Arduino project · Distance and parking · Medium
Toll Barrier with Distance Display
The barrier lifts when a vehicle is closer than 25 cm, and the LCD shows how far the vehicle is.
What you will learn
- How an ultrasonic sensor opens a barrier
- How to show a live number on an LCD
- How automatic toll plazas detect cars
How it works
The distance is checked every 200 ms. Under 25 cm the servo goes to 90 degrees, otherwise it goes back to 0 degrees.
Try this next
- Show OPEN or CLOSED on the second line.
- Beep when the barrier lifts.
- Count the vehicles.
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 toll barrier
Move the distance slider. When a vehicle comes close, the toll barrier lifts.
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.
- Distance sensor = the vehicle
- Servo = the barrier arm