;************************************************************************* ; Read data from 000 to FFF, from a serial EEPROM 24C32 ; PORTA to jump to a specific address or sequential inc-dec ; character address Hexadecimal ; LCD line1: 01001101 addr ; LCD line2: M 4D 000 ; ; PIC16F84 XT=8MHZ ; Lakra Karim 23.06.2015 ; LCD HD44780 ; RB0-RB3 connected to LCD D4-D7, RB4->E, RB5->RS, R/W->GND ; RB7 to SDA, RB6 to SCL ; RA0 for previous address, RA1 for next address ; RA2 increment selected bit address, RA3 decrement selected bit address ; RA4 next bit address going from left to right (addr bit2 to bit0) then back to bit2 ;************************************************************************* ;****************** COMPILATION MESSAGES & WARNINGS ********************* ;ERRORLEVEL -207 ; Found label after column 1. ERRORLEVEL -302 ; Register in operand not in bank 0. ; ERRORLEVEL -205 ; Found directive in column 1 ; ERRORLEVEL -202 ; Argument out of range. Least significant bits used. ;***** PROCESSOR DECLARATION & CONFIGURATION ***** PROCESSOR 16F84 #include "p16f84.inc" ; embed Configuration Data within .asm File. __CONFIG _CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC ;*************************** DATA SEGMENT ******************************** CBLOCK 0x00C del, cmd, adrs_LW, adrs_HI ; variables for passing the parameters temp, i, curPOS, bitDATA ; local variables (20h reserved for data, bitDATA for bits entred by the user) ENDC org 0 ; start program at the beginning of mem goto start msg1 ; first message to display addwf PCL, f dt "addr", 0 ;*****Set up the Constants**** STATUS equ 03h ; Address of the STATUS register TRISA equ 85h ; Address of the tristate register for port A PORTA equ 05h ; Address of Port A TRISB equ 86h ; Address of the tristate register for port B PORTB equ 06h ; Address of Port B LINE1 equ 0x80 ; command line1 of LCD LINE2 equ 0xC0 ; command line2 of LCD start bsf STATUS,RP0 ; Switch to Bank 1 movlw b'11111' ; Set the Port A pins RA0-RA4 movwf TRISA ; to intputs clrf TRISB ^ 0x80 ; enable RB0-RB7 for output movlw 0x7F ; enable internal Pull-Ups movwf OPTION_REG ^ 0x80 bcf STATUS, RP0 ; back to BANK 0 call initLCD ; initialize LCD display ;call WRITE_EEPROM goto Main ;output of the top row (msg1) MS1 clrf i L1 movf i, w call msg1 ; get the next char iorlw 0 ; end of string? btfsc STATUS, Z return ; YES - jump out of the loop call writeDATA ; NO - send it to LCD incf i, f ; update the char index goto L1 Main clrf adrs_LW ; clear the address holder clrf adrs_HI clrf bitDATA movlw d'6' ; initialize cursor position for editing movwf curPOS goto READ_EEPROM ;********************************* Buttons press manager A_INC btfss PORTA,0 ; test bit PortA0 if 1 skip next line Call INC ; increment eeprom address, if (A0=0) btfss PORTA,1 ; test PortA1 if 1 skip next line Call DEC ; decrement eeprom address, if (A1=0) btfss PORTA,2 ; test PortA2 if 1 skip next line Call INC_B ; move cursor to next bit address, if (A2=0) btfss PORTA,3 ; test PortA3 if 1 skip next line Call DEC_B ; move cursor to previous bit address, if (A3=0) btfss PORTA,4 ; test PortA4 if 1 skip next line Call OK_B ; select data and address bits for edition goto A_INC ;********************************* Increment bit selector INC_B ; increment selected bit movlw d'6' ; position HI-bit data subwf curPOS,w btfsc STATUS,Z goto BIT_HI_INC movlw d'7' ; position LW-bit data subwf curPOS,w btfsc STATUS,Z goto BIT_LW_INC movlw d'12' ; position