BT Shield (Slave)

Overview

BT Shield V2.1 is a Serial port Bluetooth module (Slave) breakout board, and it’s compatible with Arduino and IFlat-32, it can directly plug in with Arduino/IFlat-32 board, use the UART port for communicating to Arduino/IFlat-32 or FT232.

Specifications

Microprocessor	CSR BC417
PCB size	53.3mm X 47mm X 1.6mm
Indicators	PWR,State
Power supply	5V DC
IO	3
Communication Protocol	UART/Bluetooth 2.0
RoSH	Yes

Electrical Characteristics

Specification	Min	Type	Max	Unit
Power Voltage	4.5	5	5.5	VDC
Input Voltage VH (Target Voltage = 3.3V)	3	3.3	3.6	VDC
Input Voltage VH (Target Voltage = 5V)	4.5	5	5.5	V
Input Voltage VL:	-0.3	0	0.5	V
Current Consumption	-	20	40	mA

Hardware

Pad Name	Type	Description
RX/TX	I/O	UART communication Port (Depend on switcher 4)
TX/RX	I/O	UART communication Port (Depend on switcher 4)
State	O	State Direction

Switcher	Name	Description
4	UART Communication Switch	Connect to broad or FT232
5	Communication Voltage Switch	Set the interface voltage

LED	Name	Description
6	PWR	When power on, the PWR LED light.
7	State	\"When the module in standby mode, the State LED will alternating light off. When the serial port open, the State LED light.\"

AT command

Default:

Slave, 9600 baud rate, N, 8, 1. Pincode 1234

AT command:

1. Communications Test:

Sent : AT

receive : OK

2. Change baud rate:

Sent : AT+BAUD1

receive : OK1200

Sent : AT+BAUD2

receive : OK2400

1---------1200

2---------2400

3---------4800

4---------9600

5---------19200

6---------38400

7---------57600

8---------115200

Baud rate setting can be save even power down.

3. Change Bluetooth device name:

Sent : AT+NAMEdevicename

receive : OKname

(devicename is the name you want the device to be , and it will be searched with this name)

Name setting can be save even power down.

4. Change Pincode:

Sent : AT+PINxxxx

receive : OKsetpin

(xxxx is the pin code you set)

Pin code can be save even power down.

Demo Code

unsigned int timeout=0; unsigned char state=0;

ISR(TIMER2_OVF_vect) //Timer2 Service {

TCNT2 = 0; 
timeout++; 
if (timeout>61) 
{ 
state=1; 
timeout=0; 
} 

}

void init_timer2(void) {

TCCR2A |= (1 << WGM21) | (1 << WGM20); 
TCCR2B |= 0x07; // by clk/1024 
ASSR |= (0<<AS2); // Use internal clock - external clock not used in Arduino 
TIMSK2 |= 0x01; //Timer2 Overflow Interrupt Enable 
TCNT2 = 0; 
sei(); 

}

void setup() {

Serial.begin(9600); 
pinMode(2,INPUT); 
pinMode(13,OUTPUT); 
attachInterrupt(0,cleantime,FALLING); 
init_timer2(); 

}

void loop() {

switch(state) 
{ 
case 0: 
digitalWrite(13,LOW); 
break;

case 1:

digitalWrite(13,HIGH); 
Serial.print("Hellow BT"); 
break; 
} 

}

void cleantime() {

timeout=0; 
state=0; 

}