A full-duplex communication bridge that allows the user to change the JDY-40 baud rate via Arduino code (removing the need for USB-to-TTL adapters for setup) and provides a "Heartbeat" signal quality indicator .
This is the most frequently reported issue.
void setup() Serial.begin(9600); // Communication with PC (Serial Monitor) Serial1.begin(9600); // Communication with JDY-40 jdy40 arduino example best
This is the most common point of failure. The JDY-40 is a . Most Arduinos (Uno, Mega, Nano) use 5V logic. Connecting a 5V signal to the JDY-40’s RX pin can permanently damage it.
If you have multiple sets of JDY-40s nearby, change the channel and address: A full-duplex communication bridge that allows the user
This approach gives you a flexible, low‑cost wireless network for up to 999 nodes (IDs 001–999). Keep in mind that all nodes must share the same RF channel; only the ID distinguishes them.
is a . While some users report success with 5V, it is safest to use a 3.3V power source to avoid damaging the chip. Arduino Pin Description 3.3V Power (2.2V - 3.6V) GND Common Ground RX (e.g., D2) Connect to Arduino's SoftwareSerial RX TX (e.g., D3) Connect to Arduino's SoftwareSerial TX GND / High GND for AT commands; High/Floating for data transmission GND GND to keep the module awake Best Arduino Example Code The JDY-40 is a
The JDY-40 is a Bluetooth 4.0 module based on the CSR8510 chipset. It supports a wide range of Bluetooth protocols, including SPP (Serial Port Protocol), HID (Human Interface Device), and more. The module operates at a frequency of 2.4 GHz and has a maximum data transfer rate of 1 Mbps.
The AT+CLSS command changes the fundamental behavior of the GPIO pins from serial communication to various remote-control I/O modes.
Open the Arduino Serial Monitor at with Both NL & CR enabled. Essential AT Commands Send these commands to configure your modules: