Overview
The HC-SR04 Ultrasonic Sensor is a reliable and low-cost module for non-contact distance measurement. It uses the same principles as radar or sonar—emitting a 40kHz sonic burst and calculating the time it takes to return. Because it uses sound rather than light, it is unaffected by sunlight or the color of the object it’s measuring (though soft fabrics can absorb the sound). It’s the “must-have” sensor for every robotics student and DIY enthusiast.
Key Features
Long Range Sensing: Detects objects from as close as 2cm up to a massive 400cm (4 meters).
High Precision: Offers stable readings with an accuracy of up to 3mm.
4-Pin Interface: Uses a simple Trigger (Input) and Echo (Output) system that is easy to code.
Wide Compatibility: Works perfectly with Arduino (via the
NewPinglibrary), ESP32, Raspberry Pi, and STM32.Low Power Consumption: Draws very little current, making it ideal for battery-powered smart cars.
Technical Specifications
| Feature | Specification |
| Operating Voltage | 5V DC |
| Operating Current | 15mA |
| Ultrasonic Frequency | 40kHz |
| Max Range | 4m (400cm) |
| Min Range | 2cm |
| Measuring Angle | 15 Degrees |
| Trigger Input Signal | 10µS TTL pulse |
| Dimensions | 45mm x 20mm x 15mm |

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