HC-05 Bluetooth Module Not Responding to AT Commands
Hey everyone, I'n new here! I'm troubleshooting an issue with my HC-05 Bluetooth module, and I could use some help. I'm trying to enter AT mode to configure settings, but I’m not getting any responses in the Serial Monitor. Here's what I've checked so far:
The HC-05 is in AT mode (blinking once every 2 seconds).
TX/RX are connected properly (Arduino TX → HC-05 RX via voltage divider, HC-05 TX → Arduino RX).
Baud rate is set to 38400 in both the code and Serial Monitor.
Serial Monitor is set to "Both NL & CR".
Tried multiple baud rates (9600, 38400, etc.) with no success.
Tested with and without a PWM-connected servo motor to rule out interference.
Tried disconnecting and reconnecting TX/RX before sending AT commands.
Tried sending a basic "AT" command manually, but no response.
Tested a different Arduino board, no change.
Could this be a faulty module, or am I missing something? Any guidance would be greatly appreciated!
Thanks in advance!
2 Replies
avoid using the Arduinos hardware serial port (Tx/Rx pins 1 & 0)
these pins are used by the Serial Monitor and to upload code
look up
SoftwareSerial and connect the HC-05 to those pins (which you define)usually when I want to configure an HC I use an "FTDI Buddy" type of thing
