Hi. I'm working on my first ever LED project and I'm completely lost. Most tutorials seem to go way over my head and at this point I'm not even sure I've gathered the right materials.
Here's what I want: roughly 6 feet of LED strip to do a slow pulse (like these lights are doing: - YouTube ) JUST in white. And all at the same time. That's it.
Here's the catch: everything needs to fit inside of a clear pipe that has about a 1" diameter opening. I've purchased some 3350mAh USB chargers that fit inside. So ideally I would run the lights on that.
Does anyone have suggestions on what lights and what controller I should buy? And if you know of a code that does that slow pulse, that'd be amazing.
A pro mini will probably fit inside that pipe. Your power source probably won't since you are going to need some amps to drive 6 feet of LEDs. Check out the fastLED library, it is great for controlling lots of LEDs. The type to purchase are SMD 5050 LED on Amazon. They come in 12V or 5V varieties. Either will work and the power supply can drive your arduino as well.
It's hard to tell from that video, but it looks like they are all fading together... No sequencing, right?
A "regular" LED strip has all of the LEDs wired in parallel (so they go on & off and fade all at the same time).
I can't recommend an LED strip, but I do recommend you avoid "cheap suppliers" on eBay, etc. SparkFun and Adafruit are reliable suppliers and they have good documentation, and sometimes example projects.
The Arduino by itself can only power a couple of LEDs. To power & control an LED strip requires a power supply and a [u]MOSFET[/u] or transistor driver circuit. (You can leave-out the diode since you have a non-inductive load).
Most LED strips are 12V and some are 5V. Either way, you can power the Arduino from the same power supply.
The power supply voltage needs to "match" the voltage rating of the LED strip. The Arduino has a built-in 5V voltage regulator so it can run from 7-12V, or it can run from 5V (bypassing the regulator).
The power supply's current rating (Amps or milliamps) should exceed the requirements of the LED strip, plus a bit more for the Arduino. The current for the LED strip may be specified as mA per foot, or mA per LED, so you'll probably have to do some simple calculations.
With the driver circuit you can dim an LED strip the same way you [u]dim/fade[/u] a regular little LED. Note that LEDs require a current-limiting resistor (as shown in the Fade example). LED strips have o one resistor per LED built-in. The difference between a 5V LED strip and a 12V LED strip is the resistor values.
...The video you linked to says "NeoPixels". NeoPixels are special RGB (multicolor) LEDs with an addressable driver for each LED. So, NeoPixels don't require any additional circuitry and you can individually address/control a huge number of LEDs. They are wired/addressed serially so a write to any NeoPixel LED requires the data to pass-through all of the LEDs in front of it in the string. That makes the software rather complicated, but there are libraries to (somewhat) simplify it.
Hm. I haven't been able to find any 5V LED strips that are a single color and done in parallel. You are correct that I don't need them to be individually addressable. I need the entire strip to pulse all together.