of hundreds subwf curPOS,w btfsc STATUS,Z goto BIT_HUNDREDS_INC movlw d'13' ; position of tens subwf curPOS,w btfsc STATUS,Z goto BIT_TENS_INC movlw d'14' ; position of ones subwf curPOS,w btfsc STATUS,Z goto BIT_ONES_INC return ;********************************* Decrement bit selector DEC_B ; decrement selected bit movlw d'6' ; position HI-bit data subwf curPOS,w btfsc STATUS,Z goto BIT_HI_DEC movlw d'7' ; position LW-bit data subwf curPOS,w btfsc STATUS,Z goto BIT_LW_DEC movlw d'12' ; position of hundreds subwf curPOS,w btfsc STATUS,Z goto BIT_HUNDREDS_DEC movlw d'13' ; position of tens subwf curPOS,w btfsc STATUS,Z goto BIT_TENS_DEC movlw d'14' ; position of ones subwf curPOS,w btfsc STATUS,Z goto BIT_ONES_DEC return ;********************************* Data edit bits - Increment BIT_HI_INC movlw 0x10 addwf bitDATA,1 movlw 0xF0 andwf bitDATA,w movwf 21h swapf 21h,1 call HEXA_TO_LCD_WAIT return BIT_LW_INC movf bitDATA,w movwf 21h incf 21h,1 movlw 0x0F andwf 21h,1 movlw 0xF0 andwf bitDATA,1 movf 21h,w addwf bitDATA,1 movwf 21h call HEXA_TO_LCD_WAIT return ;********************************* Data edit bits - Decrement BIT_HI_DEC movlw 0x10 subwf bitDATA,1 movlw 0xF0 andwf bitDATA,w movwf 21h swapf 21h,1 call HEXA_TO_LCD_WAIT return BIT_LW_DEC movf bitDATA,w movwf 21h decf 21h,1 movlw 0x0F andwf 21h,1 movlw 0xF0 andwf bitDATA,1 movf 21h,w addwf bitDATA,1 movwf 21h call HEXA_TO_LCD_WAIT return ;********************************* Address edit bits - Decrement BIT_HUNDREDS_DEC decf adrs_HI,1 movlw 0x0F andwf adrs_HI,1 movlw 0x0F andwf adrs_HI,w movwf 21h call HEXA_TO_LCD_WAIT return BIT_TENS_DEC movlw 0x10 subwf adrs_LW,1 movlw 0xF0 andwf adrs_LW,w movwf 21h swapf 21h,1 call HEXA_TO_LCD_WAIT return BIT_ONES_DEC movf adrs_LW,w movwf 21h decf 21h,1 movlw 0x0F andwf 21h,1 movlw 0xF0 andwf adrs_LW,1 movf 21h,w addwf adrs_LW,1 movwf 21h call HEXA_TO_LCD_WAIT return ;********************************* Address edit bits - Increment BIT_HUNDREDS_INC incf adrs_HI,1 movlw 0x0F andwf adrs_HI,1 movlw 0x0F andwf adrs_HI,w movwf 21h call HEXA_TO_LCD_WAIT return BIT_TENS_INC movlw 0x10 addwf adrs_LW,1 movlw 0xF0 andwf adrs_LW,w movwf 21h swapf 21h,1 call HEXA_TO_LCD_WAIT return BIT_ONES_INC movf adrs_LW,w movwf 21h incf 21h,1 movlw 0x0F andwf 21h,1 movlw 0xF0 andwf adrs_LW,1 movf 21h,w addwf adrs_LW,1 movwf 21h call HEXA_TO_LCD_WAIT return ;***************************** HEXA_TO_LCD_WAIT call HEXA_TO_LCD goto Wait ;********************************* cursor moves OK_B ; cursor position 6 & 7 edit data, 12-14 edit address incf curPOS,1 movlw d'15' subwf curPOS,w btfsc STATUS,Z call INI_POS_DT ; roll back to data edit position movlw d'8' subwf curPOS,w btfsc STATUS,Z call INI_POS_ADRS ; jump to address edit position goto Wait return INI_POS_DT movlw d'6' movwf curPOS return INI_POS_ADRS movlw d'12' movwf curPOS return ;********************************* no response for a long press Wait btfss PORTA,0 ; stay here if A0 is still pressed =0 goto Wait btfss PORTA,1 ; stay here if A2 is still pressed =0 goto Wait btfss PORTA,2 goto Wait btfss PORTA,3 goto Wait btfss PORTA,4 goto Wait movlw 0x0F ; display ON, cursor blink call writeCMD movlw LINE2 addwf curPOS,w call POS_LCD movlw 10 movwf del call delay goto A_INC ;********************************* increment decrement address by 1 INC call DATA_CHNG ; if data changed movlw 0xFF subwf adrs_LW,w btfsc STATUS,Z incf adrs_HI,1 ; if adrs_LW is equal FF incf adrs_LW,1 call READ_EEPROM return