Arduino music controller with motorized faders

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi, I'm just thinking about my project of music controller.

Some parts will be handled by Arduino.

  • Motorized faders
  • Rotary encoders
  • Hundreds of leds using max7221

And i want to ask some questions.

  1. Is Arduino enough powerfull to handle it? (8 faders [8potenciometers and 8 h-bridges], 24 rotary encoders, 8 max7221 led drivers) :-?

  2. Can I use rotary encoders with multiplexers like 4051?

  3. Can I use H-bridge like L293NE with multiplexers?

I've done example with motorized fader and one Max7221

Creator of iPhone controlled RC car using Arduino -> http://josef-prusa.eu/obsah/blog/iphone-controlled-rc-car-eng.html

2

I think that trying to keep track of 24 rotary encoders at the same time will be VERY difficult. Especially if you have to keep track of "hundred's" of LED's and 8 motorized faders at the same time.

Arduino only has 1KB RAM to store all the information for the "states" of all these devices.

And (i think) the rotary encoders are difficult to monitor without interrupts, which Arduino has 2 of.

3

Monitoring so many rotary encoders is difficult in software alone. However, you can use two chips (latch and gates) to convert the signals from the encoder into a pair of "step" and "direction" signals that are much easer to monitor as they don't bounce and only change in real time.

4

Who says that you have to limit yourself to one Arduino Board.

Try to modularise your design, Since everything is a multiple of eight, you can start by building a prototype controlling 1/8 of your system, and then scaling up.

It is always much easier to debug a smaller system.

Magnus

5

Thanks for replies.

I've just ordered Atmega128 to build own Wiring board (compatible with Arduino), which probably will be more powerfull and I hope it can handle it all alone :slight_smile:

Another silly question, if I use multiplexer for multiplexing outs for controlling motors thru h-bridges, will it work? I'm not sure, because i will not get continuous power but pulses (am i right?)? Should I put a capacitator for stabilizing?

Grumpy_Mike >> I'll look at it, it sounds good!!

6

You are correct, if you use multiplexing, there is a good chance of the motor controller receiving pulses instead of a continuous signal. It rather depends on the design of the multiplexer, in fact.

7

if I use multiplexer for multiplexing

Yes but don't. Use a multiplexer for increasing the number of outputs. That means using one with a latch in it like 74LS259.
I use one in my latest project:-
http://www.thebox.myzen.co.uk/Hardware/Transistor_Tester.html

It gives 8 latched outputs. Alternately use a latched shift register, that uses even fewer pins.

8

Grumpy_Mike > I hope it will work with my 4051 :smiley: because I've ordered few :smiley:

Btw: are you monome fan? http://translate.google.com/translate?hl=cs&u=http://josef-prusa.eu/obsah/blog/zkousime-monome-vlastni-tvorba.html&sl=cs&tl=en&swap=1

9

BTW, maybe its crazy idea, but can I use led driver for managing this motors? I thinks there is not so big pulses and if I add transistor to get higher woltage?

What do you think?

10

If anyone intersted, I did little update with my controller, Asus EEE based. Arduino will come with hardware parts like faders and knobs :slight_smile:

11

in my books that qualifies as uber cool :slight_smile: , i would have gone for an acer aspire one , great net book , smaller , cheaper , bigger screen.

P.S Ive got one ::).

12

hi prusajr : )

i just saw your video on vimeo with the motorised fader ,totally cool!

i know max msp pretty well and would love to make a flying fader system, is there a tutorial online or a list of components needed?
or did you just work it all out yourself? thanks for any advice!

: )