[Solved] 12V RGB LED Strip

Need Help With My Project
1

Hi,

I have managed to set up an RGB single LED with Blynk and I am able to control individual RGB colours using the app, however I wish to use it for a complete 5m roll of 12V LED strip. I realise the Arduino can only supply 5V and that is why I have an external supply unit with a DC power jack. I can get the strip to work directly with the power supply but I am not sure how to wire this with the arduino on the breadboard. I don’t wish to cut up the strip yet. The strip has a 4pin connector at the end that fits into the breadboard and works on the breadboard with the external supply. The 4pins are +12V, Green, Red, Blue. The single RGB LED that I used in the first place had a GND, R, G, B pins, so I simply connected R,G,B to individual pins on the arduino and the GND to the GND on the arduino, I’m assuming the + was coming from the R,G,B pins. Since this strip has +12V, I’m assuming each of the colour pins R,G,B must be GND. How do I go about connecting it?

2

In the specs of the strip you can see wether it’s a common anode of common cathode strip. Most strips use + on the color and a common ground. Since the pins are labeled that way, it must go for your strip too.

What you need is a 12v LED driver, otherwise you’ll fry your Arduino. You could do with a simple MOSFET I guess. Here is some info: http://joost.damad.be/2012/09/dimming-12v-led-strip-with-mosfet-and.html

This come pre-made: http://www.dx.com/p/full-color-rgb-led-strip-driver-module-for-arduino-blue-black-314667#.VoWv2TbSxE4 but I have absolutely no idea if it supports PWM for all three different RGB channels, it says so, but I’m not sure how.

1 Like
3

I had a few IRLZ44N MOSFETs laying around and using an adafruit link(https://learn.adafruit.com/rgb-led-strips/usage) and 3 of the MOSFETs, it works perfectly now. Thanks for the help.

For anyone reading this later on, the adafruit link has the +12V of the LED Strip connected to a 9V header on the arduino which doesn’t exist, it is referring to the Vin port which is linked to the voltage of the power adaptor connected in the barrel shaped connector.

4

There are quite a few ways to use Blynk to drive an RGB strip… it all depends on the hardware you have and the libraries you are using…

For Example…

1)Are the strips 5050’s (not individually addressable) or are they like the NeoPixel’s where you can address each LED individually

  1. what RGB controller are you using (for the NeoPixles you don’t need a board but the code you use for driving them is very timing sensitive)

  2. what language is the controller drive in (python, c, etc)

Here what I used for mine:

  1. 5050 LED strip
  2. Strip LED Driver (Based on the P9813, similiar to a shift register) http://www.dx.com/p/full-color-rgb-led-strip-driver-module-for-arduino-blue-black-314667#.VonDInUrLPE
  3. Python Driver for the LED strip (before I found out about blynk)
  4. Blynk on RPi with Node (“wrapper” which calls the python via command line… I’ll rewrite the led drive in node once I learn it a bit better)
5

I have created project according to these instructions http://www.instructables.com/id/PWM-an-RGB-LED-Strip-with-Arduino/ using wemos d1 mini and single 12v power source for arduino and led strip.

In code I have been using stripped down code only for wifi connection and OTA (I might add virtual ports, now I am using digital ports directly) and in blynk for this project only zergba widget. But I have one maybe stupid problem… How can I switch led strip off via blynk?? In widget there is no such option…