Файл: Microcontroller Programming. Thi Micro Chip PIC (Julio Sanchez, 2007).pdf

#include <p16f877.inc>

__CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_ON & _HS_OSC & _WDT_OFF & _LVP_OFF & _CPD_OFF

;__CONFIG directive is used to embed configuration data

;within the source file. The labels following the directive

;are located in the corresponding .inc file.

errorlevel -302

; Suppress bank-related warning

;============================================================

; M A C R O S

;============================================================ ; Macros to select the register banks

;=====================================================

; constant definitions

; for PIC-to-LCD pin wiring and LCD line addresses ;=====================================================

#define LCDlimit .20; Number of characters per line #define spbrgVal .64; For 2400 baud on 10Mhz clock

;Note: The constants that define the LCD display

;line addresses have the high-order bit set

;so as to meet the requirements of controller

;commands.

;==========================================================

;constants for I2C initialization ;==========================================================

;I2C connected to 24LC04B EEPROM.

;The MSSP module is in I2C MASTER mode.

#define LC04READ 0xa0 ; I2C value for read control byte #define LC04WRITE 0xa1 ; I2C value for write control byte

;========================================================== ; General Purpose Variables ;==========================================================

;Local variables

;Reserve 20 bytes for string buffer cblock 0x20

strData endc

;Other data

;

;==============================

;Common RAM area ;==============================

;These GPRs can be accessed from any bank.

;15 bytes are available, from 0x70 to 0x7f

errorFlags

; EEPROM-related variables

EEMemAdd ; EEPROM address to access

;Wiring:

;LCD data to Port-D, lines 0 to 7

;E line -> Port-E, 1

;RW line -> Port-E, 2

;RS line -> Port-E, 0

;Set PORTE D and E for output

;First, initialize Port-B by clearing latches clrf STATUS

clrf PORTB

;Select bank 1 to TRIS Port-D for output Bank1

;TRIS Port-D for output. Port-D lines 4 to 7 are wired

;to LCD data lines. Port-D lines 0 to 4 are wired to LEDs.

movlw B’00000000’

;By default Port-A lines are analog. To configure them

;as digital code must set bits 1 and 2 of the ADCON1

;register (in bank 1)

; make all Port-A lines digital

movwf ADCON1

;Port-B, lines are wired to keypad switches, as follows:

;7 6 5 4 3 2 1 0

;| | | | |_|_|_|_____ switch rows (output)

;|_|_|_|_____________ switch columns (input)

;rows must be defined as output and columns as input

; Enable Port-B pullups for switches in OPTION register movlw b’00001000’

movwf OPTION_REG

;Back to bank 0 Bank0

;Initialize serial port for 2400 baud, 8 bits, no parity

;1 stop

call InitSerial

; Test serial transmission by sending “RDY-”

;============================================================

;receive serial data, store, and display ;============================================================ receive:

;Call serial receive procedure

call SerialRcv

;HOB of newData register is set if new data

;received

btfss newData,7

;============================

;display EEPROM data ;============================

;This routine receives control when the <Enter> key is

;received.

;Action:

;1. Clear LCD

;2. Output is set to top LCD line

;3. Characters stored in EEPROM are displayed

;until 0x0d code is detected

isEnter:

call clearLCD

; Clear character counter and line counter variables clrf LCDcount

clrf LCDline

;Read data from EEPROM memory, starting at address 0

;and display on LCD until 0x0d terminator

;At this point character read is not 0x0d

;Display on LCD