After setting AT+RFNETID , the modules automatically pair. No need for AT+LINK or address targeting. This is transparent broadcasting — anything one sends, all receive. Best Use Cases (With Example Sketches) 1. Wireless Sensor Node (Low Power) Send temperature every 60 seconds, then sleep the Arduino + JDY-40.
void loop() // ----- TRANSMIT BEST PRACTICE ----- static unsigned long lastSend = 0; if (millis() - lastSend > 2000) lastSend = millis();
// Best practice: Send structured, short packets // Never send Strings larger than the buffer (max 64 bytes per packet) jdy40.print("TEMP:"); jdy40.print(23.5); jdy40.print(";BAT:"); jdy40.println(4.12);
#include <SoftwareSerial.h> // Define RX (JDY-40 TX) and TX (JDY-40 RX) pins SoftwareSerial jdy40(2, 3); // RX = pin 2, TX = pin 3