Bluetooth HC-05

Hi
This article is about giving you an insight on how to interface your HC-05 to your Android powered handset using a bluetooth modem. generally this come without pin & it is very diffficult to connect them as show..

Basic diffierent between them is.....

• The HC-05 module can build a connection to other modules. E.g. a Robot being a master and connecting to slave bluetooth module. Or in slave mode to make a wireless bridge to a notebook.
• The HC-06 module only can be a slave. This makes it only useful for say connecting a notebook as a master to a robot with a slave module e.g. for a wireless serial bridge.

To solve this we generally use JY-MCU as show ....to connect HC-05

• KEY: according to the data sheet, I need to pull-up this pin while power-on-reset of the module to enforce AT mode. I have not been able to verify this yet. I have been told that some modules have this pin not connected at all?
• VCC is indicated in the range of 3.6V-6V. The module worked for me both with 3.3V and 5V.
• GND: Ground
• TXD: serial output of the module, to be connected to RX of the microcontroller. Note that this signal is using 3.3V logic level
• RXD: serial input of the module, to be connected to the TX of the microcontroller. Note that this signal is using 3.3V logic levels.
• STATE: connected to LED2 (Pin32) of the module, but no meaning? At least on my module the pin was always low, regardless if paired or not.

Simple View All connection is......

Now you are ready to evaluate bluetooth........

Happy Bluethoothing............