Match the baud rates on both modules and ensure SoftwareSerial matches jdy40.begin() .
: Chip select pin. Pull LOW to enable the module. Pull HIGH to sleep. Configuring JDY-40 with AT Commands
If you want maximum reliability, use a voltage divider on the Arduino TX → JDY-40 RX line: jdy40 arduino example best
| Command | Function | Example Response | | :--- | :--- | :--- | | AT | Test connection | OK | | AT+VERSION | Query firmware version | Version=... | | AT+NAMEyourname | Change BT Name | OK (Sets name to "yourname") | | AT+BAUD4 | Set Baud Rate | OK (4 = 9600, 5 = 19200, etc.) |
Using 5V on VCC will fry the JDY-40. Don’t do it. Match the baud rates on both modules and
Sets the wireless network ID. Send AT+DADDR0001 →right arrow Sets the device address.
For a deeper dive into the AT command sequence and advanced configuration, the detailed AT command set analysis is an excellent resource. If you'd like to explore more, I can provide: A for connecting the JDY-40 to a 5V Arduino Nano . Pull HIGH to sleep
Here is a quick reference of the most common AT commands to get you started:
. Because it uses 2.4GHz RF technology (similar to an NRF24L01 but with a simplified serial interface), it broadcasts to all other JDY-40 modules on its channel automatically. The "best" example of its power is a Hub-and-Spoke sensor network
Use the same wiring as in Example 1. However, for the transmitter Arduino (the one with the sensor), you might want to use a different pair of pins for the JDY-40 so you can still use the built-in serial port for debugging. This is where SoftwareSerial becomes very useful.
What are you looking to send? (e.g., simple text strings, sensor values, motor commands)