1_4

1_4

the purpose of this week is setting Bluetooth enter AT mode and make Bluetooth can communicate between the processor and computer. 

Hardware requirements:

1.     Two Bluetooth (HC-05).

2.     USB conversion port

Figure 1: the Bluetooth HC-05 (with black button) and USB conversion port

                                                                

Figure 2: the Bluetooth HC-05 (without black button) 

Software requirements:

1.     Arduino 1.8-3

Connection requirements:

HC-05	USB conversion port
RX	TXD
TX	RXD
VCC	VCC
GND	GND

AT command

1.     AT+NAME=LSN  (setting the Bluetooth name to LSN)

2.     AT+ROLE=1     (setting the Bluetooth role to master, 1 is master and 0 is slaver)                       

3.     AT+PSWD=1234  (setting the password to 1234)           

4.     AT+UART=115200，0，0 (setting the baud rate to 115200 and Stop bit 1 bit, no parity bit)

Create a new program in the Arduino, then open the serial monitor, adjust the baud rate to 38400, because the Bluetooth HC-05 initial baud rate is 38400. Then enter the AT command, if successful, feedback OK, failure feedback error.

Conclusion

The HC-05 comes in two styles; one with a black button and one without a black button. Make sure you buy Bluetooth with a black button. Because when you enter AT mode, you need to press and hold the black button to power on.