DEC movlw 0x00 subwf adrs_LW,w btfsc STATUS,Z decf adrs_HI,1 ; if adrs_LW is equal 00 decf adrs_LW,1 call READ_EEPROM return DATA_CHNG movf 20h,w ; check if data bits are changed subwf bitDATA,w btfss STATUS,Z call WRITE_EEPROM return ;****************************************************************************************** WRITE_EEPROM call START_DEF_EEPROM ; start definition call DEVICE_ADDRESS bcf PORTB,7 ; 0 write call CLK_EE ; clock call CLK_EE ; clock, ACK movf adrs_HI,w ; 1st word address call WORD_ADDRESS ; movf adrs_LW,w ; 2nd word address call WORD_ADDRESS ; movf bitDATA,w call WORD_ADDRESS ; send data call STOP_DEF_EEPROM ; stop definition return ;****************************************************************************************** READ_EEPROM movlw LINE1+d'11' ; write character to 1st line LCD call POS_LCD call MS1 ; 'addr' label movlw LINE1+0 ; write received Binary data to first line LCD call POS_LCD call START_DEF_EEPROM ; start definition call DEVICE_ADDRESS bcf PORTB,7 ; 0 write call CLK_EE ; clock call CLK_EE ; clock, ACK movf adrs_HI,w ; 1st word address call WORD_ADDRESS ; movf adrs_LW,w ; 2nd word address call WORD_ADDRESS ; call START_DEF_EEPROM ; start definition call DEVICE_ADDRESS bsf PORTB,7 ; 1 read call CLK_EE ; clock call PORT_B7_IN ; switch RB7 to input call CLK_EE ; clock, ACK call RCV_DT ; receive data from EEPROM call PORT_B7_OUT ; switch RB7 to output bcf PORTB,7 ; call CLK_EE ; clock, ACK movlw LINE2+0 ; write character to 2nd line LCD call POS_LCD movf 20h,w call writeDATA ; TO_LCD movf 20h,w ; save data for edit movwf bitDATA movlw LINE2+6 ; write HI-bit hex code data to 2nd line LCD call POS_LCD movlw 0xF0 andwf 20h,w movwf 21h swapf 21h,1 call HEXA_TO_LCD movlw LINE2+7 ; write LOW-bit hex code data to 2nd line LCD call POS_LCD movlw 0x0F andwf 20h,w movwf 21h call HEXA_TO_LCD movlw LINE2+d'14' ; write character to 1st line LCD call POS_LCD movlw b'00001111' andwf adrs_LW,w movwf 21h call HEXA_TO_LCD movlw LINE2+d'13' ; write character to 1st line LCD call POS_LCD swapf adrs_LW,w movwf 21h movlw b'00001111' andwf 21h,1 call HEXA_TO_LCD movlw LINE2+d'12' ; Hundreds digit Hexadecimal call POS_LCD movlw b'00001111' andwf adrs_HI,w movwf 21h call HEXA_TO_LCD movlw LINE2+curPOS ; put back the cursor to the last position the user left it call POS_LCD goto Wait ;****************************************************************************************** HEXA_TO_LCD call HEXA call TO_LCD return HEXA movlw b'1010' subwf 21h,w ; sub if greater than 9 btfsc STATUS,C ; call HEX_A_LCD ; ?>9 add alphanumeric (A-F) movf 21h,w return HEX_A_LCD movlw d'7' ; for LCD from A-F addwf 21h,1 return ;**************************** PORT_B7_IN bsf STATUS,RP0 ; Switch to Bank 1 movlw b'10000000' ; Set the Port B pins RB7 to input movwf TRISB bcf STATUS, RP0 return PORT_B7_OUT bsf STATUS,RP0 ; Switch to Bank 1 movlw b'00000000' ; Set the Port B pins RB7 to input movwf TRISB bcf STATUS, RP0 return ;****************** RCV_DT movlw 7 movwf 21h clrf 1fh ; binary data holder clrf 20h ; hex data holder call RD_BIT ; read bit7 call CLK_EE call SHIFT_BIT ; read bit6-0 decfsz 21h,1 btfss STATUS,Z goto $+2 goto $-5 return ;****************** SHIFT_BIT BCF STATUS,C RLF 20h,1 BCF STATUS,C RD_BIT movlw 0 btfsc PORTB,7 ; read RB7, if 0 skip next line movlw 1 movwf 1fh addwf 20h,1 ; store data movf 1fh,w addlw 0x30 ; convert Binary for LCD call writeDATA ; TO_LCD return ;****************** START_DEF_EEPROM bsf