Arduino project · Displays and counters · Easy
Level Meter with a Knob (16 LEDs)
Turn the knob and the row of LEDs fills up like a volume meter.
What you will learn
- How a bar graph shows a value
- How map scales 0 to 100 into 0 to 16
- How a level meter works in an amplifier
How it works
The Map step converts the knob to a number from 0 to 16 and the bar mode lights that many LEDs.
Try this next
- Reverse the bar.
- Change the colour of the last 3 LEDs to red.
- Use a light sensor instead.
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 16-light level meter
Turn the knob and more lights switch on, like a stereo level meter.
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 = the knob
- 16-LED driver = the bar