Arduino to control my computer leds

This is my first official arduino project. Just got through the first kit. I'd like to ensure viability that the arduino will run okay powering and controlling up to 20 led majority of the day over many days. The led are 20ma 3v. I'll be using a potentiometer as well. I'll likely pick up an arduino mini for this. I'll be using the 5v current on the arduino and using resistors. I'm just curious of any suggestions and other details I should consider.

Consider the maximum current for the power rails of the chip you are using. If you have 20mA per LED and 20 LEDs that is 400mA, more than you should be supplying with many chips.

So, would an led driver be necessary for this project? I saw them on Amazon and a few other sites s for around 25$. Though I'm not sure it would be cost effective spending on that and an arduino mini and leds. Might be best going with something else for the general case leds and just making an led matrix for smaller purposes?

What would buying an led driver and such yield for additional options? Considering cost would it be ideal for me to just get a pre-made matrix?

In which case I'll need electronic advice as to wiring the led straight to a molex connector. 12v current goes through them. I'd imagine 20 led won't be an issue?

What sort of LED driver? You would need one for each LED.

You need a buffer chip Like the uln2003, that will drive eight LEDs, or you could use a shift register. You could use an led drives chip like the TLC 5940 so you can dimm each individual one. Or you can put $0.10 transistors on each one. Or you could multiplex or charleyplex them.

There are lots of solutions.

Hi, tell us more about these leds and what you want them to do. What have you purchased so far? Include links to the spec of anything important.

With an Arduino Mini you will need a usb to serial adaptor.

Have you considered ws2812b leds? You can daisy chain them on 3 wires and control the colour and brightness of each separately. No drivers needed, they are built in.

http://www.ebay.co.uk/itm/20-RGB-LED-WS2812B-Individually-Addressable-NeoPixel-w-Heatsink-PCB-DC5V-Input-/121452061867?pt=UK_Light_Bulbs&hash=item1c471b64ab

Stick to using the 5V supply in the pc rather than the 12 .

Paul

Ubernewb: So, would an led driver be necessary for this project? I saw them on Amazon and a few other sites s for around 25$. Though I'm not sure it would be cost effective spending on that and an arduino mini and leds. Might be best going with something else for the general case leds and just making an led matrix for smaller purposes?

What would buying an led driver and such yield for additional options? Considering cost would it be ideal for me to just get a pre-made matrix?

In which case I'll need electronic advice as to wiring the led straight to a molex connector. 12v current goes through them. I'd imagine 20 led won't be an issue?

Here I have an example where a single arduino is driving 4 times 8 is 32 LEDs, but in that case all digital lines are used. As long as you stay under the max rating per digital pin there shouldn't be any problem.

http://ejo60.wordpress.com/2014/10/18/seven-segment-led-vintage-component-ir-thermometer/

The magical buzz word is perhaps, multiplexing.

The magical buzz word is perhaps, multiplexing.

Which was mentioned in reply #3

Grumpy_Mike:

The magical buzz word is perhaps, multiplexing.

Which was mentioned in reply #3

And there are numerous alternative ways on how you can implement multiplexing, your arduino uno can do it, a maxim 7219cng can do it, a 74HC595 could be your friend if you need more output lines and a 74HC165 if you need more input lines. And there should be at least a few dozen other possibilities, like getting a 2560 that has more digital lines.

http://www.maximintegrated.com/en/products/power/display-power-control/MAX7219.html
http://www.nxp.com/documents/data_sheet/74HC_HCT595.pdf
http://www.nxp.com/documents/data_sheet/74HC_HCT165.pdf

ejo60: like getting a 2560 that has more lines

An Arduino Mega... for 20 leds? Ejo60, please control your enthusiasm, its great to see, but this is Ubernewb's first project and he/she needs us to keep our feet on the ground, or we will be more of a hindrance than a help.

controlled enthusiasm on 8)

http://www.amazon.com/dp/B0068JYK0I/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=27ILMLF5H1UZI&coliid=I3EVYFLG7ZCTG7

This is what I was considering.

But, as I’ve realized it’s simply more cost effective for me to buy the NZXT HUE. I’ll go that route. I was hoping I could build the entire led array this way. But, the only way this would be cost effective is if I had “more” of the Arduino being utilized. By which I mean if and I likely will add an LED matrix to a small part I may need an Arduino setup like this. But, I’m sure there are cheaper means than buying an Arduino and an led driver like the above for a simple matrix.

The matrix will be covering 3" wide by about 6-8" length of space. It doesn’t need to be super fancy of course. But, definitely RGB.

Is the controller I linked above any good? Or is that completely different from the “standard”?

Thanks to everyone for the replies.

So, perhaps some suggestions for your ideas on what an Arduino can accomplish in this task I have. Keep in mind I’m actually modifying a G5 apple case.
There will be a window and I will be using the original cpu cover. I’ll modify the cover itself to hold the LED matrix. It’s primary phrase will be “converted” or “modified” on the top layer and on the bottom it’ll read “G5”.
Given using the matrix colors and such are adjustable. Maybe eventually I can modify the matrix to give me temperature readouts? Have an entire LCD panel worked in for temperatures that the Arduino manages? Various things the arduino can do “better” than a lot of the options I have is generally what I’m looking for it’s purpose.

This is what I was considering.

I have had bad experiences with one of those, refusing to work.

But, definitely RGB.

First time you mentioned that. It helps to state from the start what you want.

If you want 20 RGB LEDs this is like having 60 normal ones. It changes the answers.