HC-06 bluetooth module

Question

I need help with the blinking LED of my HC-06 Bluetooth module.

I just want to know what it means when it starts blinking, when it's always on and when it's not on at all and how do I know if it's connected or paired by the LED.

My second question is that I'm developing an Android app that sends data to an Arduino UNO board via this Bluetooth module, but every time I try to send my data, the app crashes.

Answer 1

The blinking LED means that it's waiting to be connected. When it stops blinking, the connection is established.

Check this great tutorial here.

Answer 2

if the led is not on at all, probably the unit doesn't receive power. if the led is blinking, it's not connected ( it will continue blink after you've paired it) if the led is solid on, it's connected ( to some kind of communication, such as a bluetooth terminal)

so don't worry if you pair it with your android or laptop and the blinking continues.

the easy way to check that it's working is to give it power on the vcc pin and connect rx with tx, now you can send a byte from a laptop or android, and you should immediately receive the same byte. i've found both Tera Term and Termite 3.1 to work on windows 8 on android i've found "Bluetooth Terminal" by "Juan Sebastian Ochoa Zambrano" to work but "Bluetooth Terminal" by "Qwerty" doesn't work for me on Android.

On the computer you will choose a com-port, the default baudrate is 9600. you can check which com-port it's on in the device manager

Don't confuse HC-06 with HC-05, they work in different ways.

if you use the module on a breakout, it probably has a voltage regulator that takes whatever you put on vcc down to 3.3V, it's a good idea to give it 5V on vcc pin in that case, giving it 3.3V on vcc causes strange behaviour in some cases