How to use an Arduino RGB LED

This guide provides you some information about Arduino RGB LEDs and how you can use or control them with Ozeki 10. You will learn about the basic concept of RGB LEDs in the first part of the document, then, by following the step by step guide, you will be able to see that how you can control these RGB LEDs from your computer using Ozeki 10. So, let's start right now.

What is RGB?

Stands for "Red Green Blue." RGB refers to three hues of light that can be mixed together to create different colors. Combining red, green, and blue light is the standard method of producing color images on screens, such as TVs, computer monitors, and smartphone screens.

What is an RGB LED?

There are actually two types of RGB led’s; the common cathode one and the common anode one. In the common cathode RGB led, the cathode of all the led’s is common and we give PWM signals to the anode of led’s while in the common anode RGB led, the anode of all the led’s is common and we give PWM signals to the cathode of led’s.

How does an RGB LED work?

The RGB LED can emit different colors by mixing the 3 basic colors red, green and blue. So it actually consists of 3 separate LEDs red, green and blue packed in a single case. That’s why it has 4 leads, one lead for each of the 3 colors and one common cathode or anode depending on the RGB LED type. The cathode will be connected to the ground and the 3 anodes will be connected through 220 Ohms resistors to 3 digital pins on the Arduino Board that can provide PWM signal. We will use PWM for simulating analog output which will provide different voltage levels to the LEDs so we can get the desired colors.

Arduino RGB LED wiring diagram

wiring diagram of arduino rgb led
Figure 1 - Wiring diagram of Arduino RGB LED

How to use an Arduino RGB LED in Ozeki

RGB LED controller connection easily controls the brightness and color of your RGB LED. Commands can be routed to your LED controller from any connection of your Ozeki 10. You can mix any color by using the correct scale of the 3 basic colors. Each color is scaled from 0 to 255. You can change brightness while keeping the color at the same time. To use the RGB LED in Ozeki, you first need to download Ozeki Robot Developer. Ozeki Robot Developer will install the Arduino libraries needed to use this sensor efficiently.

Download Ozeki Robot Developer

Download Ozeki Robot Developer

After Ozeki Robot developer is installed, you need to upload the RGB LED control code to your Arduino. You can find the code and download instructions on the following pages. The upload process includes two steps: first you need to format the EEPROM of the arduino, then you need to upload the control code. The procedure is very simple, it only takes a few seconds.

Upload the RGB LED code to Arduino Uno
Upload the RGB LED code to Arduino Mega 2560
Upload the RGB LED code to Arduino Nano
Upload the RGB LED code to Raspberry Pi

The arduino sensors and Ozeki will communicate over the USB port using the Ozeki RGB LED protocol. This protocol makes it possible for you to use the sensor directly on your PC. You will be able to control this sensor through the web based user interface or you will be able to communicate with it using Ozeki Chat. You can read more about chat control on the following page.

How to communicate with the RGB LED using chat

It is important to understand chat control, because when you build a robot, the way you wish to control this sensor is by sending and receiving messages. If you open the Ozeki Robot Developer app, you will see, who you can write a C#.Net program to work with this sensor.

Connection steps

  1. Use the wiring diagram to connect the RGB LED to your Arduino
  2. Plug the Arduino board into your PC
  3. Check the COM ports in Windows device list
  4. Open the Arduino application on your computer
  5. Upload the example code to the Arduino
  6. Open Ozeki 10 GUI in your browser
  7. Choose the connection of the RGB LED
  8. Test the RGB LED by setting a colour in Ozeki 10

System overview

The system we suggest consists of an RGB LED, that is wired to the analog port of your Arduino. The Arduino will be responsible for reading data from this device in real-time. The brain of the system will be running on a PC (Figure 2). On the PC, Ozeki 10 will be able to manage the communication. You can easily run Ozeki 10 using a webbrowser

system config of led
Figure 2 - System configuration of RGB LED connecting to PC using Arduino

Prerequisites

  • RGB LED
  • 2x100Ω and 1x220Ω resistor
  • Ozeki 10 installed on your computer
  • Programmable board (Arduino Mega/Nano/Uno or Raspberry Pi)
  • USB cable is needed between Arduino Mega/Nano/Uno and your computer

Step 1 - Wire the RGB LED to your Arduino

You can see how to wire the RGB LED to any of the following boards:

After wiring, please plug the board to your computer!

Step 2 - Upload code to the microcontroller

(Here is the code to upload)

Step 3 - Start Ozeki 10 to try the RGB LED

Step 4 - Configure your RGB LED in Ozeki 10

In order to configure your RGB LED (attached to your Arduino) in Ozeki 10, that is installed on your computer, you need to open the graphical user interface (GUI) of Ozeki 10. You can open the GUI by entering the URL of the computer into your webbrowser. For example, if our PC has an IP address of 192.168.1.5, we would enter http://192.168.1.5:9513 into our webbrowser.

Step 5 - Understand the RGB LED protocol

The RGB LED Controller can communicate with Ozeki through the following protocol.

References:
https://howtomechatronics.com
https://create.arduino.cc
https://techterms.com

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