Sending Data to Arduino via Bluetooth Module

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HC-05 module Information

• This module works at 3.3V. We can connect to 5V supply voltage because the module has 5 to 3.3 V regulator.
• As HC-05 Bluetooth module has a 3.3V level for RX/TX and the microcontroller can detect the 3.3 V level, there is no need to change the transmit level of the HC-05 module. But we need to transfer transmit voltage level from microcontroller to RX of HC-05 module.
• The data transfer rate of HC-05 module can vary up to 1Mbps within 10 meters.
• Automatic connection to the last device: Yes
• Internal antenna: Yes

For this project we need these materials

• 1X Arduino Uno R3;
• 1X Bluetooth HC-05 module;
• 1X BC547 Transistor;
• 1X DC Relay (9V);
• 1X 9V Battery;
• Android App interfacing with HC-05;
• Extra (switch, wires, soldering iron, AC load etc.)

Circuit Schematics

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The HC05-module is a Bluetooth module that uses serial communication, you can create more advanced projects with it.