PIC16F883單片機EUSART串口通訊

在兩個單片機之間創建串口通訊。

說明：咱們使用數碼管顯示接收到的數據，數據是對方的按鍵編號。

硬件鏈接圖：

有一點相當重要，就是兩個單片機要共地。發送和接收引腳在兩個單片機上交叉相連。

這裏採用的是異步發送和接收。

發送原理圖：

EUSART接收圖：

 

時序圖：

 

實現代碼流程圖：

 

實現代碼：

#include<p16f883.inc>

 

    __CONFIG    _CONFIG1, _LVP_OFF & _FCMEN_ON & _IESO_OFF & _BOR_OFF & _CPD_OFF & _CP_OFF & _MCLRE_ON & _PWRTE_ON & _WDT_OFF & _INTRC_OSC_NOCLKOUT

    __CONFIG    _CONFIG2, _WRT_OFF & _BOR21V

 

udata_shr

counter res 1

counter1 res 1 ;掃描按鍵變量

counter2 res 1 ;延時程序微調參數

key_state res 1 ;按鍵狀態

keynum res 1 ;按鍵標號

swap res 1 ;確認按鍵轉換值

keypress res 1

keypressbak res 1

keyrelease res 1

LED1 res 1

LED2 res 1

LED3 res 1

LED4 res 1

 

    UDATA

counter3 res 1

counter4 res 1

sign res 1

 

 

reset code 0x0000

pagesel start

goto start

 

;int_vector code 0x0004

code

start

banksel ANSEL ;設置PORTA爲數字模式

clrf ANSEL

banksel ANSELH ;設置PORTB爲數字模式

clrf ANSELH

banksel TRISB ;設置PORTB爲輸入模式

movlw b'11111111'

movwf TRISB

banksel WPUB ;設置PORTB弱上拉

movlw b'11111111'

movwf WPUB

banksel OPTION_REG

movlw b'01000101' ;TMR0 64分頻

movwf OPTION_REG

banksel T1CON

movlw b'10010001' ;打開TMR1，設置1:8預分頻，內部時鐘源1:4分頻

movwf T1CON

banksel TRISA ;設置PORTA<3:0>爲輸出，接數碼管的共陰極

movlw b'11100000'

movwf TRISA

banksel PORTA

clrf PORTA

banksel TRISC

movlw b'00000000' ;設置PORTC爲輸出，接8段數碼管

movwf TRISC

clrf counter1

;***************************************

;串口發送配置

banksel TXSTA

movlw b'10100100'

movwf TXSTA

banksel BAUDCTL

movlw b'00000001'

movwf BAUDCTL

banksel SPBRG ;設置波特率

movlw d'25'

movwf SPBRG

banksel RCSTA

movlw b'10010000'

movwf RCSTA

 

;***************************************

loop

movlw HIGH Table1

movwf PCLATH

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

movf counter1,0

call Table1

banksel PORTB

movwf PORTB

movf PORTB,0

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

 

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto case1

 

incf counter1,1

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

movf counter1,0

call Table1

banksel PORTB

movwf PORTB

movf PORTB,0 ;讀取I/O狀態

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto case2

 

incf counter1,1

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

movf counter1,0

call Table1

banksel PORTB

movwf PORTB

movf PORTB,0 ;讀取I/O狀態

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto case3

 

incf counter1,1

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

movf counter1,0

call Table1

banksel PORTB

movwf PORTB

movf PORTB,0 ;讀取I/O狀態

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto case4

goto continue

 

case1

btfsc key_state,4

goto key2

movlw d'1'

movwf keynum

call DealKeyPress

goto continue

key2

btfsc key_state,2

goto key3

movlw d'2'

movwf keynum

call DealKeyPress

goto continue

key3

btfsc key_state,1

goto key4

movlw d'3'

movwf keynum

call DealKeyPress

goto continue

key4

btfsc key_state,0

goto continue

movlw d'4'

movwf keynum

call DealKeyPress

goto continue

 

 

 

 

case2

;-------------------------------------------------

;下面代碼實現K10\K8\K5的按鍵處理

btfsc key_state,2

goto key8

movlw d'10'

movwf keynum

call DealKeyPress

goto continue

;------------------------------------

;處理K8

key8

btfsc key_state,1

goto key5

movlw d'8'

movwf keynum

call DealKeyPress

goto continue

;------------------------------------

;處理K5

key5

btfsc key_state,0

goto case3

movlw d'5'

movwf keynum

call DealKeyPress

goto continue

 

case3

;----------------------------------

;處理K6/K9

btfsc key_state,1

goto key6

movlw d'9'

movwf keynum

call DealKeyPress

goto continue

key6

btfsc key_state,0

goto case4

movlw d'6'

movwf keynum

call DealKeyPress

goto continue

case4

;-----------------------------------------

;處理K7

btfsc key_state,0

goto continue

movlw d'7'

movwf keynum

call DealKeyPress

 

continue

banksel PIR1

btfss PIR1,RCIF ;檢測有無收到數據

goto lOOP2

call receive

lOOP2

call display

clrf counter1

goto loop

 

