Q1：I can't get into AT command mode.
A1：Please check if the serial port monitor of your IDE is set to "NO Line Ending" and set the baud rate to 115200;
Then type "AT" in the input field, press Enter or click the Send button with the mouse. Sometimes it takes several clicks to connect successfully, and "OK" will be returned if the connection succeeds.
Q2：Why can my Bluno only Bluetooth communicate when I turn on the Arduino?
A2：Please use the AT command to modify the Bluetooth baud rate and set the baud rate consistent with the code. Turning on the Arduino serial port monitor defaults to using the baud rate set in the window.
Q3:Why cannot the master and slave devices be configured on the two Bluetooth boards?
A3:After setting the master-slave mode, power off the two boards and then power on again, and bring the two boards close to each other. The link light will light up within a few minutes, indicating that the Bluetooth connection is successful.
If you have other questions, just feel free to post them in our forum for consultation. We will reply them as soon as possible and improve the product FAQ gradually.