I am totally new to this world, but am a software programmer with a strong analog electronics background.
I am attempting to build a control surface for controlling audio recording software.
Here's a nice illustration the motorized fader concept:http://www.youtube.com/watch?v=toj8JRJ-4rI&feature=youtu.be
Each fader requires 5 pins:
1 analog pin to sense the wiper
2 I/O pins for touch sense
2 PWM pins to drive the motor via an H bridge.
There would also be 2 dual concentric ELMA E37 rotary encoders with push top switches:http://www.leobodnar.com/shop/index.php?main_page=product_info&products_id=196
That's 10 more pins:
2 per encoder x 4 = 8
1 per switch x 2 = 2
As well I'm thinking of using 2 x 4D uOLED-128-G2 displays (one for channel status and one for metering)http://www.4dsystems.com.au/prod.php?id=84
As far as driving the metering display, I'm thinking of loading background images from the 2Gb SD card included on the display board and just doing "delta" meter drawing to save bandwidth.
I believe these guys need 3 pins each - so total 6 pins.
We also need 2 more switches -- 2 more pins
So 23 pins per channel.
I was hoping to drive 4 of these "channels" with 1 Arduino Due but that would require 92 pins.
I also would like to use Ethernet for communication.
With the Due running at 84 MHz is it feasible to multiplex the simple on/off switches and still have a very responsive system, thereby getting within the avaiable pin count?