 

;-----------------------------------

;按鍵去抖，約8mS

delay

movlw d'4'

movwf counter2

LOOP2

banksel TMR0

clrf TMR0

LOOP1

banksel INTCON

btfss INTCON,T0IF

goto LOOP1

bcf INTCON,T0IF

decfsz counter2,1

goto LOOP2

return

 

delay2

incfsz counter3,1

goto delay2

return

 

;--------------------------------

;按鍵處理程序

;

DealKeyPress

clrf LED1

clrf LED2

clrf LED3

; clrf LED4

call delay

 

banksel TMR1H

clrf TMR1H

banksel TMR1L

clrf TMR1L

clrf keypress

presstime

banksel PIR1

btfss PIR1,TMR1IF

goto next

bcf PIR1,TMR1IF

incf keypress

movlw d'2'

subwf keypress,0

banksel STATUS

btfsc STATUS,C

goto longpress

next

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

banksel PORTB

movwf PORTB

movf PORTB,0 ;讀取I/O狀態

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto presstime


call delay

 

banksel TMR1H

clrf TMR1H

banksel TMR1L

clrf TMR1L

clrf keyrelease

releasetime

banksel PIR1

btfss PIR1,TMR1IF

goto next1

bcf PIR1,TMR1IF

incf keyrelease

movlw d'1'

subwf keyrelease,0

banksel STATUS

btfsc STATUS,C

goto click

next1

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

banksel PORTB

movwf PORTB

movf PORTB,0 ;讀取I/O狀態

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto over

goto releasetime

over

call delay

banksel TMR1H

clrf TMR1H

banksel TMR1L

clrf TMR1L

clrf keypress

presstime1

banksel PIR1

btfss PIR1,TMR1IF

goto next2

bcf PIR1,TMR1IF

incf keypress

movlw d'1'

subwf keypress,0

banksel STATUS

btfsc STATUS,C

goto click

next2

movf counter1,0

call Table1

banksel TRISB

movwf TRISB

banksel PORTB

movwf PORTB

movf PORTB,0 ;讀取I/O狀態

movwf key_state

movlw b'11001000'

iorwf key_state,1

movf counter1,0

call Table1

xorwf key_state,0

movwf swap

comf swap,1

incfsz swap,1

goto presstime1

movf keynum,0

movwf LED1

goto back

longpress ;長按計數清零

goto back

click

movf keynum,0

movwf LED1

back

;*********************************

;發送按鍵編號


banksel PIR1

lOOP

btfss PIR1,TXIF

goto lOOP

movf LED1,0

banksel TXREG

movwf TXREG

banksel TXSTA 

lOOP1

btfss TXSTA,TRMT

goto lOOP1

 

;*********************************

return

 

;--------------------------------

;顯示數碼管

;

display

banksel PORTA

movlw b'11111110'

movwf PORTA

movf LED1,0

call Table3

banksel PORTC

movwf PORTC

movwf counter

btfss counter,6

goto lOOP5

banksel PORTA

bsf PORTA,4

goto next4

lOOP5

banksel PORTA

bcf PORTA,4

next4

call delay2

 

banksel PORTA

movlw b'11110111'

movwf PORTA

movf LED4,0

call Table3

banksel PORTC

movwf PORTC

movwf counter

btfss counter,6

goto lOOP6

banksel PORTA

bsf PORTA,4

goto next5

lOOP6

banksel PORTA

bcf PORTA,4

next5

call delay2

return

 

receive

;*********************************

;接收按鍵編號

banksel RCREG

movf RCREG,0

movwf LED4

return

;*********************************

 

;----------------------

;Table真值表

;

Table1 ;PORTB、TRISB掃描配置信息

    ADDWF   PCL,f

    RETLW   B'11111111' 

    RETLW   B'11101111'

    RETLW   B'11111011'

    RETLW   B'11111101'

     

Table3 ;PORTC設置，數碼管真值表

    ADDWF   PCL,f

    RETLW   B'00111111' ;0

    RETLW   B'00000110' ;1

    RETLW   B'01011011' ;2

    RETLW   B'01001111' ;3

    RETLW   B'01100110' ;4

    RETLW   B'01101101' ;5

    RETLW   B'01111101' ;6

    RETLW   B'00000111' ;7

    RETLW   B'01111111' ;8

    RETLW   B'01101111' ;9

    RETLW   B'00111111' ;0

end

按鍵檢測前面有博文講解，數碼管程序比較簡單。老師要求咱們用中斷實現，不過因爲咱們以前的實驗總在中斷那裏出問題咱們就沒有用中斷。

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