;******************************************************************** ; W A T T M E T E R ;******************************************************************** ; Bruce Abbott bhabbott@paradise.net.nz ; ; - Measures up to 25 Volts and 50 Amps ; - Displayed on 16x1 LCD ; - Calculates Watts and Amp hours ; - Hold function. ; ; processor PIC16f870 ; processor PIC16F88 ifdef __16F870 include P16f870.inc #DEFINE TMR0IF T0IF else include P16F88.inc endif radix dec ; default number format is DECIMAL!!! errorlevel -302,-305 ; not reporting bank<>0, dest=file #DEFINE FALSE 0 #DEFINE movfw ERROR movwf? ; away with thee, abomination! ifdef __16F870 __config _BODEN_OFF&_WDT_OFF&_LVP_OFF&_PWRTE_ON&_HS_OSC else ; 16F88 __config _CONFIG1,_BODEN_OFF&_WDT_OFF&_LVP_OFF&_MCLR_OFF&_PWRTE_ON&_INTRC_IO endif #DEFINE REFRESH_DELAY 39 ; I/O pin assignments ifdef __16F870 #DEFINE PGBTN PORTC,0 ; page button (PORTC) #DEFINE HDBTN PORTC,1 ; hold button (PORTC) #DEFINE LCD_D7 PORTB,0 #DEFINE LCD_D6 PORTB,1 #DEFINE LCD_D5 PORTB,2 ; LCD panel (PortB) #DEFINE LCD_D4 PORTB,3 #DEFINE LCD_E PORTB,4 #DEFINE LCD_RS PORTB,5 else ; 16f88 #DEFINE PGBTN PORTB,6 ; page button (PORTB) #DEFINE HDBTN PORTB,7 ; hold button (PORTB) #DEFINE LCD_D7 PORTB,0 #DEFINE LCD_D6 PORTB,1 #DEFINE LCD_D5 PORTB,2 ; LCD panel (PortB) #DEFINE LCD_D4 PORTB,3 #DEFINE LCD_RS PORTB,5 #DEFINE LCD_E PORTB,4 endif ;==================================================================== ; Macros to create variables in RAM ; ByteAddr SET 32 ; user RAM starts here BYTE MACRO ByteName ByteName EQU ByteAddr ByteAddr SET ByteAddr+1 ENDM WORD MACRO WordName WordName EQU ByteAddr ByteAddr SET ByteAddr+2 ENDM LONG MACRO LongName LongName EQU ByteAddr ByteAddr SET ByteAddr+4 ENDM ;==================================================================== ; 16 bit macros (Big-Endian) ; mov16 MACRO src,dst movf src,w movwf dst movf src+1,w movwf dst+1 ENDM movi16 MACRO dst,lit movlw HIGH(lit) movwf dst movlw LOW(lit) movwf dst+1 ENDM clr16 MACRO dst clrf dst clrf dst+1 ENDM inc16 MACRO dst incf dst+1 skpnz incf dst ENDM dec16 MACRO dst decf dst+1 skpnz decf dst ENDM add16 MACRO src,dst movf src+1,w addwf dst+1 skpnc incf dst movf src,w addwf dst ENDM addi16 MACRO dst,lit movf LOW(lit),w addwf dst+1 skpnc incf dst movf HIGH(lit),w addwf dst ENDM sub16 MACRO src,dst movf src+1,w subwf dst+1 movf src,w skpc incf src,w subwf dst ENDM subi16 MACRO dst,lit movlw LOW(lit) subwf dst+1 movlw HIGH(lit) skpc movlw (HIGH(lit))+1 subwf dst ENDM lsr16 MACRO dst rrf aa rrf aa+1 ENDM lsl16 MACRO dst rlf aa+1 rlf aa ENDM com16 MACRO dst comf dst+1 comf dst ENDM ;--------------------------------------------------- ; 32 bit macros clr32 MACRO dst clrf dst clrf dst+1 clrf dst+2 clrf dst+3 ENDM mov32 MACRO src,dst movf src,w movwf dst movf src+1,w movwf dst+1 movf src+2,w movwf dst+2 movf src+3,w movwf dst+3 ENDM ; 32 bit left shift rr32 MACRO dst rrf aa rrf aa+1 rrf aa+2 rrf aa+3 ENDM ; 32 bit right shift rl32 MACRO dst rlf aa+3 rlf aa+2 rlf aa+1 rlf aa ENDM com32 MACRO dst comf dst+3 comf dst+2 comf dst+1 comf dst ENDM ; add 16 bit to 32 bit add32 MACRO src,dst ; src(15:0), dst(31:0) movf src+1,w addwf dst+3 ; dst = dst + src(7:0) skpc goto $+6 incf dst+2 skpnz incf dst+1 skpnz incf dst movf src,w addwf dst+2 ; dst = dst + src (15:8) skpc goto $+4 incf dst+1 skpnz incf dst ENDM ;==================================================================== ; Five digit decimal number BYTE TenT BYTE Thou BYTE Hund BYTE Tens BYTE Ones BYTE dp ; position of decimal point ; 16 bit binary number WORD Number ; 16 bit register 'a' WORD aa ; 16 bit register 'b' WORD bb ; 16 bit register 'c' WORD cc ; 32 bit register 'dd' LONG dd ; Volts WORD Volts ; Volts*100 (0.01V resolution) ; Amps WORD Amps ; Amps*100 (0.01A resolution) ; Watts WORD Watts ; Watts*10 (0.1W resolution) ; Amps Accumulated LONG AmpSum ; addition of all Amp readings ; AmpereHours WORD AmpHours ; Amps * Hours ; rpm period WORD Period ; time between blade detections ; rpm WORD rpm ; revolutions per minute ; CCP1 overflows BYTE Overflows ; Zero Amps WORD ZeroAmps ; Number of Readings to Average BYTE Readings ; pointer to character in message string BYTE msg_pointer ; display paging BYTE pagenum ; display refresh timer BYTE ref_timer ; misc variables BYTE Temp BYTE Temp1 BYTE Temp2 ; boolean flags BYTE Flags #DEFINE GOT_ZERO 0 ; Amps zero'd #DEFINE NEG_AMPS 1 ; Amps < zero #DEFINE MAX_VOLTS 2 ; Volts >= max #DEFINE MAX_AMPS 3 ; Amps >= max #DEFINE NEW_PAGE 4 ; Page button pressed #DEFINE LEAD_ZERO 5 ; leading zeros blanked ; reset vector ;//////////////////////////////////////////////////////////////////// ORG 0 goto Start ; interrupt vector ;//////////////////////////////////////////////////////////////////// ORG 4 goto Interrupt ;//////////////////////////////////////////////////////////////////// ORG 8 dt "WOTMTR" ifdef __16F870 dt "70" else dt "88" endif dt "--V0.8--" ;-------------------------------------------------------------------- ; get message characters ; ; Input: W = address of character in message ; Output: W = character ; ; NOTE: Table read:- Must NOT traverse a program page boundary! ; get_message: movwf PCL signon_msg: RETLW 'W' RETLW 'O' RETLW 'T' RETLW ' ' RETLW 'M' RETLW 'e' RETLW 't' RETLW 'e' RETLW 'r' RETLW ' ' RETLW 'V' RETLW '0' RETLW '.' RETLW '0' RETLW '8' RETLW ' ' RETLW 0 ;-------------------------------------------------------------------- ; Interrupt Handler ; WorkSave = 0x7f StatSave = 0x7e Interrupt: movwf WorkSave swapf STATUS,w movwf StatSave clrf STATUS btfss PIR1,CCP1IF goto TMR1_Int CCP1_Int: bcf PIR1,CCP1IF movf CCPR1L,w addwf Period+1 skpnc incf Period movf CCPR1H,w addwf Period skpnc incf Period clrf Overflows TMR1_Int: btfss PIR1,TMR1IF goto Int_done clrf Period clrf Period+1 Int_done: swapf StatSave,W movwf STATUS swapf WorkSave,F swapf WorkSave,w RETFIE ;-------------------------------------------------------------------- ; LCD Display Driver include lcd.asm ;-------------------------------------------------------------------- ; Display Sign-on Message on LCD ; show_signon: movlw 0 call Set_Cursor movlw signon_msg ; ; Display Text Message on LCD ; show_message: movwf msg_pointer call get_message ; get next char in message andlw 0xFF ; end of message ? skpnz return call Print_Char ; show character movlw LCDLENGTH subwf lcd_address,w ; if end of 1st line skpz ; then skip to 2nd line goto show_msg movlw LCDLINE2 call Set_Cursor show_msg: movf msg_pointer,W addlw 1 ; next character goto show_message ;-------------------------------------------------------------------- ; 16x16 bit Multiply (32 bit result) ; ; dd = aa * bb ; ; Input: multiplier = aa(15:0), multiplicand = bb(15:0) ; ; Output: result = dd(32:0) ; ; Uses: aa, w ; Mult16: clrf dd clrf dd+1 clrf dd+2 movlw 0x80 movwf dd+3 m16_next: rrf aa,f rrf aa+1,f skpc goto m16_nobit_l movf bb+1,w addwf dd+2,f movf bb, w skpnc incfsz bb, w addwf dd+1, f skpnc incf dd, f clrc m16_nobit_l: btfss aa+1, 7 goto m16_nobit_h movf bb+1,w addwf dd+1,f movf bb, w skpnc incfsz bb, w addwf dd, f m16_nobit_h: rrf dd,f rrf dd+1,f rrf dd+2,f rrf dd+3,f skpc goto m16_next return ;-------------------------------------------------------------------- ; 32 x 16 bit integer divide ; ; dd = dd / aa ; ; Input: dividend = dd(31:0), divisor = aa(15:0) ; ; Output: quotient = dd(31:0), remainder = bb(15:0) ; ; Uses: bb, Temp, w ; Div32: movlw 32 ; 32 bits to divide movwf Temp clrf bb ; Clear remainder clrf bb+1 div32_loop: clrc ; Set quotient bit to 0 rlf dd+3 rlf dd+2 rlf dd+1 ; Shift dividend left into quotient rlf dd rlf bb+1 rlf bb skpnc ; Check