To change settings like the Channel (to avoid interference), Address, or Baud Rate, you must enter AT command mode. Setting Up for AT Mode Connect the pin to GND . Power on the module. Use the following code to send commands. AT Command Example Code
The JDY-40 module provides a beginner-friendly way to add wireless serial communication to Arduino projects. With auto-pairing and transparent UART interface, a functional link can be implemented in less than 10 lines of code. Its limitations (half-duplex, moderate range) are acceptable for many educational and hobbyist applications.
#include <SoftwareSerial.h>
// Start JDY Serial at Default Factory Baud jdySerial.begin(JDY_DEFAULT_BAUD);
Pull for normal operation; pull HIGH to enter low-power sleep mode. Wiring Diagram: Arduino to JDY-40 jdy40 arduino example best
#define DHTPIN 2 #define DHTTYPE DHT11 DHT dht(DHTPIN, DHTTYPE);
Note: For reliable operation, it is recommended to use to communicate with the JDY-40 to leave the hardware serial (pins 0 & 1) open for USB debugging. 3. The Best JDY-40 Arduino Example: Wireless Serial Bridge To change settings like the Channel (to avoid
: Receive Pin (Connects to Arduino TX via a voltage divider)