The SG90 servo motor sweeps the attached HC-SR04 ultrasonic sensor across a range of angles. At each step, the sensor emits high-frequency sound waves and measures the echo return time to calculate distance. The Arduino Nano reads this distance data alongside the corresponding servo angle and transmits it over serial to a Processing application, which renders a 2D radar display.
Why Build This
Gain hands-on experience with ultrasonic distance measurement
Learn how to combine sensor inputs with motorized sweeping
Create a visual radar map interface on your computer
Understand the foundational principles used in robotics and automation
Real-World Application
Ultrasonic radar and scanning principles are widely applied in autonomous robotics for obstacle detection, security and surveillance monitoring systems, and industrial automation profiling.
Skills You'll Learn
Interfacing ultrasonic sensors with microcontrollers
Controlling servo motor angles programmatically
Serial communication between Arduino and computer software
Real-time data visualization using Processing
Safety Precautions
Always double-check your circuit wiring and power connections before plugging the USB cable into your computer to prevent short circuits. Ensure all sensor and motor pins are properly matched to their respective 5V, GND, and digital pins. Handle the servo and sensor components gently to avoid bending delicate connector pins.
Technology Tags
ARDUINO NANO
HC-SR04
SG90 SERVO
ULTRASONIC SENSOR
PROCESSING IDE
SONAR
BREADBOARD
Frequently Asked Questions
You need the Arduino IDE to upload the firmware to the Arduino Nano and the Processing application to run the graphical radar interface on your computer.
Yes, other Arduino boards like the Arduino Uno or compatible microcontrollers with sufficient digital pins and serial communication support can be used with minor pin adjustments.
The HC-SR04 typically has a reliable measuring range from about 2 centimeters up to 4 meters depending on target reflectivity and environmental conditions.
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