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Akali Mask - 54 x APA102 LEDs on portable power source
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Akali Mask - 54 x APA102 LEDs on portable power source

by stephaneag on Mon Feb 04, 2019 5:35 pm

Hi there !

I'm currently looking for the best way to power 54 x APA102C LEDs from a portable power source.
I plan on using a PowerBoost 1000C booster/charger to power both the uC ( either arduino uno pro or Espruino ) and the LEDs, which 'll be at their brightest & "fully on" on their R,G & B channels for at least 1 minute, switching patterns every few ms in a synchronized manner.

I started with using a PowerBoost 500 booster/charger + a "supposedly 12000 mAh" 3.7 ICR18650 ( before reading more on that scam & finding about the 3600mAh maximum .. ), but I'm not sure if even other batteries 'll be able to provide the required current discharge ( 60mA * 54 LEDs 'd mean 3.5A power source ), or if I need to use two boosters + single battery, or two boosters & 2 batteries, or even directly a 5V power bank ( ex: https://www.adafruit.com/product/1566 )

iyo, what 'd be the best way to provide the needs to such power hungry setup ?

ps: in case the subject is of any further interest to anyone, this is for a Cosplay part ( "Akali's mask" ) and the goal is to provide synchronized transitions between ~hollow leds segments ( see the entire thread & some somewhat-dirty poc code at the following link: http://forum.espruino.com/conversations/330092/)

This being said, wishing the reading a nice evening of coooode ;)
Thanks in advance ++

stephaneag
 
Posts: 46
Joined: Sat Mar 29, 2014 8:37 pm

Re: Akali Mask - 54 x APA102 LEDs on portable power source

by adafruit_support_bill on Mon Feb 04, 2019 5:44 pm

I'd forget about voltage boosting and associated limitations and inefficiencies. You are better off powering both processor and pixels direct from your battery pack. We regularly run Neopixels and Dotstars directly from 3.7v LiPos. They also work well with 4.8v NiMH packs or 4.5v Alkaline packs.

adafruit_support_bill
 
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Joined: Sat Feb 07, 2009 10:11 am

Re: Akali Mask - 54 x APA102 LEDs on portable power source

by stephaneag on Tue Feb 19, 2019 6:27 am

Hi there !

Sorry for the delayed answer :/ ...

Thank you very much for the hint: it seems to work quite well for ~45 daisy-chained leds :) ( I drive those using either an Espruino original or a Trinket pro 3V ;p )
Also, I had to digg deeper into the ATmega328 datasheet to get a better grasp on Timers & Interrupts -> lot of potential but not that simple to grasp at first .. ( and it seems there are some tiny errors in it .. I guess the Atmel guys are just "normal humans" when redacting 294 pages of docs ;p ... )

stephaneag
 
Posts: 46
Joined: Sat Mar 29, 2014 8:37 pm

Please be positive and constructive with your questions and comments.