Interfacing Bluetooth with 8051

Interfacing Bluetooth with 8051 Microcontrollers www.pantechsolu tions.net

WHAT IS BLUETOOTH? • Bluetooth is a proprietary open wireless protocol for exchanging data over short distances (using short length radio waves) from fixed and mobile devices, creating personal area networks (PANs). It was originally conceived as a wireless alternative to RS-232 data cables.

• BlueTooth is a promising standard for short sho rt range wireless communication. BlueTooth uses the same frequency as WaveLan but with much less effect but anyhow some claim that a WaveLan can not co-exist with a fully equiped BlueTooth environment.

• Bluetooth is a wireless technology for transmission of voice and data over a short distance.

• RXD and TXD pin of bluetooth Evaluation kit connected with the controller through serial port

Bluetooth interface board

Bluetooth interface HELLO  blue2th

2.4GHz RF Communi cation e b X O L L E H

!

e

8051

Bluetooth interface with 8051

BLUETOOTH INTERFACE ASSEMBLY CODE connection details 1) Connect first bluetooth module to the PC 2) Connect the second blue tooth module to 8051 using s erial port cable execute the program the massage is  being transferred Write a program to transfer the message “YES” serially at 9600 baud, 8bit data, 1 stop bit interfacing with BLUETOOTH module. Do this continuously. Solution: MOV TMOD,#20H ;timer 1, mode 2 MOV TH1,#-3 ;9600 baud MOV SCON,#50H ;8-bit, 1 stop bit, REN enabled SETB TR1 ;start timer 1 AGN: MOV A,#"Y" ;transfer "Y" ACALL XMIT MOV A,#"E" ;transfer "E" RET ACALL XMIT MOV A,#"S" ;transfer "S" ACALL XMIT SJMP AGN ;keep doing it ;serial data transfer subroutine XMIT: MOV SBUF,A ;load SBUF HERE: JNB TI,HERE ;wait for last bit to transfer   CLR TI ;get ready for next byte

BLUETOOTH INTERFACE C CODE // program to accept commands commands from PC via Bluetooth // USB-Bluetooth adapter is connected connected to PC // here Bluetooth module module is interfaced with 89C51 #include void delay(unsigned long); void send command(unsigned char array[]); void transmit(unsigned char); unsigned code char setcon[]="set connectable on"; void main() { send_command(setcon); delay(50000); while(1) { TMOD=0X20; TH1=0XFD; SCON=0X50; TR1=1; SBUF=dat; while(TI==0) {} } void delay(unsigned long count) { unsigned long i; for(i=0;i
C CODE CONTD void send_command(unsigned char array[]) { unsigned char i; TMOD=0X20; TH1=0XFD; SCON=0X50; TR1=1;

for(i=0;array[i]!='\0';i++) { SBUF=array[i]; while(TI==0) { TI=0; }

SBUF=0x0D; while(TI==0) {} TI=0; SBUF='\n'; while(TI==0) {} TI=0; }

// baud 9600Kbps @ 11.0592 Mhz

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