The HC-SR04 Ultrasonic Sensor is the most-used distance sensor in the Arduino world, and for good reason: it accurately measures how far away an object is by bouncing ultrasonic sound off it. If you are building an obstacle-avoiding robot, a smart parking system or an ultrasonic radar, this is the module you want.
Key Features
- Non-contact distance measurement from 2 cm to 400 cm
- Accuracy up to ~3 mm
- Simple 4-pin interface (VCC, Trig, Echo, GND)
- Stable readings, low power consumption
- Tons of Arduino libraries and example code available
Specifications
| Working voltage | 5V DC |
| Range | 2 cm – 400 cm |
| Resolution | ~0.3 cm |
| Measuring angle | ~15° |
| Trigger pulse | 10 µs TTL |
| Frequency | 40 kHz |
Popular Project Ideas
- Obstacle-avoiding / self-driving robot car
- Ultrasonic radar with servo + Processing
- Smart car parking / reverse sensor
- Water-tank level indicator
- Blind-stick and assistive projects
Buy it from Arduino Corner — Pakistan’s dedicated Arduino & electronics store in Rawalpindi. Genuine parts, tested before dispatch, COD across Pakistan, and friendly support for your student and university projects.
