Arduino project · LEDs and lights · Medium
LED Chaser with Speed Knob
Three LEDs run in a row. The knob is on the board, ready for you to make the speed adjustable.
What you will learn
- How a chaser works
- Why a fixed delay gives a fixed speed
- How to plan a speed control (the next step for you)
How it works
The simulator steps use fixed times, so the speed here is fixed at 300 ms per light. In real Arduino code you would read the knob with analogRead() and use it as the delay time. The challenge below shows how.
Try this next
- In the code, replace delay(300) with delay(map(analogRead(A0), 0, 1023, 50, 600)).
- Add a fourth LED.
- Make the light run back and forth.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
A sign with a speed knob
Turn the knob. The running lights speed up and slow down.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- Potentiometer = speed knob
- LEDs = the bulbs