Arduino 4W COB LED Tutorial

High Power LEDs are very popular and low cost nowadays so I thought it would be a good idea to learn how control them with Arduino. So, I built a simple project that simply turns on a 4W Cob LED when the button is pressed. When the button is pressed again, the LED turns off. The LED is powered by 12V battery and it is controlled by the Arduino using a MOSFET. But let’s see how to build it.

The parts needed in order to build this project are these:

• An Arduino
• A 4W Cob LED, or similar
• A MOSFET module
• A boost converter
• A constant current driver
• A pushbutton
• 12V battery or power supply

The cost of the project if you exclude the battery is about 10 Euros.


1. 4W COB LED:

2. Mosfet module:

3. Boost Converter:

4. Constant Current:

5. Cheap Arduino Uno:

6. Push Buttons:

7. Small Breadboard:

8. Siren:

9. Multimeter:

10. Wires:

Before we start, I would like to warn you, that you have to very careful when you are working with voltages over 12V. Misuse of tools or materials can cause injury and mismanagement of electricity can cause electric shock or explosion, I do not take responsibility for the consequences of making the projects shown in the videos from this channel, proceed at your own risk.

This LED works best at around 15V. So in order to achieve that we have to rise the voltage of the 12V battery to 15V. For that we are going to use this boost converter module. With this potentiometer we can change the output voltage of it. I set it to 15V and we can move on.
Next we have to limit the amount of current that runs through the LED in order to avoid overheating and destruction of it. In order to achieve that we are going to use this constant current and voltage driver. This module has three potentiometers. The first one sets the voltage limit. We set it to 15V using a Multimeter.

Next we change the third potentiometer in order to set the current limit to 250mA. Be careful to set up your Multimeter correctly in order to avoid destruction of it. That’s it, if we now connect the LED to the battery via these two modules it will light up very brightly.

But if we want to control the LED with an Arduino we are going to need the MOSFET module. Think of it, as a digital switch intended for high voltages and currents. This MOSFET module can handle up to 24V and 5A so it is well suited for this project. We connect the output of the constant current module to input of the module. Then we connect the LED to the output of the MOSFET module. Now all we have to do is to connect the MOSFET module with the Arduino Uno board in order to control it. The connection with Arduino is very easy. We connect Ground to Arduino Ground, Vcc to Arduino 5V and lastly we connect the signal pin to digital pin 10 of the Arduino Uno. Next we connect a pushbutton to Arduino. One leg of the button goes to GND and the other one goes to digital pin 2. That’s it. Now we are able to control the LED with Arduino. Be careful, this particular LED gets hot quickly, so we need a heatsink if we want to have it on for a long period of time. But we will get to that in a future video.









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