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Unread 01-12-2015, 01:38
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Greg Needel Greg Needel is offline
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FRC #2848 (All-sparks)
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Re: Neopixels & regulators

The other important thing to remember is what affects current draw. Each led Pixel is made up of 3 small LED dies - Red, Blue, & Green. If you put them on full power each die can draw around 20 mA, so 60mA per pixel max. This does add up, but odds are you are not just going to make an all white strip all the time.

If you do simple things like sweeps of single colors at a 50% duty cycle (which is still very bright), you can actually get away with driving the LED's off the VRM or even just the 12-5v regulator on the RIOduino/ arduino. It is easy to bench test this as you will see the LED's not work as expected and likely the arduino will restart if you pull too much current.

Last season we drove our LEDs directly off the regulator as described, but yes having a 12 to 5v regulator just for LED's is a good idea. The one for the old radio is a good option, but it is also very heavy. I have bought many of these http://www.amazon.com/KEEDOX%C2%AE-C...dp/B00A71CMDU/ They are light, cheap, and work great.



As a side note, while LED's on robots can be awesome looking and add some awesome bling, please keep it within reason. I also challenge teams to use the LEDs on their robots for practical things like indicators for drivers instead of just bling.
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Greg Needel│www.robogreg.com
Co-founder REV Robotics LLC www.REVrobotics.com
2014 FRC World Champions with 254, 469, & 74