).

What is it?

Often times I find people building custom digital music projects have a really hard time figuring out the easiest, most cost efficient, and practical way to construct their device (just google about it – hundreds of people are having trouble!).  If you have a ton of buttons and switches and want to control software with it, you previously had to learn a programming language like Arduino (and build a complicated circuit) or shell out around $240 to pick up a shoddily made, overly complicated proprietary device.  The Chomp is the first affordable, easy to use MIDI controller platform for anyone interested in electronics.  Need a panel of buttons to control your custom digital piano?  Hook up a button board, plug the Chomp into your computer, and you’re done!  But it’s much more powerful than that… if you’re on the more advanced side of things, the Chomp is 100% arduino compatible, meaning you can load your custom code to do anything!

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So, what is this mystery device?  I’m calling it the CHOMP, or Configurable Hardware Open-source MIDI Platform.  It’s my first major circuit-design project, and it’s going to be awesome.  The Chomp uses an ATMega328 running the Arduino bootloader to read up to 48 analog and digital signals and output a MIDI signal to do, well, anything!  This device will aid tremendously in the construction of custom music projects.

Seriously, though, this thing is pretty sick.  You program it just like an Arduino, plug buttons, knobs, and switches into any of the 48 inputs, and plug it into your computer, all with no extra drivers!  There’s even support for new-fangled USB midi with the included adapter.

Best of all?  The entire project is open source.  Don’t believe me?  Download the latest circuit files (in EAGLE) here.  The design is free for you to modify, build, and share.

“How might I procure one of these fantastic boards,” you might ask?  Unfortunately it’s going to take a little while for the first prototype boards to get here. Then I have to assemble them.  And then test. And then test some more.  You should be able to buy your very own Chomp sometime this May!

Note: MIDI-in doesn’t really do anything at this point.  I didn’t connect it because I couldn’t really figure out what to do with it!  I went ahead and optoisolated the signal, but right now it’s just floating around.  When boards are here I’ll start messing around with it in the proto area of the board in the lower right.  Suggestions are welcome!  MIDI-in is now working perfectly!

UPDATE 1/11/12

BLAST!

I just discovered a minor bug with power management, but just sorted it out in the EAGLE document.  Of course, I have already ordered the prototype boards so I’ll have to do a little hacking once they get here, but the problem is fixed.  The issue was that I was treating the LM1117-5.0V regulator like an LM317, so I had too many resistors and capacitors (one at the wrong capacitance).  Thus, things got quite a bit overcomplicated.  Sure, it’s a little frustrating to have found a bug before the boards even get here, but consider the lesson learned!  I’ve also added pull-down resistors to the master 4051.

UPDATE 1/16/12

Okay, so say you want to build your awesome new MIDI controller but you absolutely suck at soldering.  Or, say you are  making a button panel and don’t feel like soldering each and every pull down resistor.

What a coincidence!  Here are two boards I designed to solve those two problems.

First up, the Chomp Button Board, for all of your button-connecting needs.  There’s even a handy guide silkscreened right on the board for how to connect switches and pushbuttons!

There’s even pull-down resistors soldered right on for you so you don’t have to worry about floating pins.  These pull-downs are actually a little bit optional… it appears the master pull-down resistors on the main multiplexer act on the whole system.  I added them just to be safe.

Next up, the Chomp Potentiometer Board!  Never struggle with connecting a potentiometer again!  Once again, handy guide printed right on the board.

Digital images are misleading – these two boards than 2 inches across.

I’m currently deciding how many of each to include with each Chomp.  Perhaps I’ll sell a couple of different bundles for each option, and then sell each daughter-board individually as well.  They’re really completely optional if you know how to solder buttons and pots well.

So, those are the advancements!  Stay tuned, folks.

UPDATE 1/18/12

Guess what?  BOARDS CAME!!!  It’s hard to describe what it’s like to actually hold one of these boards in your hand.  It’s absolutely TINY!

(This is an old version of the board.  The latest version is in the prototype below!)

I’ve decided it’s a better use of my time to not bother hacking the power issue (along with a few other minor bugs I’ve discovered along the way), and simply order new boards.  Notice that I haven’t actually soldered anything down yet (that’s why there aren’t any SMDs on the board).  This way I don’t have to worry about my little hacks and jury-rigged fixes getting in the way of actual improvement.  Once the new boards come, code writing will be the next major step.  So, the really good boards will be coming next week.  But this was a major, major advancement!

UPDATE 1/23/12

I just finished the first prototype – it lives!  Download the code here.  I should be submitting a kickstarter relatively soon to see if I can get funding to build a few hundred of these.

The board is even faster than I expected.  There’s almost no delay (and definitely no perceivable delay) between changing the state of a pin and seeing the value change on the screen.  I’m so excited to get more working boards made!