The aim of this thesis is to present the development and making of a musical interface for stage lightning control. The choice of this field is related to my personal requirements as a member of a music group, which needed a way of changing stage lighting during live performances according to the beat. After unsuccessfully trying to find something suitable on the market, I compiled a list of desired functionalities based on what commercially available devices could offer as well as a few of my own ideas, one of which is computer connectivity which enables future software upgrades.
The core of the system are piezoelectric sensors, connected to analog inputs of a processor. We attach them directly to the drum heads, but any other instrument would also work. When hitting the drum, piezoelectric sensor generates voltage, which is processed by the microprocessor. With every detected hit, the device can send out MIDI notes, which can be changed by the user. The system has 5 input channels, meaning it can detect 5 drums at the same time. With every input channel, we can control one or more lights in the connected DMX universe. By adjusting ADSR envelope (Attack, Decay, Sustain, Release ) parameters, we can set a lightning profile for every channel. Adjusting is done on the device, using rotary encoder with a switch and the data is displayed on the LCD.
The device was tested during a rehearsal of a music group. I was mostly focused on the response of the device and its immunity to incorrectly determined drum hits. Measurements have shown, that the device’s response is negligible compared to the DMX universe refresh rate. Most of the incorrectly detected hits can be easily eliminated by raising the threshold of detection. We can hit the next drum, and raise the threshold until we can no longer see any incorrect detection.
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