PORTB,7 ; set RB7 bsf PORTB,6 ; set RB6 bcf PORTB,7 ; 0 RB7 bcf PORTB,6 ; 0 RB6 return ;****************** STOP_DEF_EEPROM bsf PORTB,6 ; set RB6 bsf PORTB,7 ; set RB7 ;bcf PORTB,6 ; 0 RB6 ;bcf PORTB,7 ; 0 RB7 return ;****************** DEVICE_ADDRESS bsf PORTB,7 ; MSB call CLK_EE ; clock bcf PORTB,7 ; 0 call CLK_EE ; clock bsf PORTB,7 ; 1 call CLK_EE ; clock bcf PORTB,7 ; 0 call CLK_EE ; clock call CLK_EE ; clock, device address A2, (0 for A2-A0, communication with one eeprom only) call CLK_EE ; clock, device address A1 call CLK_EE ; clock, device address A0 return ;****************** WORD_ADDRESS BCF STATUS,C movwf 1fh ; put word address to register movlw 8 ; word length movwf 1eh SWA call SHIFT_WORD_ADDRESS call CLK_EE ; clock,word address decf 1eh,1 ; decrement 1eh counter by 1, result to 1eh btfsc STATUS,Z ; jump next line when Z set to 1 goto JMP_1 ; when Z=0 jump out goto SWA ; read next word address bit JMP_1 call PORT_B7_IN call CLK_EE ; clock, ACK call PORT_B7_OUT return SHIFT_WORD_ADDRESS rlf 1fh,1 bcf PORTB,7 btfsc STATUS,C bsf PORTB,7 return ;****************** CLK_EE bsf PORTB,6 ; set RB6 bcf PORTB,6 ; 0 RB6 return ;****************************************************************************************** TO_LCD addlw 0x30 call writeDATA movlw LINE2+curPOS ; call POS_LCD return POS_LCD call writeCMD movlw 30 movwf del call delay return ;*********************************************************************************************** ; procedures initLCD ; initialize LCD right after power up movlw 30 movwf del call delay ; a 15 msec delay after power is on movlw 3 movwf PORTB ; start LCD init process movlw 10 movwf del call delay ; wait for 5 msec movlw 3 movwf PORTB ; start LCD init process bsf PORTB, 4 ; toggle the LCD Enable pin bcf PORTB, 4 movlw 10 movwf del call delay ; wait for 5 msec bsf PORTB, 4 ; repeat the reset command (2nd time) bcf PORTB, 4 movlw 80 ; wait for 200 usec sublw 1 sublw 0 btfss STATUS, Z goto $-3 bsf PORTB, 4 ; repeat the reset command (3rd time) bcf PORTB, 4 movlw 80 ; wait for 200 usec sublw 1 sublw 0 btfss STATUS, Z goto $-3 movlw 2 ; initialize LCD 4-bit mode movwf PORTB bsf PORTB, 4 ; toggle the LCD Enable pin bcf PORTB, 4 movlw 10 movwf del call delay movlw 0x28 ; LCD 4-bit mode, 2-line mode, char font 5x7 call writeCMD movlw 1 call writeCMD ; clear and home display movlw 10 ; wait for 5 msec after clearing movwf del call delay movlw 0x06 ; cursor move after each char right call writeCMD movlw 0x0F ; turn on LCD and enable cursor, blinking call writeCMD return writeCMD ; write to LCD a 1-byte command in W movwf temp swapf temp, w andlw 0x0F ; leave only the high 4 bits in W movwf PORTB bsf PORTB, 4 ; toggle the E bit bcf PORTB, 4 movfw temp ; proceed with the low bit andlw 0x0F movwf PORTB bsf PORTB, 4 ; toggle the bit bcf PORTB, 4 movlw 80 ; wait for 200 usec sublw 1 sublw 0 btfss STATUS, Z goto $-3 return writeDATA ; write to LCD a 1-byte data in W movwf temp swapf temp, w andlw 0x0F ; leave only the lower 4 bits in W movwf PORTB bsf PORTB, 5 ; sending data bsf PORTB, 4 ; toggle the E bit bcf PORTB, 4 movfw temp ; proceed with the low bit andlw 0x0F movwf PORTB bsf PORTB, 5 ; sending data bsf PORTB, 4 ; toggle the bit bcf PORTB, 4 movlw 10 ; wait for 5 msec movwf del call delay return delay ; a delay for del milliseconds movlw d'200' sublw 1 ; this loop takes 5us*200 = 1ms sublw 0 ; for PIC16F84A @ 4 Mhz btfss STATUS, Z goto $-3 decfsz del,f goto delay return end