Aj Sr04m Datasheet ^new^ -

Actual distance = Measured distance * (343.0 / sqrt(331.3 * (1 + T_celsius/273.15))) | Parameter | Conditions | Value | |-----------|------------|-------| | Supply voltage | Absolute max | 5.5V | | Supply voltage | Operating | 4.5V – 5.5V | | Logic input low | Trig, EN | < 0.8V | | Logic input high | Trig, EN | > 2.0V (3.3V compatible) | | Echo output low | IOL = 2mA | < 0.4V | | Echo output high | IOH = 2mA | > 4.0V (5V logic) | | Output impedance | - | 100 Ω |

delay(60);

AJ-SR04M is the best all-rounder for outdoor/wet applications needing short-range detection (2 cm blind zone). JSN-SR04T has longer range but larger blind zone (20 cm). HC-SR04 is indoor only. 10. Application Circuit & Code Examples 10.1 Arduino (Standard) #define TRIG 9 #define ECHO 10 void setup() Serial.begin(9600); pinMode(TRIG, OUTPUT); pinMode(ECHO, INPUT); aj sr04m datasheet

For better than 1% accuracy, read a separate temp sensor (e.g., DS18B20) and compute: Actual distance = Measured distance * (343

long duration = pulseIn(ECHO, HIGH, 30000); // timeout 30ms (≈5m) if (duration == 0) Serial.println("Out of range"); else float distance = duration / 58.3; Serial.print("Distance: "); Serial.print(distance); Serial.println(" cm"); Unlike the standard HC-SR04, this module is enclosed

1. Overview & Key Differentiators The AJ-SR04M is an improved, industrial-grade variant of the popular HC-SR04. Unlike the standard HC-SR04, this module is enclosed in a waterproof, IP67-rated housing , making it suitable for outdoor, dusty, or humid environments (e.g., tank level sensing, outdoor robotics, car reverse sensors).