đây là chương trình mình viết đo nhiệt độ với yêu cầu là Uc= VCC = 5v ( yêu cầy này khó hơn là Uc = 2.56v) và báo động quá nhiệt ở RD0 ( 70 độ) bạn có thể tham khảo
PROCESSOR 16F877A
#INCLUDE<P16F877A.INC>
__CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_ON & _XT_OSC & _WRT_OFF & _LVP_OFF & _CPD_OFF
;================================================= =======================
;KHOI TAO CAC BIEN
;================================================= =======================
CBLOCK 0X020
TRAM
CHUC
DONVI
DEM
DEM1
TAM
ENDC
;------------------------------------------------------------------------
ORG 0000H
;------------------------------------------------------------------------
;KHOI TAO CAC NGO RA
;------------------------------------------------------------------------
BANKSEL TRISB
CLRF TRISB
CLRF TRISE
BCF TRISD,0
BANKSEL PORTB
CLRF PORTB
CLRF PORTE
BCF PORTD,0
;================================================= =======================
MAIN
BSF PORTD,0
CALL DOC_ADC
CALL SOSANH
CALL BCD
CALL QUETLED
GOTO MAIN
;================================================= =======================
SOSANH
CLRF DONVI
CLRF CHUC
CLRF TRAM
CALL DOC_ADC
BANKSEL ADRESL
MOVF ADRESL,W
BANKSEL TAM
MOVWF TAM
BCF STATUS,0
RRF TAM
BCF STATUS,0
MOVLW D'70'
SUBWF TAM,0
BTFSC STATUS,0
GOTO ON
RETURN
;----------------------------------------------------------------------
ON
BCF PORTD,0
RETURN
;================================================= ======================
BCD
MOVLW D'10'
SUBWF TAM,1
BTFSS STATUS,0
GOTO THAP
INCF CHUC,1
MOVLW D'10'
XORWF CHUC,0
BTFSS STATUS,2
GOTO BCD
INCF TRAM,1
MOVLW D'0'
MOVWF CHUC
GOTO BCD
THAP
MOVLW D'10'
ADDWF TAM,0
MOVWF DONVI
RETURN
;----------------------------------------------------------------------
QUETLED
MOVLW B'011'
MOVWF PORTE
MOVF DONVI,W
CALL BANG
MOVWF PORTB
CALL DELAY
MOVLW B'101'
MOVWF PORTE
MOVF CHUC,W
CALL BANG
MOVWF PORTB
CALL DELAY
MOVLW B'110'
MOVWF PORTE
MOVF TRAM,W
CALL BANG
MOVWF PORTB
CALL DELAY
RETURN
;---------------------------------------------------------------------
BANG
ADDWF PCL,1
RETLW B'11000000'
RETLW B'11111001'
RETLW B'10100100'
RETLW B'10110000'
RETLW B'10011001'
RETLW B'10010010'
RETLW B'10000010'
RETLW B'11111000'
RETLW B'10000000'
RETLW B'10010000'
;================================================= ====================
DOC_ADC
BANKSEL PIR1
CLRF PIR1
BSF STATUS,5
BSF ADCON1,3
BSF ADCON1,2
BSF ADCON1,1
BCF ADCON1,0
BCF STATUS,5
BCF ADCON0,5
BCF ADCON0,4
BCF ADCON0,3
BCF ADCON0,7
BCF ADCON0,6
BSF STATUS,5
BSF ADCON1,6
BSF ADCON1,7
BCF STATUS,5
BSF ADCON0,0
BSF ADCON0,2
LOOP2
BCF STATUS,5
BTFSC ADCON0,2
GOTO LOOP2
RETURN
;================================================= ====================
DELAY
BANKSEL OPTION_REG
BCF OPTION_REG,3
BcF OPTION_REG,2
BCF OPTION_REG,1
BsF OPTION_REG,0
BCF STATUS,5
MOVLW D'7'
MOVWF DEM
LOOP1
MOVLW D'17'
MOVWF TMR0
BSF STATUS,5
BCF OPTION_REG,5
BCF STATUS,5
LOOP
BTFSS INTCON,2
GOTO LOOP
BCF INTCON,2
DECFSZ DEM,1
GOTO LOOP1
RETURN
END