Anonymous
Mar 19, 2026
Rating: 5/5
Reliable and cheap
Bought five of these for a parking assist system I'm building. All five arrived working perfectly. The response time is fast enough for real-time applications.
Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | HC-SR04 |
| Operating Voltage | 5V DC |
| Static Current | < 2mA |
| Measuring Angle | 15 degrees |
| Measuring Range | 2cm to 400cm |
| Resolution | 0.3cm |
| Trigger Input Signal | 10µS TTL pulse |
| Dimensions | 45mm x 20mm x 15mm |
| Interface Type | 4-Pin Header (VCC, Trig, Echo, GND) |
| Compatibility | Arduino, Raspberry Pi, STM32 |
Anonymous
Mar 19, 2026
Rating: 5/5
Reliable and cheap
Bought five of these for a parking assist system I'm building. All five arrived working perfectly. The response time is fast enough for real-time applications.
Anonymous
Mar 08, 2026
Rating: 5/5
Perfect for Arduino robotics projects
This sensor works flawlessly with my Arduino Uno. The distance readings are consistent and accurate within the specified range. Great value for the price.
Anonymous
Mar 05, 2026
Rating: 4/5
Great for education
We use these in our high school robotics club. They are durable enough to handle student mistakes and provide clear data for learning logic and physics.
Anonymous
Mar 04, 2026
Rating: 5/5
Standard component, works as advertised
If you need a basic ultrasonic sensor, this is the industry standard. Documentation is everywhere online, making it very beginner-friendly.
Anonymous
Mar 03, 2026
Rating: 4/5
Good accuracy, easy to wire
Used this for a university project. Wiring was straightforward using standard libraries. It struggles slightly with very soft surfaces that absorb sound, but that is expected physics.
Anonymous
Mar 02, 2026
Rating: 5/5
Excellent range detection
Tested up to 3 meters and it held up well. The 15-degree cone is narrow enough to avoid too much interference from nearby objects in tight spaces.
Q: What is the minimum object size this can detect?
A: The sensor can generally detect objects as small as a few centimeters in diameter, provided they are reflective enough to bounce the ultrasonic wave back to the receiver. Small wires may be difficult to detect consistently.
Q: How do I handle multiple sensors on one board without interference?
A: To use multiple sensors, trigger them sequentially rather than simultaneously. Add a small delay (e.g., 60ms) between triggering each sensor to allow the sound waves from the previous measurement to dissipate.
Q: Can this sensor be powered directly by a 3.3V Raspberry Pi GPIO pin?
A: While the module operates at 5V, many users successfully run it on 3.3V logic levels. However, for stable performance, we recommend using a 5V power source and a voltage divider or level shifter for the Echo pin to protect the Pi.
Q: Does this come with jumper wires included?
A: No, the package includes only the ultrasonic module itself. Jumper wires are sold separately, but any standard male-to-male jumper wires will work.
Q: Is this waterproof for outdoor use?
A: No, the HC-SR04 is not waterproof. The exposed transducers and circuit board can be damaged by moisture. For outdoor use, you must house it in a waterproof enclosure with a sound-permeable front.