If you want to get into home automation but wary about exposing your system on the internet, then this board may be just right for you. This 4-channel relay board allows you to turn ON and OFF various gadgets around your home remotely, but instead of WiFi, it uses Bluetooth wireless as the medium. The catch is you won't have access to the system outside your home, but then so are the malicious hackers.
This Bluetooth Relay module has 4 relay channels that you can use to control up to four home appliances and gadgets. With the use of Bluetooth SPP apps, you can easily build a basic wireless remote control system using your phone as the remote console, without the need for a host controller and programming.
4 10 Amps NC/NO channels
Supply Voltage: 12VDC, >0.5A
4-byte Hex Command Stream format: A0 0n 0x NN
Byte 0: A0 = command header
Byte 1: 0n - channel number ch1=01 ch2=02 and so on
Byte 3: 0x - 01 = ON 00=OFF
Byte 4: NN =Sum of Byte 0 to Byte3
Tried and tested on this free Android App: BlueSPP - Apps on Google Play
BlueSPP Quick Instructions
1) Set BlueSPP Preference as Send HEX Data = ON, Receive HEX Data = OFF
2) Click the "KEYBOARD" tab and program the button to send data stream as described above. Give each button a name you can easily recognize.
Example: Program in Button Editor window so that pressing a button will turn ON channel 1 (Patio light ON)
Note: Make sure all HEX selection is ON in the editor window
Button Text = "Patio Light ON"
Status Press= A0 01 01 A2
Click OK to finish a button setup. Setup more buttons if you so desire.
3) Click CONNECT (located in the upper right corner of your app's window).
4) If you have not previously paired your Bluetooth Relay with your apps, click search to find your Bluetooth Relay Device (the default name may be " JY-30" or "SPP"), and then click it to pair and connect with the apps. If you are asked for a password, enter "1234".
5) Your Bluetooth Relay device is now ready to go.
You can replace the password (and you should) but this requires additional setup and a procedure too long to discuss here.