RGB LED Strip Control Circuit Problems

I have one of the following LED Strips and want to control it with my Arduino Uno.

I’m using the following circuit:

My LED strip looks like above: +,R,G,B

I’m using the following code (I’m only testing on the green pin for now):

#define GREENPIN 6
#define FADESPEED 15     // make this higher to slow down
 
void setup() {
  pinMode(GREENPIN, OUTPUT);
}
 
void loop() {
  int b;
 
  // fade
  for (b = 0; b < 256; b++) { 
    analogWrite(GREENPIN, b);
    delay(FADESPEED);
  } 
}

I get nothing when running the code. I have a 12v/1a power supply plugged into the Arduino. However, If I connect an LED to the circuit the LED functions as intended. Starts dim and get brighter then repeats.

Any thoughts?

How long is your strip? They draw close to 500 mA/foot.

What transistors are you using?

When you test with a stand-alone LED are you connecting through the transistor or direct to the data pin?

  1. I'm testing with a 12 inch strip

  2. I've tried a few, but, I'm using a TP120

  3. LED (+) is connected to 5V on Arduino while (-) is connected to Collector

Thanks for taking the time to help.

Probably, LED strip on 12V.

LED (+) is connected to 5V on Arduino while (-) is connected to Collector

Wire the LED + to the Vin pin and then feed 12V into the arduino's power in jack. Nothing will light up with 12V.

Magician: Probably, LED strip on 12V.

?? It's a 12v LED strip. I tested the power supply that came with it and it's spitting out about 12.3v and I get about 11.8v through the Arduino Vin

Wire the LED + to the Vin pin and then feed 12V into the arduino's power in jack. Nothing will light up with 12V.

Grumpy_Mike:

LED (+) is connected to 5V on Arduino while (-) is connected to Collector

Wire the LED + to the Vin pin and then feed 12V into the arduino's power in jack. Nothing will light up with 12V.

When using the single LED for testing the circuit I connect the LED + to 5v and - to collector of transistor and everything works fine. Then I remove the LED, plug in 12v power supply make the connection from Vin (11.8v) to + on LED STRIP and connect each RGB LED to it's respective collector and nothing happens when running the program.

What happens if your insert green line wire to GND directly?

So as a test use a wire to short out the collector and emitter of the transistor. Does it light up? If so check the ground connector from the board to the arduino.

Next remove the connection of the arduino to the resistor and connect the resistor between the base and 12V. Again it should light, if not are your transistors working?

Basically what you are saying you did is correct, the fact that it is not working means that you do not have it wired like you think it is wired. Solderless bread board is a sod for this sort of thing.

Thanks for the input guys! I will try this out when I make it home.

I ordered a second set of RGB LED Strips from eBay which stated could be controlled by IC.

I hooked them up to my circuit and bam it worked. I have no idea what is up with this set I got from Frys.

Thanks for all the help folks.