In this lesson, a simple yet interesting experiment will be conducted, using LEDs to create flowing LED lights. As the name implies, these flowing lights are made up of six LEDs in a row which successively light up and dim one after another like flowing water.


- 1 Uno board.
- 1 Breadboard.
- Jumper wires.
- 6 LEDs.
- 6 Resistor (220Ω).
- 1 USB cable.


The principle of this experiment is simply to turn six LEDs successively, each LED will light and dim in a certain pattern with respect to the other LEDs, during this lesson, new concepts will be implemented in the code part.

You should be aware that LEDs have many types such RGB LEDs; we are dealing in this experiment with the normal traditional LED, and nowadays, LEDs are included in many lighting industries, the industrial community is depending more and more on LEDs.

Experimental Procedures

Step 1: Connect circuit as shown in Fig1, the corresponding schematic diagram is in Fig2. (the schematic is generated by EAGLE).
Step 2: Program the Arduino (download program from documents).
Step 3: Compile the program.
Step 4: Burn the program into the Uno board.

Here you should see the six LEDs lighting up one by one starting from the first to the last, and then dim one by one starting from last. After that, the LEDs will light up one by one from the last one to the first, and then dim one by one from first to last. This process will repeat indefinitely.

Experiment Summary

This simple experiment helps to increase proficiency in using LEDs, it also allows you to use the output mode in the Arduino uno, Furthermore, you can modify the provided program to create all kinds of fantastic patterns.

circuit connection

Fig1: LEDs connection

eagle schematic

Fig2: schematic for LEDs connection


1-Arduino progrme (code)
2-Eagle file