» MAKE: NOISE — Discuss this article

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• Arduino?
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  A large portion of this magazine edition is centered on Arduino. I'm curious as to whether the lamp could be modded to use an Arduino controller for the LED's. Would each LED need its own board, or can an Arduino board control three LEDs? If one board will do the job, can a program be written so that the lamp changes colors gradually; creating infinitely possibilities?
  
  Did you research whether a large salt crystal is commercially available? If so, any leads?
  
  I'm also curious as to what the bottom of the crystal looks like. Did you hollow out a small area in the bottom, drill three holes or just have the LEDs contact the bottom?

  Posted by jyossarian on January 24, 2011 at 12:37:42 Pacific Time

• Picaxe current per pin overload?
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  1) For the Picaxe circuit shown on pg 151, I get for blue and green LEDs (Vf=3.5) per pin current of 75 mA, and 33 mA for red LED (Vf=1.7).
  
  Based on the Picaxe manual " each output can sink or source 20mA" ... this seems high.
  
  Is there something I'm missing here?
  
  2) Also, any thoughts if all three LEDS could be driven with one Picaxe 18M2 chip ?
  
  http://www.rev-ed.co.uk/docs/picaxe18m2.pdf
  
  thanks for your help.

  Posted by paul1823 on February 01, 2011 at 18:35:52 Pacific Time