Arduino project · LEDs and lights · Easy
Knob Level Ring
Turn the knob to fill the ring, like a volume indicator.
What you will learn
- How to turn a measurement into a bar graph
- How map() converts 0 to 100 percent into 0 to 8 pixels
- How one value drives many LEDs
How it works
The potentiometer value goes into a map step that gives a number from 0 to 8. That many pixels are lit, each in its own colour. Turning the knob up lights more pixels.
Try this next
- Use a light sensor instead of the knob.
- Add a buzzer that sounds at full ring.
- Show the temperature on the ring.
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 glowing ring of lights
The ring lights as many pixels as your program asks for, from green to red.
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.
- NeoPixel ring = the glowing ring