Bluetooth AT Commands

CHANGE INTERNAL SETTING OF BLUETOOTH MODULE LIKE PASSWORD, NAME ETC

To change internal settings we need to set Bluetooth in AT command mode, follow the steps below to set Bluetooth (BT) in AT command mode to use Bluetooth AT commands.

What is AT Command in Bluetooth? It means Attention Command, make attention to the controller, now we are using you not as simple data but for commands.

STEPS TO SET BLUETOOTH IN AT COMMAND MODE

Caution: If the module is connected to any other Bluetooth device, it starts to communicate with that device and fails to work in AT command mode.

1. To enable AT command mode, take arduino, BT – HC05, 5 male to female connectors
2. Upload a blank program to arduino

   void setup() {
   }
   void loop() {
   }
   

3. Then, connect pins as follows

After all connection made, pick out ground pin of BT from arduino

4. Press the button switch (of Bluetooth module) for a second and connect the ground wire (which was picked out in the previous step) to the arduino. Then you will observe BT module led blinks once for every 2 seconds rather than continuous blinking. If you find continuously blinking for every half of a second it means you didn’t enter “AT command mode”, don’t worry try again the same step.
5. As you entered in AT command mode, opens Serial monitor in Arduino IDE and sets the baud rate of 38400 in the serial monitor
   

   

    

6. Then type AT and send it, you will receive OK on the serial monitor, which means you successfully entered in AT command mode.

INPUT

OUTPUT

SOME BLUETOOTH AT COMMANDS

1) TO SEE EXISTING NAME:

After entering in AT command mode:

To see the existing name of the Bluetooth device type “AT+NAME” and send it will return the “name” of the Bluetooth device here is “HC-05” shown in fig.

INPUT

OUTPUT

2) TO CHANGE NAME:

To change the existing name of the Bluetooth device type “AT+NAME=name you want” here SHOOLIN LABS and send it will return back OK that your command accepted successfully shown in fig.

INPUT

OUTPUT

Re-check the updated name of the device by command AT+NAME. Yes it is updated

INPUT

OUTPUT

3) TO SEE EXISTING PASSWORD:

To see the existing password of the Bluetooth device type “AT+PSWD” and send it will return back “password” of the Bluetooth device here is “1234” shown in fig.

INPUT

OUTPUT

4) TO CHANGE PASSWORD

To change the existing passwords of the Bluetooth device type [AT+PSWD=”password you want”] in double course, here PASSWORD and send it will return back OK that your command accepted successfully shown in fig.

INPUT

OUTPUT

Re-check updated password of device by command AT+PSWD. Yes it is updated

INPUT

OUTPUT

FEW MORE BLUETOOTH AT COMMANDS

1) TEST

2) Reset

3) Get the soft version

4) Restore default status

Default status:

• Device type: 0
• Module work mode: Slave Mode
• Serial parameter: Baud rate: 38400 bits/s; Stop bit: 1 bit; Parity bit: None.
• Passkey: “1234”
• Device name: “HC-05”

For more commands we will update a PDF file soon

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