Application of general synchronous/asynchronous communication (2)

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Application of general synchronous/asynchronous communication (2) [Copy link]

Single chip dual machine synchronous communication

1 PIC1 microcontroller programming (master control sending)

#include <pic.h>

/* This program realizes the synchronous communication function of two MCUs, which is the main control sending part. The program will display after power on.

* Corresponding characters indicate that the system is working properly. The sent data will be displayed after sending */

unsigned char tran[8] ; /* define an array to store the sent data */

unsigned char k , data ; /* define general register */

const char table[20]={0xc0 , 0xf9 , 0xa4 , 0xb0 , 0x99 , 0x92 , 0x82 , 0XD8 , 0x80 , 0x90 , 0x88 , 0x83 , 0xc6 , 0xa1 , 0x86 , 0x8e , 0x7f, 0xbf , 0x89 , 0xff} ;

/* Display segment code table without decimal point */

/*spi display initialization subroutine */

void SPIINIT()

{

; For detailed program statements, please refer to Section 8.5 of this chapter

}

/* Subroutine to assign initial value to the sending array */

void fuzhi()

{

for(k=0 ; k<8 ; k++){

tran[k]=k ;

} /* Send eight data from 0 to 7 */

}

/*SCI component initialization subroutine */

void sciint()

{

SPBRG = 200 ; /* Set the baud rate of the transmission to about 9600 bits / second */

TXSTA=0X90 ; /* Select master control mode */

RCSTA=0X80 ; /* Enable synchronous serial port to work */

TRISC6=1 ;

TRISC7=1 ; /* Set RC6 and RC7 to input mode, and present high impedance to the outside */

}

/*SPI data transfer subroutine */

void SPILED(data)

{

; For detailed program statements, please refer to Section 8.5 of this chapter

}

/* Display subroutine, display 8 digits */

void display()

{

RA5=0 ; /* Ready to latch */

for(k=0 ; k<8 ; k++){

data = tran[k] ;

data=table[data] ; /* get the displayed segment code */

SPILED(data) ; /* Send display segment code */

}

RA5=1 ; /* Finally, a latch signal is given to indicate that the task is completed */

}

/* Display subroutine, display 8 digits */

void display1()

{

RA5=0 ; /* Ready to latch */

for(k=0 ; k<8 ; k++){

data=0xf9 ; /* Displaying "1" means the system is working normally */

SPILED(data) ; /* Send display segment code */

}

RA5=1 ; /* Finally, a latch signal is given to indicate that the task is completed */

}

/* Main program */

main()

{

SPIINIT() ; /*spi display initialization */

fuzhi()；/* Assign the initial value to the sending array */

sciint() ; /*SCI component initialization */

di() ; /* interrupt disable */

TXEN=1 ; /* Transmitting enabled */

display1()；/* Display the corresponding characters, indicating that the system is normal */

while(1){

for(k=0 ; k<8 ; k++){

TXREG = tran[k] ; /* Send a character */

while(1){

if(TXIF==1) break ;

} /* Wait for the previous data to be written */

}

display() ; /* Display the sent data */

} /* Send in loop */

}

2 MCU PIC2 programming (slave reception)

#include <pic.h>

/* This program realizes the synchronous communication function of two MCUs , and is the slave receiving part. It displays the received data

* Displayed on 8 LEDs * /

unsigned char rece[8] ; /* define an array to store received data */

unsigned char k , data ; /* define general register */

unsigned int i ;

const char table[20]={0xc0 , 0xf9 , 0xa4 , 0xb0 , 0x99 , 0x92 , 0x82 , 0XD8 , 0x80 , 0x90 , 0x88 , 0x83 , 0xc6 , 0xa1 , 0x86 , 0x8e , 0x7f, 0xbf , 0x89 , 0xff} ;

/* Display segment code table without decimal point */

/*spi display initialization subroutine */

void SPIINIT()

{

; For detailed program statements, please refer to Section 8.5 of this chapter

}

/*SCI component initialization subroutine */

void sciint()

{

TXSTA=0X10 ; /* Select synchronous slave mode */

RCSTA=0X90 ; /* Serial port operation enable */

TRISC6=1 ;

TRISC7=1 ; /* Set RC6 and RC7 to input mode and present high impedance to the outside */

}

/*SPI data transfer subroutine */

void SPILED(data)

{

; /* For detailed program statements, please refer to Section 8.5 of this chapter */

}

/* Display subroutine, display 4 digits */

void display()

{

RA5=0 ; /* Ready to latch */

for(k=0 ; k<8 ; k++){

data = rece[k] ;

data=table[data] ; /* get the displayed segment code */

SPILED(data) ; /* Send display segment code */

}

RA5=1 ; /* Finally, a latch signal is given to indicate that the task is completed */

}

/* Main program */

main()

{

SPIINIT() ; /*spi display initialization */

sciint() ; /*SCI component initialization */

di() ; /* interrupt disable */

CREN=1 ; /* Receive enabled */

for(k=0 ; k<8 ; k++) rece[k]=0x03 ;

display()； /* Display data indicating normal operation of the system */

while(1) {

while(1){

CREN=1 ; /* Enable continuous reception */

while(1){

if(RCIF==1) break ;

} /* Wait for receiving data */

k=0 ;

rece[k]=RCREG ; /* Read received data */

if(OERR==1) { /* If there is an overflow error , handle it */

CREN=0 ;

CREN=1 ;

}

if(rece[k]==0x00) break ; /* “0 ”For synchronization characters , only when "0 ”The following reception is performed only when

}

for(k=1 ; k<8 ; k++){

while(1){

if(RCIF==1) break ;

} /* Wait for receiving data */

rece[k]=RCREG ; /* Read received data */

if(OERR==1) { /* If there is an overflow error , handle it */

CREN=0 ;

CREN=1 ;

}

rece[k]=rece[k]&0x0F; /* Shield the high bit to prevent interference */

}

CREN=0 ;

display()；/* Display received data */

for(i=65535 ; --i ; )continue ;

for(i=65535 ; --i ; ) continue ; /* Give a certain delay before the next round of receiving */

}