Waterside shoot
I've been meaning to make a video here for a while (see 09 Sep 2020), though my original idea was to have units floating in the river and rotated by the current. I am still a little way off making a good floating unit, but at least these ones rotate.
Walthamstow Marshians
Despite the witty title implying sources of weird noises, the music from these is tame compared to some earlier versions (eg this).
One day I will get a good audio recording of the space, but this was another poor effort, as my microphones were too close to the units and picked up the motor noise more than the music. I knew this was a risk, and spent some time tuning the motors so that each of the discrete speeds the motors ran was in tune and in key with the notes from the Randomatones. The motors are driven from a pulse width modulation (PWM) output from the Raspberry Pi (via a couple of power transistors), and I achieved the tuning by selecting the appropriate width and pulse of the PWM. This sounded convincing indoors. Outside, all you can hear is a tuneless whining buzz like an electric shaver.
One of the things that attracted me to this location was the ledge on either side of the thoroughfare on which I could set up the units without being in the way of passers-by. Having only ever biked along it, I did not realise until I got there for the video that the ledge was above my head height. I insist on showing you how bad I was at climbing up onto it. I must have done so at least 12 times during the shoot. Sadly practice made no perfection, instead I got worse and worse at it.
One day I will get a good audio recording of the space, but this was another poor effort, as my microphones were too close to the units and picked up the motor noise more than the music. I knew this was a risk, and spent some time tuning the motors so that each of the discrete speeds the motors ran was in tune and in key with the notes from the Randomatones. The motors are driven from a pulse width modulation (PWM) output from the Raspberry Pi (via a couple of power transistors), and I achieved the tuning by selecting the appropriate width and pulse of the PWM. This sounded convincing indoors. Outside, all you can hear is a tuneless whining buzz like an electric shaver.
One of the things that attracted me to this location was the ledge on either side of the thoroughfare on which I could set up the units without being in the way of passers-by. Having only ever biked along it, I did not realise until I got there for the video that the ledge was above my head height. I insist on showing you how bad I was at climbing up onto it. I must have done so at least 12 times during the shoot. Sadly practice made no perfection, instead I got worse and worse at it.
First video shoot for rotating units
I took the red prototype and a second blue unit to a railway bridge in the Walthamstow Marshes earlier today to make the next Randomatones video. The acoustic was reasonable, though I was mainly drawn to this location because it is a quiet railway underpass rather than a noisy road bridge. Also it had a handy ledge for me to climb up on and attach the units without a step ladder. Though I was there early in the morning, this passage was a surprisingly busy thoroughfare for dogwalkers, joggers and cyclists. Not one seemed remotely bothered that I was attaching mysterious devices to the underside of their bridge.
Stairwell test
Testing the rotation of both units on the stairs before going out to make a video of them somewhere out in the wild. The test was worth it, as I had set the voltages on the blue motor too low, and it didn't turn.
Frame for another rotating unit
Before assembly, sometimes the empty frames look appealing just by themselves. I love these acrylic fluorescent paints, glowing even in the cloudy daylight. This one has been carefully measured and constructed around the battery, with an arm each side to support a speaker. Then I take it apart again for painting inside and out, somewhat unnecessarily, as the battery will cover up some of the painted surface.
Sirenatone prototype
Back after several months away with a prototype hanging spinning Randomatone. This one has a 40 RPM geared motor whose speed is varied using one of the PWM ports on the Rasperry Pi. The motor mechanism issues its own clearly audible whine, but by using some combination of PWM voltage and frequency, I am wondering if I could tune the motor to the Randomatone notes. I want variable speed, so that several together will all rotate differently and chaotically, but I would be happy with them shifting between discrete speeds rather than varying continuously as now.
Also note the introduction of a cheap plastic horn speaker. Compared to the other more hi-fi cardboard cone speaker, its sound quality is poor, but the squawky mid-range of the horn does suit some of the rougher waveforms the unit generates. It's also lighter and more weatherproof than the card-cone speaker. Not that I plan to hang these from trees or lamp posts just yet.
I will probably rethink the decorative red and blue LEDs. It looks like a kind of weird megaphone, but when I watch the thing spinning I think of a siren on a police car or fire engine. A Sirenatone. (I doubt I will call it that for long.)
Also note the introduction of a cheap plastic horn speaker. Compared to the other more hi-fi cardboard cone speaker, its sound quality is poor, but the squawky mid-range of the horn does suit some of the rougher waveforms the unit generates. It's also lighter and more weatherproof than the card-cone speaker. Not that I plan to hang these from trees or lamp posts just yet.
I will probably rethink the decorative red and blue LEDs. It looks like a kind of weird megaphone, but when I watch the thing spinning I think of a siren on a police car or fire engine. A Sirenatone. (I doubt I will call it that for long.)
