PIC USB color changing light


Ian at DIY Life made a nice tutorial video on RGB color mixing with LEDs on the PIC platform. His circuit throws in a handful of extras, like mic input. While perhaps simpler to do on the Arduino with a BlinkM, this project looks like a good PIC starter. His whiteboard circuit diagram drawing lapse is pretty neat, too. – Link.

BlinkM – Link.

DIY ambient orb – Link.

8 thoughts on “PIC USB color changing light

  1. computerwiz_222 says:

    why the capacitors on the 7805 and 7812… I usually just hook it up pin 1 input, pin 2 ground, pin 3 out… Is this for reference to ground, I am fairly new to electronics so please enlighten me!

  2. Becky Stern says:

    You can do that, and it will normally be fine, but sometimes power supplies can be “noisy,” supplying uneven current, so these capacitors, called “decoupling” capacitors, help even out the power: http://en.wikipedia.org/wiki/Decoupling_capacitor

  3. ian says:

    I did the same thing for a long time. One day I took a look at the datasheet for a 7805 and it recommended decoupling caps. I’ve done it ever since. In general, it’s standard practice to put a 0.1uf cap between any IC power pin and ground.

  4. John Honniball says:

    The reason for the capacitors is “because the data sheet says so”, but some people like to break rules like that. In fact, the capacitors are there for a good reason, and it’s not just a ploy by the data sheet writers to sell more capacitors! The 7805 (and similar) regulators contain a high-gain amplifier as well as a voltage reference and a power transistor. The high-gain amp can oscillate under certain circumstances, at a very high frequency. It all depends on the inductance of the supply leads. The capacitors make sure it can’t oscillate, and thus ensure reliable operation.

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Becky Stern is a Content Creator at Autodesk/Instructables, and part time faculty at New York’s School of Visual Arts Products of Design grad program. Making and sharing are her two biggest passions, and she's created hundreds of free online DIY tutorials and videos, mostly about technology and its intersection with crafts. Find her @bekathwia on YouTube/Twitter/Instagram.

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