# Ultrasonic Sensor HY-SRF05, 5 Pins, 2–450 cm, 5V

- Page: https://sigmanortec.ro/en/ultrasonic-sensor-hy-srf05-5-pins-2450-cm-5v
- Price: 12.64 RON
- Availability: In stock; 1-2 zile
- Reference: 88282 · EAN: 5946704104390
- Category: Mechatronics and IoT > Sensors and Modules > Distance and Presence Sensors
- Specifications: Input Voltage: 5 V; Number of pins: 5; Measuring distance: 2 - 450 cm
- Package (shipping data): 0.015 kg
- Updated: 2026-09-14
- Shop: [Sigmanortec.ro](https://sigmanortec.ro/en/llms.txt)
- Prices: RON, VAT included; prices and stock as of 2026-10-22 01:33 (Europe/Bucharest)

## Description

Ultrasonic module for contactless distance measurement in robots, automation, and Arduino projects, with a range of 2-450 cm and a detection angle of up to 15°. It operates at 5V, uses the TRIG ECHO protocol compatible with HC-SR04, and has 5 pins with OUT for selecting standard mode or single-pin mode. It provides TTL output and good accuracy under ideal conditions.
The HY-SRF05 ultrasonic sensor is a non-contact distance measurement module, functionally compatible with the popular HC-SR04. It uses the same TRIG/ECHO control protocol and also includes an OUT pin for selecting the operating mode. The first three pins (VCC, TRIG, ECHO) are arranged in the same order as on the HC-SR04, while GND is in the last position, after OUT, so when replacing an HC-SR04, the ground pin position must be checked. The module connects directly to Arduino boards (Uno, Nano, Mega, Leonardo) and can also be used with ESP32, STM32, Raspberry Pi Pico, or other platforms. On 3.3V logic boards, the 5V ECHO signal must be adapted through a voltage divider.
Measurement is based on the time of flight of ultrasonic waves. Upon receiving a trigger pulse, the module emits a burst of eight pulses at 40 kHz and waits for the echo reflected by the object. On the ECHO output, it generates a HIGH signal whose duration corresponds to the round-trip time of the wave. Distance is obtained by multiplying this duration by the speed of sound, approximately 340 m/s, and dividing the result by two.
The module’s main features are a measurement range between 2 cm and 450 cm, accuracy of up to 3 mm under ideal conditions, and a detection angle of up to 15 degrees. It is powered by 5 VDC, consumes less than 2 mA at rest, and provides TTL-compatible output. Measurement is not affected by ambient light or the color of the object. The sensor has two separate transducers, a transmitter and a receiver, mounted on a 45 x 21 mm PCB with four mounting holes.
The OUT pin allows selection between two operating modes. Left unconnected, the module operates in standard mode, with separate TRIG and ECHO pins, just like the HC-SR04. Connected to GND, it activates single-pin mode, in which both trigger and echo use the TRIG pin, useful in projects with few free pins. The implementation of single-pin mode may vary depending on the module’s production revision, so standard mode is recommended for general use.
The sensor is suitable for obstacle-avoiding robots, parking assistance systems, non-contact tank level measurement, presence detection, and educational projects. Results are better on hard, flat surfaces oriented perpendicular to the sensor. Soft materials (fabrics, foam) and angled surfaces can reduce the maximum detection distance. The speed of sound varies slightly with temperature, so small measurement deviations may occur at extreme temperatures.
Specifications:
Model: HY-SRF05
Supply voltage: 4.5 – 5.5 VDC (typically 5 VDC)
Idle current: < 2 mA
Operating current: 10 – 40 mA
Operating frequency: 40 kHz
Measurement range: 2 cm – 450 cm
Dead zone: 2 cm
Accuracy: up to 3 mm
Detection angle: max. 15°
Trigger signal: TTL pulse of at least 10 µs
ECHO output signal: TTL (HIGH = VCC, LOW = 0V)
Recommended interval between measurements: at least 60 ms
Operating modes: standard (separate TRIG and ECHO), single-pin
Number of pins: 5 (VCC, TRIG, ECHO, OUT, GND)
Operating temperature: -20 ~ 60°C
Mounting holes: 4 x 2 mm
Dimensions: 45 x 21 mm
Pinout:
Pin
Name
Description
1
VCC
+5 VDC supply
2
TRIG
Trigger input. HIGH pulse of at least 10 us to start the measurement. In single-pin mode, it is also the echo output.
3
ECHO
Echo output. HIGH signal whose duration is proportional to the measured distance. Unused in single-pin mode
4
OUT
Mode selection. Unconnected = standard mode. Connected to GND = single-pin mode.
5
GND
Common ground (GND).
Usage:
Connect the VCC pin to 5V and the GND pin to the development board ground.
For standard mode, leave the OUT pin unconnected, connect TRIG to a digital pin configured as an output, and ECHO to a digital pin configured as an input.
On 3.3V logic boards (ESP32, STM32, Raspberry Pi Pico), connect ECHO through a voltage divider, for example a 1 kOhm resistor in series and a 2 kOhm resistor to GND.
Apply a HIGH pulse of at least 10 µs to the TRIG pin to start the measurement.
Measure the duration of the HIGH signal on the ECHO pin, for example with the pulseIn() function using a timeout of about 30 ms.
Calculate the distance using the formula Distance (cm) = HIGH duration (µs) x 0.034 / 2.
Keep at least 60 ms between two measurements so that residual echoes do not affect the next measurement.
For single-pin mode, connect the OUT pin to GND, use only the TRIG pin for sending the pulse and reading the echo, and leave the ECHO pin unconnected.
In single-pin mode, after sending the pulse, immediately switch the microcontroller pin to input to read the echo. Never connect the TRIG and ECHO pins directly together.
If the module does not respond in single-pin mode, disconnect OUT from GND and use standard mode.
Mount the sensor perpendicular to the target surface, with no obstacles in the detection cone, and avoid operating multiple ultrasonic sensors simultaneously facing the same direction.