How much power does it take to run a Gemma M0/NeoPixels?

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jharris1993
 
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How much power does it take to run a Gemma M0/NeoPixels?

Post by jharris1993 »

Greetings!

As anyone who has followed my ramblings will know, I'm working on a NeoPixel project that uses the Gemma M0 as the controller.

One question I had, and have seen, is "how much power does it take to run a [insert name here]?

First, I highly recommend reading this tutorial on getting the maximum amount of light with the minimum amount of battery.
https://learn.adafruit.com/sipping-power-with-neopixels

Here is the results of some testing I did with my project.

Given:
A Gemma M0, running in "Arduino" mode - not running Circuit Python.
It's running the "Demo Reel" demo from within the FastLED library for the Arduino.
It's set to run an entire one-meter string of 60 NeoPixels at about half-power, (almost full brightness but using only half the juice - see the article above.)

I tried running it off of a bunch of bizarro power sources, including a single 2032 3v coin cell battery. Silly, but I wanted to try it just for Grins and Giggles.

The Gemma M0, driving 60 NeoPixels, ran wonderfully off of the coin-cell battery! Nice and bright, all programmed functionality - including capacitive touch-pads - working as expected. Of course, the coin-cell didn't last long - about 20-30 minutes max - but it continued to run down to a measured voltage of 2.5v or thereabouts. Dim? Yes. Running? Absolutely!

After this, I'd seriously consider running a small, battery-powered project off of a 2047/2051 battery - about 2x the thickness of a 2032 - and would expect a several hour run-time.

Interesting!

Jim "JR"

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adafruit_support_bill
 
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Re: How much power does it take to run a Gemma M0/NeoPixels?

Post by adafruit_support_bill »

Cool! That's more than I would have expected from a coin-cell powering that many pixels. Thanks for posting your findings. :)

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jharris1993
 
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Re: How much power does it take to run a Gemma M0/NeoPixels?

Post by jharris1993 »

adafruit_support_bill wrote:Cool! That's more than I would have expected from a coin-cell powering that many pixels. Thanks for posting your findings. :)
You're quite welcome!

To clarify something, the Gemma M0/NeoPixels didn't stop working at 2.5 volts, I just stopped monitoring and disconnected power. At 2.5 volts, I figured I was pushing my luck and chickened out.

Especially if you're doing something that didn't require NeoPixel class loads, I don't know how long the Gemma would go before crapping-out. Though at some point, substrate leakage currents would have to become enough of an issue to cause erratic behavior.

If you guys decide to send me a bunch of Gemma M0's and a handful of meters of NeoPixels, I'll be glad to experiment and report my findings! (laughing!)

Jim "JR"

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