stand alone

ok, i want to make my daughter an animated image she cab hang on her wall.. the thing is - not going to tie up my son's arduino to it..

it would be like 50 leds NON RGB... regular single colors..

how do i have it as a stand alone thing run by batteries? so many things we buy, that you just pop in batteries to run them.. i want the same kinda thing in the end.

i know you need a chip.. but how is all done? they don't put boarduinos in the stuff we buy at the stores.. so, i'm curious.

thanks in advance

You need a stand alone Arduino.

I have made several.

yes some 'flavor' of standalone Arduino circuit will work.. (usually under $9.00 USD) :slight_smile:

and then of course.. you'll need some sort of 'driver chip' for all those leds.

1.) 50 leds is too many for the Ardiuno to control by itself..
2.) 50 leds will need more current than the Arduino can provide as well..

I suggest using a MAX7219/MAX7221 chip...

it can control/drive up to 64 individual leds or 8 x 8-segment displays..

I do NOT believe it has support for PWM (although it does give you 15 levels if 'intensity' to play with..

There is a lot of documentation and tutorials on using the MAX chips to control many LED..and a library for it as well..

good luck!

Somebody has made an Arduino clone with integrated shift registers (perhaps more than one person has done it). That would be ideal to control your LED matrix. I'm not sure, but I have an idea Crossroads mentioned something of the sort a while back. Maybe it wasn't him, but it was definitely one of the active members on this board.

maybe this will help..what makes things like these run...

sure not arduino... but you can program a chip do perform the same thing and give it a power source (batteries or electric cord)..

keep in mind, some of these are animated - which is what i want to do in the end.. otherwise it's plain just being lit, and not very fun to make for that matter..

something like this? a runtime board?

as for PWM.. there are lots of PWM chips on ebay..pwm for sale | eBay

Come up the layout you want, how many colors, what each color is to do etc. Your request is too vague.
In the example shown, I see 6 colors. No idea of what if anything changes on it.
So that could be as simple as LEDs stuck thru cardboard with strings of LEDs (3-4-5 or so powered by a 12v source), with as many strings in parallel as needed to complete the picture.
Want them to turn on/off in sequence or something? Then a standalone '328P controlling transistors, can create that sequence. If the pins are PWM-able, then you can have easy brightness control as well.

they are your average basic led signs if you will.. some have text, some have a pic, some are animated pics.. some with text and pic (animated/non-animated)


umm.. small butterfly or something small to start off with.. animated.. like the wings are moving - (so ofcourse there will be color changes or just on/off).. i don't know exactly how many leds.. thinking 50... 4-5 colors, in a picture frame kinda thing.. run by batteries (some projects will run by power cord to the wall) - no arduino or usb support in the end..

possibly be able to recode the chip for another image display instead of a butterfly if she wanted something else showing (i just need to be able to control each led individually if i wanted to and especially if i planned on using RGB leds).. again, i can solder, so i don't mind building - i just need to know the exact parts and how many (ie:pwm chips, reisitors.. whatever else needed)...

i'll be less of a pain once i get the chips and such figured out.. and do a couple of those lil projects.. lol

Ok, so you've got vague this, vague, that, unknown # of LEDs/colors, unknown shapes, unknown what is on/off & when, or for how long, unspecified battery voltage & current capacity, etc.
Make some decisions, start firming things up.
Ex: Battery will be this:

LEDs will be these colors, arranged in strings driven from 12V, with multiple strings in parallel:
5mm Extra Bright Red, Green, Blue, Yellow, White

Strings will be switched on using these N-channel MOSFETs

Designs will be built up on these boards


i honestly couldn't tell you "exactly" how many leds it takes to build a small butterfly.. can anyone? so i'm basing it on 50 leds (otherwise i would have to have a bunch of leds and put them together and then count them).. i can't tell you which ones will be on/off until it's built.. all i can say is part of the wings will be on/off.. roughly 2 seconds? yes, ofcourse it will be built on a perf board (kinda thought that was a given.. not a redneck here using cardboard or styrofoam).. and i said 4-5 colors, i don't know which ones atm, whatever looks good.. could be blue, could be pink.. who knows - i don't think color has too much to do with anything honestly.. sure some are brighter than others.. but for this they'll all be 10mm and all have the same amt of current.

batteries are more like.. 9v's or AA's or AAA's.. not a power pack.. like a hang up wall clock, pop in the batteries an watch it go.. at this point, also thinking an on/off button would be a good thing too..

i honestly couldn't tell you "exactly" how many leds it takes to build a small butterfly.. can anyone?

Here is a web page of a butterfly my wife bought.

keep in mind the size of those beads and spacing.. too small and too close.. not the same with leds.

bigger and more spacing = less leds vs those beads

something like this (sorta).. best visual i have atm..
52 here? just for the butterfly..

ok, so this one has more than 50..