EWI-USB Plus project (updated in 02/2022)

Updated: Feb 21

I modified my EWI-USB recently. The number one goal is to make an EWI-USB more portable - shorter/smaller enough to put into a carry-on suitcase. I aslo added two way midi controller - pitchbend - in order to add more expression controls. I used Tom Scarff's midi to ribbon controller (Arduino USB) - which sends pitchbend data from the ribbon sensor. My music performance platform, Cantabile Performer, has excellent midi filters mapping the pitchbend to various MIDI CCs. Now I can do extra-smooth pitch bending via ribbon controller and can also setup the ribbon controller to control portamento, growl, program change, etc. So I decided to call my EWI-USB as "EWI-USB plus".

1) Preparation

1. dissemble the EWI-USB. remove 3 parts of weights

2. cut the end part - about 2 inches

2) Add a Ribbon to midi controller

- Unfutunately this kit is no longer available. But you can get a similar kit from MIDI MUSIC KITS website and I believe you can program it. (I purchased a new kit from Tom Scarff again. This is still available for purchase as special order. You need to contact him by email .)


Ribbon controller programming post from Arduino forum


MIDI Ribbon Controller : by Tom Scarff

This is a simple MIDI project, utilizing the Arduino design, to output MIDI Note ON/OFF and Pitch Bend control signals when a ribbon/softpot variable potentiometer is adjusted. When the ribbon/softpot is pressed a MIDI Note On message is transmitted. While it is still pressed a MIDI Pitch Bend message is sent if the finger is moved. When the finger is removed the MIDI Note Off message is transmitted.

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The MIDI Ribbon Controller unit utilizes:

  • An assembled, built and tested Arduino board including a suitable pre-programmed microcontroller,

  • A 2.1mm power socket, and associated LED,

  • A MIDI detection LED,

  • A 4-way DIP switch, which selects the MIDI channel at power-on, shown in table 1

  • A 150mm wired MIDI 5-pin DIN input socket,

  • A 150mm wired MIDI 5-pin DIN output socket,

  • 0.1" pin-terminal inputs/outputs,

  • The circuit schematic is available,

  • MIDI available/transmit LED

The MIDI Ribbon Controller also requires:

  • A 9v battery or equivalent DC power source

  • A 100k ohm 0.25W resistor

  • A ribbon/softpot linear potentiometer (Sparkfun Electronics)


A MIDI Ribbon control signal is transmitted when a softpot variable potentiometer is adjusted. The ribbon/softpot controller is available from Sparkfun Electronics in different sizes.

Note: The ribbon/softpot potentiometer is not included in the price.

The MIDI command is channel (1-16) dependent. The MIDI channel, that the volume controller affects, is set by the 4-way DIP switch selection, shown in Table 1 below.

Design Requirements:

The design is a compromise of the number of individual notes that a finger can play separately on any given ribbon controller length. It is similar to a violin. Except a violin has continuous pitch changes along its length. Whereas the ribbon has specific MIDI Note On positions and THEN variable Pitch Bend. If you consider the width of a finger is 1/2" to 3/4" then the controller length can be divided by these values to determine the maximum range of notes. The ribbon/softpot controller is available in different lengths. For a 18 inch (500 mm) long ribbon controller with 3/4" finger, number of notes would be 24 For a 300mm -11.81 " long ribbon controller with 3/4" finger, number of notes would be approx. 16 For a 200mm -7.84 " long ribbon controller with 3/4" finger, number of notes would be approx. 10 For a 18 inch (500 mm) long ribbon controller with 1/2" finger, number of notes would be 36 For a 300mm -11.81 " long ribbon controller with 1/2" finger, number of notes would be approx. 24 For a 200mm -7.84 " long ribbon controller with 1/2"finger, number of notes would be approx. 16 So there is some compromise in choosing the design parameters. Perhaps if used by adults or children. However if you choose one of the above, number of notes choices, it can be pre-programmed into the design.

Update August 2021

I was able to make the pitchbend kit much smaller and to hide its cables inside EWI-USB body.

Update February 2022

I added 2 MIDI Expression controllers (Audiofront) and a Hot hand USB wireless midi controller on my EWI-USB. now more powerful than EWI 5000.

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