Gemma/NeoPixel 12 Ring Power Source

Beginners
#1

Hi Everyone,

I am putting together a little light up project with my kids but I am unsure how to best power it to begin with. It will be made up of a Gemma V2 and a Neopixel 12 Ring. From what I can see the Gemma can be powered by anything up to 16 V but I can’t find a lot on the ring. It says hook it up to 5 volts and it is right to go. I was planning on using a 4 cell AA battery holder to being with which will give 6 volts to the Gemma but if I use the Vout pin on the Gemma for the Ring I am worried it will be to higher voltage. Do I need to add in a 5 volt regulator before the ring?

Thanks in advance.

#2

OK, after a bit of further research I am seeing people running them on 3 AA Alkaline batteries giving 4.5 volts. Again, I am still interested in peoples comments on the best way to run this sort of system.

#3

Hi,
I’ve used the Neopixel strips & rings before. They are great.
They work fine on 3.7V to 5.0V
So a 3.7V LiPo battery is fine. So is 4.5V from 3 AA batteries.
But 5.0 V is the upper limit so 6V from 4 AA batteries is a bad idea.

The Neopixel strips are easily damaged by voltage spikes so I’m pretty sure the rings will be too.
Adafruit recommend a capacitor across the power supply near the Neopixels.
This is important… I got lazy once and neglected the capacitor…
connecting & disconnecting the power created a large enough voltage spike to fry the chips.

Also read the Adafruit page on best practices

Hope this is helpful.

#4

Thanks for that. I have gone with the 3 AA batteries at the moment with a large cap (4700uF) which should do the trick according to the best practices site. I will see how it all goes when it arrives!!

#5

Actually, with using 3 AA cells giving 4.5 volts… am I going to need a logic level converter between the Gemma and the Ring?