[ บทความ : ตัวอย่างโปรแกรมของ CP-PIC877 V1/V2 ] ตอนที่ 1 การติดต่อกับ RS232

ตัวอย่างต่อไปนี้เป็น โปรแกรมที่เขียนขึ้นเพื่อใช้งานกับบอร์ด CP-PIC877 V1 หรือ V2 ของบริษัท ETT ตัวอย่าง นี้เป็นการติดต่อกับพอร์ต RS232 โดยเราสามารถเขียนเป็นภาษาแอสเซมบลีได้ดังนี้

;********************************************** ; Test RS232 or RS422(Single node) ; Hardware : CP-PIC877 V1.0 & V2.0 ; file name : 232.ASM ; Assembler : mpasm.exe ; Programmer: Somkiat Siha ; Company : ETT CO.,LTD. ; Date : 19/2/2000 ;********************************************** ; STEP to follow when test this program ; 1.Connect RS232 or RS422 cable between board and PC. ; 2.Download this program to CPU. ; 3.Run terminal program such as Procom plus,XTALK etc. ; 4.Set parameter Procom plus to 2400 baud,No parity,8 bits data and 1 bit. stop ; 5.Reset board ,after reset board you will see this message on PC. ; " CP-PIC877 V1.0 & V2.0" ; " ETT CO.,LTD." ; 6.Press any key on keyboard, you will see the key that you pressed. ;********************************************** list p=16f877 ; list directive to define processor #include ; processor specific variable definitions __CONFIG _CP_OFF & _WDT_OFF & _BODEN_ON & _PWRTE_ON & _XT_OSC & _WRT_ENABLE_ON & _LVP_ON & _DEBUG_OFF & _CPD_OFF offset EQU 0x20 temp EQU 0x21 ORG 0x0000 ;************ initial ******************* init bsf STATUS,RP0 ; select bank 1 clrf TRISD movlw 0x19 ; BAUD rate 2400 movwf SPBRG clrf TXSTA ; 8 bits data ,no,1 stop bcf STATUS,RP0 ; select bank 0 bsf RCSTA,SPEN ; Asynchronous serial port enable bsf RCSTA,CREN ; continuous receive bsf STATUS,RP0 ; select bank 1 bsf TXSTA,TXEN ; Transmit enable bcf STATUS,RP0 ; select bank 0 ;********** start to send ********************** clrf offset ; load offset of character table start movf offset,w call TAB addlw 0 ; Character = 00 ? btfsc STATUS,Z ; Character = 00 ? goto wait2 ; Yes , Z = 1 ; No , Z = 0 movwf TXREG ; Send recent data to TX wait1 movlw TXSTA ; movwf FSR ; FSR <= TXSTA btfss INDF,1 ; check TRMT bit in TXSTA (FSR) goto wait1 ; TXREG full or TRMT = 0 incf offset,f ; TXREG empty or TRMT = 1 goto start ; Send again ;********** start to receive ******************* wait2 btfss PIR1,RCIF ; Check RCIF bit in PIR1 register goto wait2 ; RCREG empty or RCIF = 0 movf RCREG,w ; RCREG full or RCIF = 1 movwf TXREG goto wait2 ;********* Tebel of message ******************** TAB addwf PCL ; Move offset to PC lower retlw "C" retlw "P" retlw "-" retlw "P" retlw "I" retlw "C" retlw "8" retlw "7" retlw "7" retlw " " retlw "V" retlw "1" retlw "." retlw "0" retlw " " retlw "&" retlw " " retlw "V" retlw "2" retlw "." retlw "0" retlw 0xA retlw 0xD retlw "E" retlw "T" retlw "T" retlw " " retlw "C" retlw "O" retlw "." retlw "," retlw "L" retlw "T" retlw "D" retlw "." retlw " " retlw 0xA retlw 0xD retlw 0 END

สำหรับใครที่ใช้ PIC BASIC Pro ก็สามารถเขียนโปรแกรมได้ดังนี้

'********************************************* 'Test RS-232 or RS-422 'Hardware : CP-PIC877 V1.0 & V2.0 'file name : PicBasic Pro compiler (PBP.EXE) 'Programmer : Somkiat Siha 'Company : ETT CO.,LTD. ' Date : 20/2/2000 '********************************************* ' After down load this program complete. ' 1. Connect RS232 cable between PC & board. ' 2. Run program terminal such as Procom Plus and set parameters follow ' 9600 Baud, 8 bits data, 1 stop ,No parity ' 3. Then press anykey(PC) you will see data that you press on screen(it echo) INN var byte include "bs2defs.bas" loop: serin portc.7,T9600,INN serout portc.6,T9600,[INN] goto loop end

LiNK :

CP-PIC877 V1
CP-PIC877 V2