This is a recent project I have been working on for the Alliance Theatre's production of Eurydice.

I made it with a simple wireless circuit. With this tool, the actor will be able to control the sound

cues from stage with his movement. As you can see in the last picture, it is an instrument that

resembles a lyre, but is more industrial modern looking to match the design of the show.

 

Mechanics:

The digital encoder in the transmitter takes basic contact closure information

using a 5VDC supply to make an 8bit information packet, which is then sent to

the transmitter. The encoder, as seen has 4 voltage pin sets. After the

information is converted into a single packet stream, it is sent to the

transmitter circuit. The transmitter is transmitting at around 433MHz, which is

the VHF spectrum.

Because this is a simple and inexpensive wireless circuit, encoder and decoder, the frequency is not adjustable.

The receiver receives the packet information and sends it to the decoder, which then

recreates the corresponding voltage on the appropriate pin. I then have the 5VDC

information going to a relay circuit including a protection circuit to reduce misfiring, or

damaging of the decoder. The 5VDC relay is then wired to 1/4" TRS connectors, so

that it can be connected directly to a Midi Solutions box, which converts contact

closure information into controllable Midi strings. That is then connected to

our Q-lab system.

The above diagram shows four relay circuits, which I did use in the receiver, however the

transmitter only ended up needing three, as shown in the pictures below.

Here you can see how small the transmitter circuit is. It fits easily within a 1.5" PVC pipe,

but could easily be placed in just about anything.

As seen the transmitter runs off of only three AA batteries, which last a very long time.

The receiver also runs off of 5VDC. I used a simple AC/DC power converter since this

unit is not mobile. I also added an on off switch and an indicator light.

In this image you can see I cut a hole out for the Antenna which helps its range a bit, but

it was not necessary. The range in a free field is around 90'-100' and since this is operating

within the VHF spectrum, the signal will go through most walls.

This video was taken after the initial build of just the circuitry so it is a bit messy, it does however

show the overall idea for how it will be used. I will post a working video as it becomes available.

 

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