C and Assembly Code for 8051 based temperarture Monitoring System
INTRODUCTION :
Ladies and Gentlemen, way back couple of weeks I posted a working model for 8051/8052 based temperature monitoring system. The C and Assembly Code was in the pending tray. Please note that the monitoring system includes LCD, the programming for which had also been integrated below. In fact this is the whole program for complete temperature monitoring system. The subject coding for microcontroller 8051 is discussed with sufficient comments below. Moreover if you find any difficulty regarding the coding or the the description, you are more than welcome to contact the owner of this term project at jamalel640@hotmail.com.
CODE :
;OBJECTIVE: TEMPERATURE MONITORING SYSTEM
;THIS PROGRAM DISPLAY TEMPERATURE ON LCD BY USING LM35
;PROGRAMER: JAMAL
;BATCH : 2007
;PROGRAM NAME: TEMPERATURE SENSOR
;MICROCONTROLLER: ATMEL AT89S52
;**************************************************************************************
;........DEFINING VARIABLES..........
ORG 0000H
RS_LCD BIT P1.5 ;pins 1.5,1.6,1.7 of microcontroller
RW_LCD BIT P1.6 ; is connected with register select,
EN_LCD BIT P1.7 ; write and enable pin of lcd
OUTPUT_LCD EQU P3 ; port3 is connected with data pins of
OUTPUT_ADC EQU P2 ; lcd
STR_PTR_ADC EQU 35H ; STR_PTR_ADC is a memory location
CS_ADC BIT P3.0
RD_ADC BIT P3.1
WR_ADC BIT P3.2
INTR_ADC BIT P3.3
;**************************************************************************************
;................MAIN PROGRAM.......................
CLR EN_LCD ; make en=0
CALL SEND_STRING ; call subroutine
HERE: CALL LM35_ADC
CALL SEND_HEX_TO_DEC
SJMP HERE
;**************************************************************************************
;.........ROUTINE FOR DISPLAYING STRING..............
SEND_STRING: CALL INIT_LCD
MOV OUTPUT_LCD,#80H ; address for the first line of lcd
CALL WR_LCD_COMMAND ; call routines to initalize lcd
CALL WAIT_LCD ; call routine to check busy flag
MOV DPTR,#STRING ; move 16 bit string to data pointer
MOV STR_PTR_ADC,#0FFH ; make STR_PTR_ADC an input
STRING_ROUTINE:
INC STR_PTR_ADC
MOV A,STR_PTR_ADC
MOVC A,@A+DPTR ; move string to A
CJNE A,#'$',DISP_AGN ; check the condition
JMP EXIT_LCD_MSG
DISP_AGN: MOV OUTPUT_LCD,A ; move data of A to lcd
SETB RS_LCD ; make rs=1
CLR RW_LCD ; make rw=0
SETB EN_LCD ; apply high to low pulse for writing data
CLR EN_LCD
CALL WAIT_LCD
JMP STRING_ROUTINE
EXIT_LCD_MSG:
RET
;**************************************************************************************
;...........ROUTINE TO CONVERT HEXADECIMAL NUMBER TO DECIMAL NUMBER...........
SEND_HEX_TO_DEC:MOV A,OUTPUT_ADC ; data come from adc data pins
CJNE A,#01100100B,CONVERSION ; jump occurs if A is not equal to 100
MOV B,#10 ; move 10 in B
DIV AB ; process to convert hexadecimal number
MOV R7,B ; into decimal number by dividing by 10
MOV B,#10 ; store the result in registers
DIV AB
MOV R6,B
MOV R5,A
CALL DISPLAY
BACK:
RET
CONVERSION: MOV B,#10
DIV AB
MOV R3,A
MOV OUTPUT_LCD,#8CH ; address to show number on lcd
CALL WR_LCD_COMMAND
CALL WAIT_LCD
MOV A,R3
ADD A,#30H
CALL WR_LCD_DATA ; call subroutine to send data to lcd
MOV A,B
ADD A,#30H ; subtract 30H from A to convert from ascii
CALL WR_LCD_DATA ; character
MOV A,#'C'
CALL WR_LCD_DATA
JMP BACK
DISPLAY: MOV OUTPUT_LCD,#8CH ; address to show number on lcd
CALL WR_LCD_COMMAND
CALL WAIT_LCD
MOV A,R5 ; most significant digit
ADD A,#30H
CALL WR_LCD_DATA
mov A,R6
ADD A,#30H
CALL WR_LCD_DATA
mov A,R7 ; least significant digit
ADD A,#30H
CALL WR_LCD_DATA
MOV A,#'C'
CALL WR_LCD_DATA
RET
;**************************************************************************************
;...........ROUTINE FOR INITALIZATION OF LCD.............
INIT_LCD: MOV R0,#04H ; loop to initalize to lines of lcd
MOV OUTPUT_LCD,#38H ; by sending 38H
AGAIN: CALL WR_LCD_COMMAND
DJNZ R0,AGAIN
CALL WAIT_LCD
MOV OUTPUT_LCD,#0EH ; display on,cursor on
CALL WR_LCD_COMMAND
CALL WAIT_LCD
MOV OUTPUT_LCD,#01H ; clear lcd screen
CALL WR_LCD_COMMAND
CALL WAIT_LCD
RET
;**************************************************************************************
;.......... ROUTINE FOR SENDING COMMANDS TO LCD.............
WR_LCD_COMMAND: CLR RS_LCD ; commands are sent by making rs=0,
CLR RW_LCD ; rw=0, and high to low pulse on
SETB EN_LCD ; enable pin
CLR EN_LCD
RET
;**************************************************************************************
;..........ROUTINE FOR SENDING DATA TO LCD..................
WR_LCD_DATA: MOV OUTPUT_LCD,A
SETB RS_LCD ; commands are sent by making rs=1,
CLR RW_LCD ; rw=0, and high to low pulse on
SETB EN_LCD ; enable pin
CLR EN_LCD
CALL WAIT_LCD
RET
;**************************************************************************************
;..........ROUTINE FOR CHECKING BUSY FLAG OF LCD.............
WAIT_LCD: MOV OUTPUT_LCD,#0FFH ; make port 3 an input port
CLR EN_LCD
CLR RS_LCD
SETB RW_LCD
SETB EN_LCD
MOV A,OUTPUT_LCD
JB ACC.7,WAIT_LCD
CLR EN_LCD ; clear the enable for other commands
ret
;*************************************************************************************
;........... STRING TO BE DISPALYED ON LCD.....................
ORG 100H
STRING: DB 'TEMPERATURE=$' ; string end with a null character
; $ sign shows end of string
;*************************************************************************************
;............TEMPERATURE FROM LM35 INTO ADC..........................
LM35_ADC: MOV OUTPUT_ADC,#0FFH ; make port2 an input port
SETB INTR_ADC
CLR CS_ADC
SETB RD_ADC
CLR WR_ADC
SETB WR_ADC
JB INTR_ADC,$
CLR RD_ADC
NOP
SETB CS_ADC
RET
;*************************************************************************************
END ; end of program
Posted by Unknown
on 17:47. Filed under
Electronics Projects,
Microcontroller,
Temperature Monitoring System
.
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