Sistem za instrumentalno upravljanje z MIDI napravami in DMX vesoljem

ŽIVIC, TADEJ (avtor), Pirc, Matija (mentor)

V okviru diplomske naloge sem razvil in izdelal instrumentalni vmesnika za kontrolo odrskih luči. To področje sem izbral zaradi lastnih potreb, saj sem član glasbene skupine, ki je pri izvedbi skladb potrebovala spreminjanje svetlobe po ritmu. Na trgu nisem našel komercialno dosegljive naprave, ki bi ustrezala vsem mojim potrebam. Iz vseh podobnih najdenih naprav sem določil vse dobre lastnosti, ki bi jih lahko vključil v svojo napravo in jih skupaj z nekaj mojimi idejami tudi implementiral. Med njimi se nahaja tudi povezljivost z računalnikom, ki napravi omogoči nadaljnje programske nadgradnje. Jedro sistema so piezoelektrični senzorji, priključeni na analogne vhode mikroprocesorja. Piezoelektrični senzor pritrdimo na opno bobna ali na kakšen drug inštrument. Pri udarcu na boben piezoelektrični senzor generira napetost, ki jo mikroprocesor zazna. Ob vsakem zaznanem udarcu mikroprocesor pošlje sporočilo na MIDI izhod in glede na nastavitve začne spreminjati svetlost odrskih luči. Sistem ima pet kanalov, kar pomeni, da lahko zaznava udarce po petih bobnih hkrati. Vsak boben lahko vpliva na eno ali več odrskih luči. Za vsako luč lahko nastavimo profil prižiganja in ugašanja s parametri ADSR ovojnice (Attack, Decay, Sustain, Release). Nastavljanje poteka na napravi, z uporabo rotacijskega enkoderja s stikalom, podatki pa so prikazani na LCD zaslonu. Napravo sem preizkusil med vajami glasbene skupine. Zanimala me je odzivnost naprave in njena imunost na napačno zaznavo udarcev. Meritve so pokazale, da je odziv naprave na udarec zanemarljivo majhen glede na periodo osveževanja DMX vesolja. Večino napačno zaznanih udarcev se enostavno znebimo z dvigovanjem praga zaznave napetosti na signalu iz senzorja do take meje, da presluhov med bobni ne zaznavamo več.

• Jezik: Slovenski jezik
• Ključne besede: DMX, bobni, MIDI, odrska osvetlitev, mikrokrmilnik, svetloba, luč
• Vrsta gradiva: Diplomsko delo/naloga
• Organizacija: FE - Fakulteta za elektrotehniko
• Leto izida: 2020
• PID: 20.500.12556/RUL-119676
• Datum objave v RUL: 10.09.2020

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Instrumental Control System for MIDI Devices and DMX Universe

Izvleček

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.

• Ključne besede: DMX, drums, MIDI, stage lighting, microcontroller, light