Microcontroller power usage

The assignment for this week was to measure the power required to run a microcontroller as a first step towards the solar project. I got this neat usb stick that connects in between your computer and the Arduino and tells you how much power it draws. I started with measuring the Arduino while its idle and not doing or connected to anything (literally uploaded an empty code file to it).

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I moved on to measuring other things — one of them is just a simple time-of-flight distance sensor:

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And then I set out to try measuring the current of something that has different modes. I opted for using a Neopixel ring because I know the brightness and the colors, as well as the amount of lit pixels could be interesting to inspect.

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Some more tests, like measuring how the current changes with the lights' animation cycle.

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This is with just one light, brightness set to 50, and the color set to fully red. On and off makes a difference of just 0.01 amps.

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This is the same, but with the color set to full blue. There's a difference of 0.05 amps between on and off.

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A fully white light with the brightness set to 255 has a difference of 0.16 amps between on and off states.

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And a fully lit, fully white, with full brightness gets us to a whopping 0.174 amps!

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I think it's interesting to note that — obviously there is a correlation between brightness and the power needed to supply it — but while the brightness could be 5 times higher between different settings, the current it draws is only about double...