switchdemo.a51

source code for alarming

$NOMOD51
#include "reg66x.h"
NAME            switch_demo
; demo program that interface with the on-board switches, LEDs and LCD screen
; Programmer : A/Prof Soon Ing Yann

EXTRN 			CODE (i2c_init, SPI_init, SC16_init, LCD_init, lcd_wrtdata, lcd_str, lcd_loc, lcd_clr)
PUBLIC 			sw_code, xy, ldata

?STACK          SEGMENT IDATA        
                RSEG    ?STACK       
                DS      30H             ; reserve 30h bytes for stack      
                                     
data_seg_name   SEGMENT DATA            
                RSEG    data_seg_name   
xy:				DS		1				; desired location to write on LCD before provoke LCD_LOC routine
ldata:			DS		1				; 1 character data to write to LCD before provoke LCD_WRTDATA
sw_code:		DS      1				; contains switch data

redled			EQU		P1.0		   ;red led is connected to pin 0 of port 1
blueled			EQU 	P1.4		   ;blue led is connected to pin 4 of port 1

bit_seg_name   	SEGMENT BIT
				RSEG 	bit_seg_name

delay_on:		DBIT	1			   ;not used, for illustration only

                CSEG    AT      0      
                LJMP    start          

code_seg_name   SEGMENT CODE       
                RSEG    code_seg_name  
				USING   0              


line1:			DB		'Hello world !!!$'
line2:			DB		'Welcome to P312$'
line3:          DB      'Switch pressed: $'


;------------------------------------------------------------------------------
; Main program
;------------------------------------------------------------------------------                                 
Start:          MOV     SP,#?STACK-1
				CALL System_init			;system initialisation
				CALL LCD_clr				;clear LCD
				MOV xy, #00h				;display string starts at top line column 0
				MOV DPTR, #line1			;display Hello world 	
				CALL lcd_str	
				MOV xy, #10h				;display string starts at bottom line column 0
				MOV DPTR, #line2			;display welcome to P312
				call lcd_str	
				mov R0, #05h                 ;number of times to blink LEDs

blink:			
				clr redled					;on red led
				clr blueled					;on blue led
				MOV a, #0FFh				;delay LSB in A
				MOV b, #01h					;delay MSB in B
				CALL TimerDelay			    ;short delay to blink led
				setb redled					;off red led
				setb blueled				;off blue led
				MOV a, #0FFh				;delay LSB in A
				MOV b, #02h					;delay MSB in B
				CALL TimerDelay			    ;short delay to blink led
				Dec R0					    ;count counter down
				cjne R0,#0,blink	

repeat:									    ;loop to detect key pressed
			    mov R1,#'1'					;R1 will contains the button number to display
				MOV A, sw_code  			;sw_code contains switch status
loop:	       	RRC	A					    ;Rotate right into carry to check bit by bit 
				JNC disp_key				;check if switch "R1" pressed
				INC R1						;if not increase "R1" to represent the next button
				cjne R1,#'8',loop			; finished
				JMP Repeat
disp_key:	
				MOV xy, #00h				;Set to top line left column
				MOV DPTR, #line3			;display string "key preseed :"at top line 	
				CALL lcd_str				;
				mov xy, #0Fh				;Display button number at last location
				mov ldata, R1
				call lcd_loc				;set Lcd location 
				call lcd_wrtdata			;
				MOV sw_code,#7fh			;Reset sw_code to all off
				jmp repeat


;------------------------------------------------------------------------------
; Initialize the system upon power on
;------------------------------------------------------------------------------
System_init:				
				CALL SPI_init				;initialised Serial Peripheral Interface
				CALL i2c_init				;initialised I2C interface
				SETB EA						;use internal ROM
				CALL LCD_init				;initialised LCD display
				CALL SC16_init				;
				MOV sw_code, #7Fh			;initialise switch status to off
				RET

;------------------------------------------------------------------------------
; Delay routine (Input: A, B)  uses Timer 0
;------------------------------------------------------------------------------
TimerDelay:
				push AR0		;push r0 into stack
				anl tcon,#0cfh  ; Clear T0 overflow & run flags only
				anl tmod,#0f0h  ; T0 enabled; T1 control unchanged
				orl tmod,#01h   ; set T0 to mode 1 (16 bit up counter)
onems:          
				mov TL0, #18h   ;set T0 to count up from FC18h
				mov TH0, #0fch 
				orl TCON, #10h  ;start T0 timer
wait:
				jbc Tf0, dwnab  ; poll T0 overflow flag until set
				sjmp wait       ; loop until Overflow flag set
dwnab:
				anl TCON, #0efh ;stop T0; other TCON bits unchanged
				dec a		    ;count A down
				cjne a, #0ffh, noroll ;
				dec b           ; count B down
noroll:
				mov r0, b
				cjne r0,#00h,onems
done:		    pop AR0			; pop r0 out of stack
				ret


;------------------------------------------------------------------------------
; The END directive is ALWAYS required.
;------------------------------------------------------------------------------
                END             ; End Of File