In this simple(basic) project one can learn interfacing Bluetooth with Arduino. Control your LEDs and buzzer using an app installed in smartphone. By sending data ( character "a" in our case) LEDs will glow and buzzer will sound.
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Step 1: All You Need Is-
Arduino Uno(or clone),
resistors 1k ohm - 3 numbers,
A 9v battery if needed,
A smart phone with Bluetooth terminal app.
Step 2: Testing Bluetooth Module
Connect +5V of HC05 to 3.3V,Rx of module to Tx of Arduino and Tx of module to Rx of Arduino. Ground the gnd pin. After connecting these pins, power the Arduino. Blinking of LED in Bluetooth module ensures working status.
Step 3: Connection
Connect the LED 1 to pin 13 through a resistor(1k),LED 2 to pin 8 through a resistor(1k),LED 3 to pin 7 through a resistor(1k) and ground the other(shorter edge). Positive end of Buzzer is connected to pin 4 and another pin is grounded.
Connection of Bluetooth module:
Connect +5V of HC05 to 3.3V,Rx of module to Tx of Arduino and Tx of module to Rx of Arduino. Ground the gnd pin.
Step 4: Coding
char inChar = (char)Serial.read();
inputString += inChar;
cache = Serial.read();
if(inputString == "a")
else if(inputString == "b")
inputString = "";
Follow the link to attach the code:
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Step 5: Handling It With Smartphone
Download Bluetooth terminal app from Google playstore. It is available for free. On opening connect your smartphone with hc05 through Bluetooth. Now send the data to the Arduino. Data in our case is character "a"and character "b". Sending "a" will blink the three LEDs and will sound the buzzer. By sending"b" all the above action stops.