HC-SR04 User Guide

Arduino connects ultrasonic sensor for distance measurement

Ultrasonic sensors are suitable for static distance measurement of large flat surfaces. The range of ordinary ultrasonic sensors is about 2cm-450cm, and the resolution is 3mm (the test environment is not so good, and the personal measurement is relatively stable. The distance is about 10cm-2m. If this distance is exceeded, accidental inaccuracies often occur. Of course not Eliminate technical issues.)

The test object is the SRF-04 ultrasonic sensor, which has four pins: 5v power supply pin (Vcc), trigger control terminal (Trig), receiving terminal (Echo), and ground terminal (GND)

How to use the module:

Using this module, occupies two IO ports of the single-chip microcomputer, and one IO port is used as the trigger terminal. One IO port is used as the echo PWM signal capture pin. When writing the program, firstly set the level of 8 40K cycles at the TXD pin, and the program is processed into a PWM signal and output from the RXD pin. Once an echo signal is detected, the echo signal is output for our convenience. When we use it, we only need to read the low level time (T). The echo signal is a distance object proportional to the pulse width. The distance can be calculated from the time interval between the transmitted signal and the received echo signal. Formula: uS/58=cm or uS/148=inch. The formula L=340T/2 can also be propagated in the air by sound waves. You can find L (measured distance). If no reverberation signal is detected, the module’s reverberation signal pin will output a level of about 140uS to prevent the transmitted signal from affecting the reverberation signal.

The working principle of the module:

IO trigger ranging to at least 10us high signal;

module automatically sends eight 40kHz square wave, automatically detect whether a signal return;

a signal to return to a high IO output, high duration of the ultrasonic time from launch to return.

Test distance = (time high * speed of sound (340M / S)) / 2;

Circuit connection method:

Arduino program example:

const int TrigPin = 2;
const int EchoPin = 3;
float cm;
void setup()
{
Serial.begin(9600);
pinMode(TrigPin, OUTPUT);
pinMode(EchoPin, INPUT);
}
void loop()
{
digitalWrite(TrigPin, LOW); //Send a short time pulse to TrigPin
delayMicroseconds(2);
digitalWrite(TrigPin, HIGH);
delayMicroseconds(10);
digitalWrite(TrigPin, LOW);

cm = pulseIn(EchoPin, HIGH) / 58.0; //Convert the echo time to cm
cm = (int(cm * 100.0)) / 100.0; //Keep two decimal places
Serial.print(cm);
Serial.print("cm");
Serial.println();
delay(1000);
}

Download: http://pan.baidu.com/s/1zKSbC

To：

Dear Customers, There may be a lag of several hours before we could process your order, depending on the time difference between your location and ours. Sincerely hoping your understanding!

Email(support)

services01@spotpear.com

TAG： RM520N GL 5G/4G/3G M.2 Moudle IoT EMBB For LTE-A/NSA/SA And GNSS For DFOTA /VoLTE For Quectel Raspberry Pi IR Ther Raspberry Pi 5 PCIe FFC Connector to Standard PCIe x1 Slot (C) Expansion Board LCD1602 I2C Module PWM Adjustable backlight 3.3V/5V For Arduino/ Raspberry Pi/ Pico/ Jetson Nano/ ESP32 2.66inch e-Paper e-link Module 360x184 4-Color Red Yellow Black White For Arduino Raspberry Pi STM32 Jetson Tutorial Information Wiki Program Code User Guide SpotPear Raspberry Pi Pico 2 W RP2350 Pico2W ARM Cortex-M33 And RISC-V Hazard3 Wi-Fi4 Bluetooth5.2 CYW43439 4 inch e Paper HAT+ E Ink Spectra E6 Full-Color 600x400 Screen Display For Arduino /Raspberry Pi /Jetson Nano /STM32 IMX477 IR CUT Camera (A) 12.3MP For Jetson Nano/Orin And Raspberry Pi ESP32-S3 DeepSeek AI Box Robot Development Board N16R8 Toy Doll Option 0.71 inch Electronic Eyes Luckfox Pico RJ45 D-Robotics RDK X3 Module Core MD Module Horizon Sunrise Pi ARM Cortex-A53 5Tops Size Compatible With Raspberry Pi CM4 Size Spotpear Raspberry Pi Pico ST7789 Raspberry Pi 5/4B not boot To update BootLoader EEPROM Tutorial Raspberry Pi 1.3inch LCD Industrial-grade isolated 2-way RS485 hub repeater One RS485 TO Two RS485 ESP32 C6 Development board 1.9 inch LCD display 1.9inch Screen 172×320 With SD slot RGB LED QMI8658 6-Axis-Sensor ST7789 CST816 Raspberry Pi 8.8 inch DSI MIPI Display LCD Capacitive TouchScreen 480x1920 Computer USB Monitor Screen Tutorial

Ultrasonic Wave Detector Ranging Module PICAXE Microcontroller Sensor HC SR0 for Arduino/51/STM32

TAG： Raspberry Pi 5 PD Trigger USB CAN Analyzer Electronic EYE 0.71inch Round Double LCD Display Screen Arduino Raspberry Pi ESP32 Pico STM32 64MP-AF-Camera-Board Raspberry Pi Pico 2 RP2350 CAN Onboard XL2515 CAN Controller RP2350A RDK X5 Binocular Depth Camera Module D-Robotics SC132GS Dual 1.3MP Global Shutter Allwinner ESP32-S3 AI RLCD Total Reflection Screen 4.2 inch Development Board Deepseek Industrial Modbus RS485 RTU 8-ch Magnetic Latching Relay Module (C) With Digital Input UART TTL To RS485 Pi5 3.5 inch LCD Luckfox Pico WebBee RV1103 Ethernet PHY SLC NAND FLASH Case Raspberry Pi 0.96inch LCD ESP32-S3 AI Camera Development Board Dual Microphone with Display Port USB-CAN-B Raspberry Pi 8 inch DSI LCD Display MIPI 800×480 Capacitive TouchScreen SpeedyBee F405 Mini FC F4 Flight Controller FPV DJI Drone Raspberry Pi CM5 IO BASE B Mini Board a Base Development Platform Compute Module 5 IO Board with EEPROM And Encryption chip Modbus RTU CAN