Final Mechanism Thoughts

Posted on Nov 4, 2013 in Physical Computing
Final Mechanism Thoughts

Final project- doubling down to resolve audio-player issues.

I, like so many on the floor today, seemed to be trouble shooting things we thought we’d solved.

  • My H-bridge, motor, & 9V w/ resistance side of things isn’t quite up to snuff, mostly because I think I need to add 10 ohms instead of 20 ohms to the main circuit (for the bridge and motor) and then add supplemental resistance to the parallel potentiometer and ground. Dropping the voltage to 5V is just radically underpowering that toy-motor. Clearly time to re-run all the math and double check all the recommended amp values. Either way, I soldered everything to a pcb board for practice (knowing I wasn’t quite going to be getting enough power w/ my toy motor to do anything fancy).

But none the less, I think my final project, should I decided to build on my experience, would be to continue with the audio-film player.
This is hard to say after a week of reduced expectations, but there are several paths to follow. I do wish there was more of a serial/processing interaction to be had, but perhaps some sort of re-coded, generative vj imagery could be tied in to the system. Before I wrap my head around that,

things to resolve:

  • the wiring issues- the pcb connections seem flimsy (pins and shields instead of wires off the board?) and I’ve still got too many cluttered areas (if the internal film reel were to actually work). Purely mechanical and spatial consolidation and access needs to be revised.
  • the electronic issues- see above- Not only does the voltage (up) and resistance (more discrete) need to be rethought/recalculated, I think I’m going to have to redesign, simplify and/or expand the space of the reel reader. There wouldn’t be anything wrong with  examining traditional reel-to-reel set-ups (instead of a belt loop) or working more with gearing and reducing edge friction on the belt system. It needs to be tested fairly quickly to determine power needs and negotiated with the above issues. Ironically the light, photocell, and general sensor side of things seems to be going smoothly in comparison with the feeder system.
  • the induction problems- as I attempt to connect the screw connections, my miniature screw driver keeps falling into the box or being picked up by my speaker system. I can’t help but wonder how that much of a magnetic field, directly over the arduino, is affecting all of my analog input readings. Space as insulation or ????
  • Code conflicts- right now, the sound is tolerable when abstracted into tones, but that means putting a musical delay in the main loop with the dc motor, which produces an inconsistent read/power situation. I know I need to rebundle functions in order to nest the delay.  I also need  to brainstorm what I want to get from the original analog read (since the photocell film reader isn’t as tight as desired/in the patents). Perhaps I have to re-conceptualize it as a trigger- if I tie speeds to delays, it might be useful to set up alternate, coded tonal sequences ( a little too discrete?) or maybe the magic really lies in getting the motor-speed adjustments to work and having a couple dueling strips adjacent to one another.
  • Interface issues- I actually think the turntable is decent at what it does as a knob (although 5″  diameter is too large for petite hands) and the placement of the power switch and momentary motor-reverse button makes sense. Volume next to the speakers is useful and intuitive, but that system likely needs to be displaced. The incidental power light is kinda cute, but perhaps I’ll utilize a second LED if the reader housing gets moved to accommodate reel turning mechanisms.


(It looks so peaceful and harmonious, just sitting there turned off… but there is some serious amour fou with this obsolete audio player system. 😉

I’m not going to be able to sketch some alternate spatial arrangements in the next hour (before 8pm) or add the wiring diagram that needs to desperately to be documented… but I’m aiming to get those up onto the site by class tomorrow.