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[on:]

We just started using arduino in college.
For a project my friend and I want to be able to control a string of led's.
How can we use the led's without being directly connected to an arduino and breadboard?
Aslo how would 50 led's be powered?

[Reply #1 on:]

If you want a really detailed answer, you will need to be a lot more specific, you should include all the info you can about the parts (like the part numbers, and datasheets for the parts, does the string use LED drivers? What LEDs, an what are their voltage and current ratings? are the drivers supported on the arduino?

You may want to start with a small project, like a little matrix or cube, to learn about multiplexing and charlieplexing.

You could use wifi or bluetooth, or maybe IR to send data if you can not physically connect the arduino to the LEDs, but that will require a lot more hardware, and bring the cost and complexity (difficulty) up quite a lot, which is probably too much for your first project.

[Reply #2 on:]

Hey I'm also doing this project .. we have 50 leds, 2 Arduino boards and a web cam that we want to control the led's with.We have like 50 resistors aswell and loads of chipsets available to us through our college .Were basically looking for the best way to wire up the project ,we've never soldered before but are prepared to do that as were using solderless board before

[Reply #3 on:]

We just started using arduino in college.
For a project my friend and I want to be able to control a string of led's.

What do you mean by "control"? What do you mean by "string"?

How can we use the led's without being directly connected to an arduino and breadboard?

What do you mean by "use the leds"?

The first step towards getting answers is to ask good questions.

Aslo how would 50 led's be powered?

With a power supply.

[Reply #4 on:]

What do you mean by best. its like the shortcut question, which is the better shortcut, the one that takes less time, or takes less distance. If are specific, its easier to help.

Based on the info you have provided, I can only guess that the best way to hook up the LEDs is whatever way you might learn the most (since this is a school project). That is about as specific as can be, with the info provided.

You may want to look at one of the ambilight projects, they do something similar to what you want, you may be able to adapt to suit your needs.

https://en.wikipedia.org/wiki/Ambilight

[Reply #5 on:]

We just started using arduino in college.
For a project my friend and I want to be able to control a string of led's.

What do you mean by "control"? What do you mean by "string"?

How can we use the led's without being directly connected to an arduino and breadboard?

What do you mean by "use the leds"?

The first step towards getting answers is to ask good questions.

Aslo how would 50 led's be powered?

With a power supply.

Granted the OP was a little ambiguous in his question but I don't think that warranted such a condescending post.

[Reply #6 on:]

You may find some inspiration in this open source project:
http://shop.evilmadscientist.com/productsmenu/tinykitlist/157

[Reply #7 on:]

You might want to look at addressable RGB LEDs found here http://www.adafruit.com/products/306
 or if you search on LPD8806 you will find the same LEDs from different suppliers. There is also a library for programing them found here https://github.com/adafruit/LPD8806  With this setup the data wires are connected to the Arduino and the power is connected to a separate battery of the correct size. You can't power the LEDs from the Arduino as it draws too much amperage and it will cook your Arduino. This is another library that will drive the LEDs from the SPI bus. https://github.com/cjbaar/LPD8806. Good luck.

[Reply #8 on:]

Do you want to control the brightness as well as if they are on or off?

Basically you need a system that distributes the control over the length of the strip, with a control signal passing out of one control chip ind into the next. There are lots of ways to do this. There are specialised chips like the WS2801 or you can use power shift registers like the TPIC6B595.
This gives a good overview:-
http://www.elcojacobs.com/shiftpwm/

[Reply #9 on:]

Some years ago I made a small project using 12 LED powered on 4 pin on a PIC.
Now I'm making a bigger library for Arduino in order to contol, using N pin and POV, Nx(N-1) LED. I made a 90 led pannel (15x6) driven by 10 pin. Excepting for N resistors and N diodes, no extra hardware is required.
Now I'll try to make a 3 wire interface and test this library. I'll put here a link when finished.

Not yet finished... here http://arduino.cc/forum/index.php/topic,134577.msg1011968.html#msg1011968