Hello everyone, I need advice to make my led strip light up and start using FastLED.
What I have:
Arduino Uno R3
WS2812B LED strip (150 pixels)
Breadboard with MB102 power supply
Jumpers Male to Male
Some resistors that I don’t know how much ohm
I have tried to follow these tutorials:
Of course, I don’t have the exact same components, but I wonder if there’s a way to make my LED strip light up still, and so I can start using FastLED.
If there’s something I absolutely need, please tell me, I will try to get it.
Thanks in advance, I’m new to electronic but willing to learn.
P.S: I was able to light up a Clear Red l.e.d with Arduino.
The power supply MB102 seems to work, and burn one of my Clear Red l.e.d
You have everything on hand to light-up your LEDS with FastLED
The biggest problem I see is that you do not have a big enough power supply for 150 LEDS. I suggest a 5V power supply that can output 10 amps. On eBay you can buy one for about $20 CDN.
A full brightness white WS2812 LED requires about 50 milliamps each so a total of 7.5 amps for 150 LEDs. That little wall supply (only 3 amps MAX!) will not be able to drive all these LEDs in that circumstance.
That should not stop you from starting with fewer LEDs at a reduced brightness to play with some basic sketches.
Another very useful thing to have is a simple multimeter that can measure voltage, current and resistance. You can also find cheap ones on eBay for $20 CDN.
With the stuff you currently have the basic setup would look like this:
Data line comes from UNO pin 11, through resistor, and then to strip.
The ground from the UNO must be connected with the external power supply’s ground.
You can lookup resistor values with a site like this or use a multimeter. http://www.dannyg.com/examples/res2/resistor.htm
If you don’t have a multimeter definitely get one as JP suggested. Very useful to confirm and test things when wiring projects up.
Did you burn >out< one of your clear red LEDs?
That’s FastLED unrelated, but if you want to lit up an LED you have to calculate a Resistor (in series). You need to know the Source voltage (5V) and the LED forward voltage. You can find this in the datasheet but for a red LED 2V is save. Then you need to know how much current the led can take, most of them can handle 20 milli Ampere = 0,02A. (That’s also about the max one Arduino pin can drive).
Enter it in the calculator http://www.ohmslawcalculator.com/led-resistor-calculator
and voilà you know that minimum a 150 Ohm resistor is needed.
If you attach an LED without resistor it will burn out in an instance AND can damage your Arduino.
Before you dive into FastLED it would be a good idea to get acquainted with Arduino and electronics basics.
For a beginner I can highly recommend @Jeremy_Blum 's Tutorial Series that give you ton’s of insight to the Arduino world and you can create your own sketches later on. (Btw, his book is awesome as well.)
Thanks @Juergen_Bruegl I will try to get those
I wonder if you can recommend a resistor kit that contains various resistor for Arduino project in general? Also, should I get such kit for capacitor?
I was thinking to order these valuepacks from this website: http://www.futurlec.com/ValuePacks.shtml
Perfect, with all these kits, I should be able to light up my LED strip and hopefully work on many project. One I’m dreaming of is some kind of disco mat or disco floor for the kids
This you can get easily at your local hardware store or recycle and old PC power cord. Nothing special about that cord just 3-wire AC cord with a standard AC plug at the end !!!
I think it is best to get a different PSU for each new project. For each project you need to calculate the maximum current that will be required and then increase that amount slightly.
For example you were talking about 150 WS2812 LEDs in your project. You MUST understand that each pixel can draw 50 milliamps. When you multiply that by 150 you get 7.5 amps. That is why I recommend a 10 amps PSU. I prefer to always get more than required.
Also very critical is to understand that WS2812 LEDS work with 5Vdc not 3V and definitely not 12 V !!!
There is nothing wrong with choosing a 20 amps PSU instead of a 10 amps. It is ok to have more amps available but NOT LESS !!!
Something else to consider is that a PSU with more amps is always bigger and take more space and that sometimes is a problem when you want to fit your whole project in a smaller enclosure !!
And this is the corresponding panel mount socket if you think of making a box that contains all the electronics of your project…
Note that you may not need that socket as you can simply cut the cable near the connector, strip the insulation of the 3 wires and connect directly to the screw style terminal strip of the Power supply.
