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Topic: any shield for a ton of RGBs? (Read 4544 times) previous topic - next topic

juanmol

Hi, i need to control almost 100 RGB led. I don't need a lot of colours/steps in each led, only 16 color each, or less. There are a shield o a board reaady to connect?

edit: i forgot to say i need to control with a new arduino, recomend me too, a arduino mega?

Grumpy_Mike

1 shield driving 100 RGB LEDs - no.
Think about it, it would have to be very large or take a large amount of current.
You can have several interfaces chained together like the blinkM
http://thingm.com/products/blinkm

Or you can chain together shift registers like this:-
http://www.elcojacobs.com/using-shiftpwm-to-control-rgb-leds-with-arduino/

fungus


Hi, i need to control almost 100 RGB led. I don't need a lot of colours/steps in each led, only 16 color each, or less. There are a shield o a board reaady to connect?

edit: i forgot to say i need to control with a new arduino, recomend me too, a arduino mega?


How are the LEDs arranged? In a matrix, in a cube, spread around a room...?

Advanced Arduino

juanmol



Hi, i need to control almost 100 RGB led. I don't need a lot of colours/steps in each led, only 16 color each, or less. There are a shield o a board reaady to connect?

edit: i forgot to say i need to control with a new arduino, recomend me too, a arduino mega?


How are the LEDs arranged? In a matrix, in a cube, spread around a room...?




at the end of a long (between 1 and 6 meters) wire, each one. No matrix, no board or similar.

juanmol


1 shield driving 100 RGB LEDs - no.
Think about it, it would have to be very large or take a large amount of current.
You can have several interfaces chained together like the blinkM
http://thingm.com/products/blinkm

Or you can chain together shift registers like this:-
http://www.elcojacobs.com/using-shiftpwm-to-control-rgb-leds-with-arduino/


the second one is interesting. How many 74HC595 may i connect to an arduino mega? How many RGB leds?

fungus


How many 74HC595 may i connect to an arduino mega? How many RGB leds?


There's no real limit. And you don't even need a Mega.

Advanced Arduino

juanmol

maybe 74HC595 is small for me, i need more RGB leds for each chip. I need other kind of multiplexer, any recomendation?

fungus


maybe 74HC595 is small for me, i need more RGB leds for each chip. I need other kind of multiplexer, any recomendation?


Can you pass wires from LED to LED in a big long string? If so then get one of these http://www.ebay.com/itm/160907739909 and cut it into individual LEDs.

If not, you'll need four wires to each LED from a central PCB. That's an awful lot of wire (two or three kilometers if my calculations are correct... :) )

Advanced Arduino

juanmol



maybe 74HC595 is small for me, i need more RGB leds for each chip. I need other kind of multiplexer, any recomendation?


Can you pass wires from LED to LED in a big long string? If so then get one of these http://www.ebay.com/itm/160907739909 and cut it into individual LEDs.

If not, you'll need four wires to each LED from a central PCB. That's an awful lot of wire (two or three kilometers if my calculations are correct... :) )




my first idea is the 3+1 wires for each one, the addressable strip is very interesting, how i conect it to the Arduino?

juanmol

can anyone recomend me addressable led strips to cut one-by-one to extend and separate the leds?
And I have a question, how i asign an address to a led??

Grumpy_Mike


can anyone recomend me addressable led strips to cut one-by-one to extend and separate the leds?
And I have a question, how i asign an address to a led??

I think you are way out of your depth on this one. This is a massive project and putting 100 RGB LEDs on the end of 6 meter wires is something I would not attempt to do myself.
Electronics, like most things, becomes more difficult as you scale it up. Things that do not matter at low currents / distances become limiting factors with large currents / large distances. I am not saying it can't be done but I am saying it will take either a lot more skill than you have or a lot more money than you would like to spend.

Do you have a budget for this project or an idea of how much you would like to spend.

fungus

#11
Feb 27, 2013, 05:56 pm Last Edit: Feb 27, 2013, 06:00 pm by fungus Reason: 1

my first idea is the 3+1 wires for each one, the addressable strip is very interesting, how i conect it to the Arduino?


That depends on the strip.

I bought some from this guy a couple of months ago. They work great and he's very helpful:

http://www.ebay.com/itm/160896346789

You can cut LEDs off the end of the strip with scissors and attach them to the previous LED in your project with just three wires.

You only need one Arduino pin to drive an entire string (which can have as many LEDs as you want!)


And I have a question, how i asign an address to a led??


With those strips you have to update all the LEDs in the string up to the LED you want to change.

In reality it's easiest just to update the entire string in one go.

Advanced Arduino

Hippynerd

100 is kind of  a lot. If you go with shift registers, you probably want something more stout than the 595, probably the TPIC shift register.
You could also charliplex, but the additional wire length may make that more difficult.

You may want to do something like serial chip on each LED, but there might be signal issues, with the long wires.

I can easily charlieplex 64 RGB LEDs, using 16 pins (should work on any arduino). 100 would be pushing it...

fungus


I can easily charlieplex 64 RGB LEDs, using 16 pins (should work on any arduino). 100 would be pushing it...


'Easily'?

Charlieplex theory and charlieplex practice are two different things.

How much wire would he need to put each LED 4m from the Arduino? What would be the diameter of the bundle of wires coming out of the Arduino (to the nearest cm)?

What would be the on/off ratio for each LED? How would that affect their brightness? How would you arrange the current-limiting resistors so that R,G and B are equally bright (assuming you actually bother to use any)?

Finally ... (and this is the biggie) ... how would you do PWM?
Advanced Arduino

juanmol



my first idea is the 3+1 wires for each one, the addressable strip is very interesting, how i conect it to the Arduino?


That depends on the strip.

I bought some from this guy a couple of months ago. They work great and he's very helpful:

http://www.ebay.com/itm/160896346789

You can cut LEDs off the end of the strip with scissors and attach them to the previous LED in your project with just three wires.

You only need one Arduino pin to drive an entire string (which can have as many LEDs as you want!)


And I have a question, how i asign an address to a led??


With those strips you have to update all the LEDs in the string up to the LED you want to change.

In reality it's easiest just to update the entire string in one go.




60 leds, 29'95, cut on-by-one and you telling me you've it working on an Arduino, i think we have a winner!

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