This is quite handy:
http://arduinodrums.blogspot.com/2010/05/more-notes-on-cd74hc4067.html
Basically you buy an Arduino and one of these: SparkFun Analog/Digital MUX Breakout - CD74HC4067 - SparkFun Electronics ($4.95) and you instantly get 16 analogue pots. The good thing about this mux pcb is that its really cheap and you can use multiple mux’s… 64 pots should be feasible, if you’re using an Arduino Mega, for less than £50 in total (if you buy an Arduino Mega clone for £20 like I did!)
I am using a arduino mega and making a custom MIDI fighter as a prototype for my own all in one controller 
Just doing it as an exercise to see whether I can do it.
I am making a controller featuring full LED feedback on 16 fully lit arcade buttons, 4 LED encoder and 2 super FX faders.
Should have it finished in time for late April 
Hey Guys,
i´ve just orderd my arduino mega clone… I would like to connect it to my DIY 4 Deck Transport/Loop Controller for Traktor i´ve build with the pcb of an gamepad and an usb Keyboard. It Contains 4 Pots and 41 switches (16 Arcade Buttons and 25 smaller Buttons). That dosen´t worked that well (response, seamless pressed buttons, “jumping” values of the pots, no LED feedback..) and now i would like to try it in a better way
because of the fact, that i am absolutly not into programming im a bit scared about my “new” Idea.
Is it posible to connect the pots, buttons and as mutch leds as posible directly to the arduiono without multiplexers? And my other question: Do you think i could write the Code myself or is it too hard for a total noob?
Thanks for some replys!
45 pins would be required for your setup, so the mega should work okay without using multiplexers.
As for coding it yourself… Do you know C++? Have you programmed before?
no… absolutely not Maybe a friend of mine could help me… I think i´m going to try it with this Tutorial
If i am using 45 Pins for my Controller, could i use the other 9 Pins for LED´s? or is there an easy way to connect more LED´s?
That tutorial is for creating libraries for use in the arduino environment.. NOT how to create a program for the arduino… A better tutorial would be: Arduino Tutorial - Learn electronics and microcontrollers using Arduino!
As for leds, yep, you can use the remaining pins for leds… In order to get more you would use shift registers (such as a 74hc595).
Im gonna use an arduino for my project…i hope i can understand the code tho! what is the coding actually used to tell the arduino?
You program the arduino in C/C++
Yeah but why do u need to program it
How else is it going to do what you want it to do?
I thought it just sent midi notes…sorry i am a noob and their site is pretty vague
The arduino? Not at all… You can program it to send midi notes though.. The arduino is a development board that allows you to easily program the Atmega328 microcontroller that it contains (or whatever chip the board uses [ATmega1280 or ATmega2560 in the mega’s]).
The microcontroller is a general purpose cpu that can do just about anything you want to it to do…
Examples would include:
Self Balancing arduino robot directly controlled with a Wiimote
Arduino Dice Game
Arduino TVout Light Pen Demo
My Arduino Web Server v2.0
Ohh wow lol didnt know that at all. So how hard is it to program it to send midi notes?
Well see… You will also have to program it to read all the buttons, decide if they have been pushed (including debouncing to remove button jitter).. You also have to read the analog values of the faders or pots..
To be honest, based on your questions and responses.. You would be much better off using something like this: Livid DIY MIDI Products instead of an arduino.
Meh ive looked up that but it cost like 4 times as much as an arduino. im willing to learn.
Okie dokie
In that case, I’d suggest that you start here: Arduino Tutorial - Learn electronics and microcontrollers using Arduino!
The arduino forums are a wealth of information: Arduino Forum
You will have a bunch to learn before you should try your hand at a midi controller.
If you can learn the programming and the electronics, a midi controller isn’t all that difficult.
Thanks buddy
depending on your I/O needs, I’d recommmend a Highly Liquid Midi CPU instead… not much more expensive than an Arduino Mega but MUCH easier to get up and running. Also, the owner of the forum will program it for you if you tell him exactly what you need.
Oo thanks for the info! looks great and is affordable. Looks like 128 digital inputs and up to 14 analog right? That sounds great
You realize that that is the same product that I linked you to originally…