Powering 32x64 Matrix with a USB power bank

I am investigating on powering one RGB LED matrix panel with a 10k mAh powerbank, in a portable fashion only. I plan to have the following items:

  1. 10k mAh 2 x 2A 5V USB-A powerbank -- USB Battery Pack for Raspberry Pi - 10000mAh - 2 x 5V outputs : ID 1566 : $39.95 : Adafruit Industries, Unique & fun DIY electronics and kits
  2. USB-A to 2.1mm Male Barrel Jack Cable 22AWG & 1 meter -- USB to 2.1mm Male Barrel Jack Cable [22AWG & 1 meter] : ID 2697 : $2.75 : Adafruit Industries, Unique & fun DIY electronics and kits
  3. Female DC Power adapter - 2.1mm jack to screw +/- terminal block -- Female DC Power adapter - 2.1mm jack to screw terminal block : ID 368 : $2.00 : Adafruit Industries, Unique & fun DIY electronics and kits
  4. 4mm Pitch 4-pin power cable. Terminated with both a female polarized connector, and a pair of spade terminals. I was thinking that I can get rid of the spade connectors here though.
  5. RGB 32x64 LED Matrix Panel 3mm pixel pitch 5v 6124 chip - I can provide full panel specs if needed
  6. Arduino Mega2560

Here is my plan on the workflow, referencing the items above by number listed:

1 (powerbank) -> 2 -> 3 -> 4 (feed +/- wires directly into the +/- terminal block, instead of spade connectors) -> 5 (led panel) -> 6 (mega)

The panel has a 16-pin (IDC connector). To my understanding, this will be providing the common ground needed, when plugged from panel to the Mega, after viewing the hookup table. I am planning on powering the Mega with a separate portable power supply via DC power jack. I plan for this other portable power supply to be a 9v battery holder w/ 2.1mm plug or 8xAA battery holder w/ 2.1mmm plug, to not complicate things for myself with the other circuit for the matrix.

This is to be used in a low/no light environment. I am expecting to just have some text scrolling with low brightness and avoiding white illumination. This is why I believe I would be "okay" with just a 2A output power supply. I figured that I would need to maybe look into doing a series/parallel setup of power banks going this route, as there are so many pixels in this display. I would like to have this on for at least a few hours at a time, but right now I am just concerned if this would be feasible and relatively being a safe way to achieve this. I don't plan on using this inside of a building btw, which is why I am trying to achieve this portably.

FWIW to anyone, I am just trying to learn more about hardware (played around with ws2812b in the past), coding in C, and have something cool to display afterwards (e.g. on a flag pole at a campsite or something). Ideally, I will switch it over to being powered via wired so that I can enjoy my project at home and try to grow the project so that I can learn more about wifi / bluetooth modules, etc...

What challenges will I face with this presented workflow because of multiple adapters being used in conjunction? I am worried about needing beefier and shorter cables so that I can prevent power drop, and heating issues of components and wires (mainly the powerbank). I'd like to just try out my current approach presented above to test, but am high key worried about hardware issues - stuff melting and blowing up on me. I am still looking into the math of things like calculating power drop/resistance/AWG max currents at this time, but could use some help in the right direction to ensure I am on the right path. Prior investigation has shown me this should be okay... I am not using a breadboard and homemade power supply (reliability issues). Thank you all.

That large a panel is going to pull ~8A peak and ~4A average. That's 40W on the +5 line. 22AWG is going to get HOT and/or melt. Peak on 22 ga is ~1A. You'll need 16 ga on the Vcc and Gnd leads minimum. That cute barrel connector will FUSE. My 32x8 matrix pulls over 1/2A on the ammeter at full brightness with typical (50% pixels lit) message. Your draw will be 8x that.



if the 25W Module Consumption is to be taken as maximum power consumed when all LEDs are turned on at once.. does this not mean each individual LED only uses 2.44mA?

Sparkfun says that it uses 4A in the worst case here: RGB LED Matrix Panel - 32x64 - COM-14718 - SparkFun Electronics


The matrix will consume a maximum of 5Amps.
It doesn't mean each LED consumes 2.44mA, the display is multiplexed and it strobes the LEDs in the display so they briefly flash on and off, it is done so fast the human eye does not notice the flicker.

Not knowing the specs of the individual LEDs it will be hard to find out.
By the way it is RGB so 32 x 64 x 3 = 6144 LEDs.

Please post a link to specs/data.

Thanks.. Tom... :smiley: :+1: :coffee: :australia:

Thanks, this is helpful information. I have noticed that my camera can capture the flicker, haha so this makes sense. I do not have a link to the specs, as I bought the panel a long time ago on an amazon account I do not have access to anymore. I did however, keep a text file of specs. It seems I was given the exact bundle of items that are in that sparkfun tutorial I linked above (from what I can tell at least).

I have tested it using a wired power supply that I have (5v 2a), in fact, I have tested it wired to another 32x64 (two displays chained), and it worked fine for the ~15 mins I left it on (not full brightness, not all pixels lit, did not test with multi meter as I am still learning how to do that). I bought these a while back and got the second one in case the first (main one I will be using) ended up burning out or something. I don't plan on chaining them right now but maybe in the future if I want to expand the project after having success with one display. I bought it off some random vendor on Amazon for very cheap, here is what I was given:

dear buyers, This panel comes with 6124 chip, it could fit for most of software like ardiuno, rasberry pi, if you have any questions about how to display it, please contact us by message, we will try our best to help you, Please don't return the item to amazon warehouse or leave negative feedback/ review before contacting us if you don't know how to drive this panel, thank you!
If you had issues getting these to work with scripts, please get great info on github on how to get these working perfectly and people is updating their code to have them working out of the box! Ask for your kind understanding!

here is datasheet about P3
Module: P3 Full Color LED Module
 Pixel type: Real pixel
 Pixel pitch: 3 mm
 refresh frequency : >=400HZ
 Module Size: 192X96 mm
 Horizontal View Angel: > 110 degree
 Model Pixel: 64X32 Pixels
 Working Environment: Temp:-30 ? ~60 ?
Humidity : 10%-90%
 lattice density 
111111 dots/square meter
 Working voltage: 5V
 Pixel form: 1R1PG1GB SMD2121
 Lifetime: >=100000 hours 
 Best viewing distance: 3m~30 m
 Gray scale: 12 bit/ 1 color
 Max power consumption: 1400W/square meter
 Color display: manual adjust
 Ave power consumption: 600W/square meter
 Brightness: 2200 cd/square meter
 warranty: 3 year
 Blind spot rate: <0.00001
 Drive mode( Optional)
Constant current 1/16 scan 
 Waterproof Class: IP43
Control system: DVI card+Full color control card
Support window series system

Package include:
1x P3 led matrix module
1x power cable
1x data cable
4x magnetic screws

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.