How to connect 5v Ultraviolet non-addressable LED to an Arduino Uno?

Using Arduino Project Guidance
1

Hi everyone,

I am new to using the Arduino Uno, but I know that it can help with the project I am working on. I need to create a batter operated UV led strip to place inside a shadow box picture frame. It needs to fade on and run for 10 minutes, and then fade off for 10. (I got the coding figured out already and it is posted below.) I purchased a 2m, 5v Uv LED strip. It has 120 units, the voltage is described as 5 DC volts and 12 watts. I have seen schematics on how to connect it addressable LEDs, but I couldn't find anything on non-addressable 5v LEDs. I am not sure if it needs a resistor, and if it does, I am not sure how many ohms it needs.

When I tested my code briefly (10 second on 10 seconds off) I connected the positive wire from the led to pin 9, and the negative wire to ground, but I am not sure if this is right (or safe). Any advice would help!

Coding:
int ledPin = 9; // LED connected to digital pin 9
void setup() {
}

void loop() {

// fade in from min to max in increments of 5 points:

for (int fadeValue = 0 ; fadeValue <= 255; fadeValue += 5) {

// sets the value (range from 0 to 255):

analogWrite(ledPin, fadeValue);

// wait for 30 milliseconds to see the dimming effect

delay(70);

}

start:delay(10000);

// fade out from max to min in increments of 5 points:

for (int fadeValue = 255 ; fadeValue >= 0; fadeValue -= 5) {

// sets the value (range from 0 to 255):

analogWrite(ledPin, fadeValue);

// wait for 30 milliseconds to see the dimming effect

delay(70);

}
start_2: delay(10000);
}

2

Please post a link to the data sheet containing the missing information.

And include code in Code Tags </>, see the sticky topics on top of the forum.

3

Hi,

Sorry I new to this, so I am to exactly sure if this is what you were asking for. This is the only data sheet I could find. Please let me know if this was not what you meant!

I changed the tag as well.

Thank you

IMG_5308 2
IMG_5308 2828×1084 149 KB

4

This means that the full strip (120 LEDs) takes 2A. Get a logic level MOSFET to switch that current.

I wonder why you want to fade UV LEDs - who will recognize that?

5

I work with a glow in the dark pigment called strontium aluminate mixed with acrylic paint. It glows best when charged with UV light. The gallery that I am installing in wanted the painting's lighting on a timer, but they wanted the lights to fade on and off. That is why I am working with them, and why I needed a programmable microcontroller. Otherwise, I would just use a standard looping timer.

When setting up the MOSFET, is it the same type of setup that you would do with 12v LED strips?

6

For the MOSFET 5V or 12V load does not make a difference.

7

Before you commit to those leds be sure you can fade them. The usual way is to rapidly turn them on and off and change that ratio. Be sure they will function that way.
Paul

8

Thanks Paul. I was able to get them to fade pretty well. Would you suggest I switch to 12v instead?

9

Sure. all else being equal, the wire size will be at least 1/2 the size.
Paul

10

Take care when playing around with uv leds.
There are some wavelengths that can damage eyesight easily.

11

Thank you! I have been looking at FDA fact sheets to know how best to protect my eyes when working with them.

12

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.