Copyright (c) 2018 Matthieu Metzger

  "Systole's Gnu Ideas" is free software.
  You can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2.1 of the License, or (at
  your option) any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  Lesser General Public License for more details.

  A copy of the GNU Lesser General Public License can be found there.
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  copy, write to the Free Software Foundation, Inc., 59 Temple Place,
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Midi Harp

 - metallic strings as touch sensors
 - midi note sent when the string is released
 - release time -> note velocity
 - auto-mute when a lot of strings are touched
 - metallic table for percussive sounds or mute
 - optional control change or note on touch
 - multiplexer for more strings
 - simple pedalboard to simulate the chromatic harp


 same behaviour as the midi harp

 - long switches send notes when they are released

Hurdy Gurdy

 - drawing pins or metal rectangles as keys
 - motor / dynamo as a wheel -> analog input
 - the keys could be glued to some rubber band to better the feeling

 - polyphonic capabilities as an option
 - different midi channels for each string

Midi Surface

 - each touch key and led on the same pin
 - piano keys mapping
 - slider mode :
		- beginning on first or last key gives a full range CC
		- touching a single key gives the absolute value
		- sliding it in the middle, "smartphone like", makes a relative change to value
 - menu key which gives access to the midi settings, channels, controllers, notes etc. for each key
 - each key is a sub-menu, whose name is written on top of it
 - the leds show the current preset, blink / move on edit
 - keys pressure to some cc ? aftetouch for piano
 - experimental velocity detection from touch speed

Midified piano

  - very small magnets put vertically on each key front
  - magnetic switches or hall sensors for each
  - all the sensors can be put together on a thin bar, easy to carry and install

  - the hall sensors should give enough data to detect velocity ( keypress time )
  - multiplexer for more keys

Optical Passive Mixer 

 * mono channel

   - one photoresistor
   - second photoresistor on the same light source for balanced operation
 * for stereo mixing, use two mono channels from the same mono input

 `Arduino controlled`

   - with software slow pwm to control 6v bulbs ( one for each mono channel )
   - midi implementation


 `Screen controlled`

   - simple Processing app for computers and android, that transforms cc values in squares of light
   - values from touch GUI, keys, midi input or file


        audio in ------ :::: ------ audio out                        

                    light square
                     on a screen



       -----------------[:::]------- left +  ----->
       |             (left bulb)
       |       ---------[:::]------- left -  ----->
       |       |

      in +    in -                                    to passive summing

       |       |
       |       ---------[:::]------- right -  ---->
       |             (right bulb)
       -----------------[:::]------- right +  ---->

The simpliest version could be : Volumizer
                                 Add Volume and Pan to any signal, thanks to 3 tactile switches and leds, memory preset and midi input

Shiny Click Box

 Add metronome and midi outputs to everything with has screen :

  - photoresistor putted on the screen as a detector ( with a black small enclosure to avoid light from behind )

  - Trig by a simple video file with quality audio and metronome flashes encoded on the video stream,
    or an application to play audio on headphones and a synchronized midifile on screen

  - multiple resistors can be routed to multiple click tracks, or send midi events
  - variable luminosity can be used to send control changes

  With Arduino and photoresistors, or maybe just with a simple transistor oscillator powewered by the photoresistor, and some control (volume, pitch, audio in jack to mix with the click sound)

Gnu Ideas

open source& custom devices
by matthieu metzger