Small Bluetooth Device

Hi, I'm new to this site and forum, and I'm not too brilliant with electronics, but I can learn :grin:
I have some knowledge on programming though.

What I wanted to know is if it's possible to create a small bluetooth device that would be plugged into an AC power outlet, and just transmit a bluetooth signal, I don't require any device to connect to it.
So, in my case, I would want my cell phone to "see" the bluetooth signal but I wouldn't want the cell phone to connect to it.
I would also like to be able to connect the bluetooth device to a PC to configure the name identifier, i.e. the name that would appear under bluetooth devices on the cell phone.

I would just like to know if it's possible; I have checked on the internet to find something of the sort but haven't had much luck. And if it's possible, could someone point me in the right direction, e.g. what product I should use and where to start.


if your cellphone is BT2.0 , at least you will need :?AC_DC module, microcontroller such as Arduno, BT 2.0 module and an simple app to display information on your phone. suggest the BT Bee module. , if your phone uses BT4.0, a BT4.0 module would work

Hello and welcome :slight_smile:

With a cheap BT module such as the HC-07 (search on ebay), you just need to power it with 5VDC and it will be detectable by your phone.

To configure it, the easiest way is to use a USB to Serial adapter: search ebay for "PL2303". It's a little tricky to install it's driver if you use Windows 8 64bits, so PM me if you have problems with it.


You connect the HC-07 to it ( RX to TX, TX to RX, VCC to 5V, GND to GND ) then plug into your computer, then you open the Arduino IDE's Serial Monitor (or any other Serial terminal) on the corresponding Port and at 9600 bauds, and send AT commands.

Default password is 1234, and here is details of the available AT commands for the HC-07:

some chinese vendor:
1, test communications
Send: AT
Return: OK

2, change the Bluetooth serial communication baud rate

Send: AT + BAUD1
Returns: OK1200

Send: AT + BAUD2
Returns: OK2400
1 --------- 1200
2 --------- 2400
3 --------- 4800
4 --------- 9600
5 --------- 19200
6 --------- 38400
7 --------- 57600
8 --------- 115200
9 --------- 230400
A --------- 460800
B --------- 921600
C --------- 1382400

Not recommended for more than 115200 baud rate, signal interference make the system unstable.
Set with more than 115,200 machine is unavailable, use microcontroller programming at higher than 115 200 in order to use this baud rate and re-issued AT command set low baud rate
AT command to set the baud rate, the next power to use without re-set, you can power down to save baud rate.

3, change the Bluetooth name

Send: AT + NAMEname
Returns: the OKname
Parameter name: To set the current name, the Bluetooth name to be searched. 20 characters or less.
Example: Sending AT + NAMEbill_gates
Return OKname
To changed bill_gates Then the Bluetooth name
Parameters can be powered down to save, simply modify the time. PDA-side refresh you can see the Bluetooth name changed.

4, change the Bluetooth passkey

Send: AT + PINxxxx
Returns: the OKsetpin
Parameter xxxx: To set a passcode, 4 bytes, this command can be used from the machine or the host. The slave adapter or mobile phone pops up to enter the passkey window, then manually enter this parameter can be connected to the slave. Host with the master Bluetooth module with digital cameras, digital cameras from the machine, find the password of the camera pair, and then set up the White Bluetooth module, the master Bluetooth module can automatically connect the camera.
Example: Sending AT + PIN8888
Return OKsetpin
At this time the Bluetooth pairing password to 8888, the module at the factory default passkey is 1234.
Parameters can be powered down to save, simply modify the time.

Note that you can also use your Arduino to configure it, but it's more work for you, I don't recommend it.