Hi friends! How are your projects going?


I'm attending a BeagleBone-based musical accessibility hackathon this weekend, and will be shooting some footage of the hacks & projects people build for my next update video- should be a good one!


In the meantime I wanted to post a little update about LaserScope Music. I've been spending a lot of time sat watching the output of my Puredata patches on an oscilloscope to make sure I'm getting the desired effect within the sound waves themselves, however as some people (most notably rsc) expected, the tiny HDD arms were struggling due to inertia once I had managed to attach the pieces of mirror I had cut. So that I could begin experimenting with other ways of constructing my laser galvo, I built a new cardboard prototype that would allow me to measure how much movement output I will get from the laser at varying distances, whilst manually adjusting the angle. This way I can measure how much angular motion I get from different motors & HDD parts, and calculate what will be suitable without having to construct lots of experimental-stage prototypes.

Cardboard galvo prototype

As you can see, the prototype is pretty basic and extremely hacky - being constructed from cardboard, rivets, expanding polyurethane glue, wooden skewers and some little pieces of mirror that I cut up. So far it's led me to believe that if I use larger HDDs I should still be okay to continue with this approach - they should have enough of a range that I can still draw a large area with the laser even at a short distance, but should also be powerful enough to overcome the inertia caused by the weight of the mirrors whilst still moving at a high enough speed to draw the sound waves created by my BeagleBone Black. As you can see, compared with how small the assembly would have been if I'd gone ahead with the 1.8" HDDs, the prototype is pretty large, but once I have worked out the details I should still be able to get the final object to be pretty small. My current plan for the final form-factor is to have the BBB and control panel mounted in one small desktop case, and then the amplification circuitry, laser diode and galvo assembly in another box, with cables for line-level audio and power connecting the two boxes. This is so that I'll be able to perform with the device without having to worry that my interaction with the control surface will cause any unwanted movement or shaking of the output projection.


That's all for now, folks. I'll go over some of the functions of my oscilloscope music pd~ patch in my video this weekend. I'll be surrounded by BeagleBone Black audio/music experts at the hackathon, so if anyone has any questions for any of the team at QMUL please send them my way and I'll do my best to get you some answers.


Party on!