HC05 bluetooth module will not appear in Available devices when searching to pair on andriod device

Bluetooth module will not appear in available devices when trying to connect on an android device. or any device for that matter doesn't show up at ALL no devices found.

I unplug the RX and TX cables before uploading and then plug them back in but still nothing.

I've followed ( Arduino and HC-05 Bluetooth Module Tutorial | Android Smartphone & Laptop Control - YouTube ) and various other tutorials is there something crucial I'm missing in the setup or do I have a LEMON.

using Arduino mega 2560

Rx0(0) --> Tx

Tx0(1) --> Rx

5v - +5v


#define ledPin 11

int state = 0 ;

void setup(){

void loop() {
if(Serial.available() >0){
state = Serial.read();

if (state == '0'){
Serial.println("LED: OFF");
state = 0;
else if(state == '1'){
Serial.println("LED: ON");
state = 1;


If the HC-05 is configured as a 'slave' then all it needs is power (in order to pair with an Android/mobile).

The HC05 not appearing or pairing with an Android device is not an Arduino problem. The code on the Arduino to which the HC05 is connected should have no effect on if it can be seen by Bluetooth devices.

Once you do have it paired with a Bluetooth device and connected to an app on the device the communication mode baud rate is usually 9600 baud. 38400 baud is for AT mode.

As mentioned above, Arduino is not involved with pairing, and your code is probably not kosher anyway. All you need is the LED flashing about 2Hz. Is that happening? If not, shut down and start over. Don't push any buttons...

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