The Theramidi

 

The Theramidi is a new musical device, based on the Theremin. The TheraMidi produces a MIDI signal relative to the movement of objects to or away from it. The MIDI output is controlled by the intensity of Infra-red light reflected from objects ( e.g. hand movements) using two Infra-red transmitter/receivers. 

 

One Infra-red device determines the note pitch/frequency and the other can be pre-programmed to control a variety of MIDI effects e.g. Volume, Modulation etc. However the default control is Volume. The MIDI Channel can be selected with a 4-way DIP switch

 

 

 

	The TheraMidi  ITEM#: THERAMIDI PRICE:  €35.00

 

 

 

The TheraMidi utilizes:

• A Miduino kit including a suitable pre-programmed Atmega168,
• A 2.1mm power socket, and associated LED, 
• A 4-way DIP switch, which selects the MIDI channel, shown in table 1
• A MIDI 5-pin DIN input socket,
• A MIDI 5-pin DIN output socket,
• A MIDI activity associated LED,
• The circuit schematic is available,

 

 

 

The TheraMidi requires:

• A 9 Volt battery or equivalent 9 Volt DC power source
• 2 Infra-red distance sensors 

 

Circuit Schematic:

A circuit schematic for the TheraMidi shows the Infrared connections. The design uses two Infrared Proximity Sensors from Sharp GP2Y0A21YK which has an analog output that varies from 3.1V at 10cm to 0.4V at 80cm. Other  Infrared Proximity Distance Sensors with analog outputs can be used but the software may need to be adjusted to get the correct ranges.

 

Assembly:

The kit includes all parts necessary, the assembly is straightforward and well documented. This design does not include a USB chip, it is designed to use a FTDI USB 232-TTL cable to program the microcontroller.  However since the cable plugs directly into the Miduino, you can use one cable for multiple Miduinos.

   

MIDI Wiring:

The MIDI IN and OUT connections use 5-Pin 180 degree DIN sockets. Note that the MIDI IN/OUT wiring is polarised and the correct pins should be used.

  

Programming:

Note, because the MIDI IN Opto-coupler shares the same serial input as the USB interface, when programming the Miduino the MIDI IN connection has to be disconnected.

 

Expansion:

The 16-Way drum inputs to MIDI Output units can be combined/expanded by connecting the MIDI OUT of one unit to the MIDI IN of the following unit.

 

Download:

Open the  source code file and copy and paste it into the Arduino programme and save it as a .PDE file.

 

 

 

 

Details on Pitch Bend and Pitch Bend Range Sensitivity adjustment.