for overflow goto div32_sd movf aa,w ; Compare partial remainder and divisor subwf bb,w skpz ; High Bytes equal? goto div32_gt movf aa+1,w ; Yes, compare Low Bytes subwf bb+1,w div32_gt: skpc ; Carry set if remainder >= divisor goto dvi32_lt div32_sd: movf aa+1,w ; Subtract divisor from partial remainder subwf bb+1 skpc ; Test for borrow decf bb ; Subtract borrow movf aa,w subwf bb bsf dd+3,0 ; Set quotient bit (quotient replaces dividend) dvi32_lt: decfsz Temp ; next bit goto div32_loop return ;-------------------------------------------------------------------- ; 16 bit Integer Divide by 12.8 ; ; Input: W->dst ; ; output: dst(15:0) = dst / 12.8 ; ; uses: FSR, Temp, w ; ; ; ALGORITHM: ; Add dst / 4 to dst ; Add dst / 16 to dst ; Shift dst right (Bit0 to carry) ; If carry set then increment dst, ie. round up Divx12: movwf FSR movf INDF, w movwf Temp incf FSR movf INDF, w decf FSR ;shift dst right twice clrc rrf INDF, f incf FSR rrf INDF, f decf FSR clrc rrf INDF, f incf FSR rrf INDF, f ;add dst to dst / 4 addwf INDF, f decf FSR movf Temp, w skpnc incfsz Temp, w addwf INDF, f ;shift dst right 3 times rrf INDF, f incf FSR rrf INDF, f decf FSR clrc rrf INDF, f incf FSR rrf INDF, f decf FSR clrc rrf INDF, f incf FSR rrf INDF, f decf FSR ;shift dst right once and increment if carry set clrc rrf INDF, f incf FSR rrf INDF, f skpc goto divx12_done incf INDF, f skpz goto divx12_done decf FSR incf INDF, f divx12_done: return ;-------------------------------------------------------------------- ; 16 bit Binary to Decimal ; ; Input: Number(15:0) ; ; Output: TenT, Thou, Hund, Tens, Ones ; ; Uses: Number, w ; ; bin2dec: clrf TenT goto $+2 sub10k: incf TenT movlw 10000&255 subwf Number+1 movlw 10000>>8 skpc movlw (10000>>8)+1 subwf Number skpnc goto sub10k movlw 10 movwf Thou add1k: decf Thou movlw 1000&255 addwf Number+1 movlw 1000>>8 skpnc movlw (1000>>8)+1 addwf Number skpc goto add1k clrf Hund movlw 100 goto $+2 sub100: incf Hund subwf Number+1 skpnc goto sub100 decf Number btfss Number,7 goto sub100 movlw 10 movwf Tens add10: decf Tens addwf Number+1 skpc goto add10 movf Number+1,w movwf Ones return ;-------------------------------------------------------------------- ; Display 5 digit Fixed-point Decimal on LCD ; ; - leading zero blanked ; - 1 digit after decimal point ; ; "9999.9" ; " 999.9" ; " 99.9" ; " 0.0" ; ShowDec1: bsf Flags,LEAD_ZERO movf TenT,w ; leading 0 ? skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' ; convert to ASCII '0'~'9' addlw ' ' call Print_Char ; show Ten Thousands or ' ' movf Thou,w skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' addlw ' ' call Print_Char ; show Thousands or ' ' movf Hund,w skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' addlw ' ' call Print_Char ; show Hundreds or ' ' movf Tens,w addlw '0' call Print_Char ; show Tens movlw '.' call Print_Char ; show '.' movf Ones,w addlw '0' call Print_Char ; show Ones RETURN ;-------------------------------------------------------------------- ; Display 4 digit Fixed-point Decimal on LCD ; ; - leading zero blanked ; - 2 digits after decimal point ; ; "99.99" ; " 9.99" ; " 0.00" ; ShowDec2: movf Thou,w skpz ; leading zero ? addlw '0'-' ' ; convert to ASCII '0'~'9' addlw ' ' call Print_Char ; show thousands or ' ' movf Hund,w addlw '0' call Print_Char ; show hundreds movlw '.' call Print_Char ; show '.' movf Tens,w addlw '0' call Print_Char ; show tens movf Ones,w addlw '0' call Print_Char ; show ones RETURN ;-------------------------------------------------------------------- ; Display 5 digit Decimal on LCD ; ; - leading zero blanked ; ; "65535" ; " 9999" ; " 99" ; " 0" ; ShowDec: bsf Flags,LEAD_ZERO movf TenT,w skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' addlw ' ' call Print_Char ; show ten thousands or ' ' movf Thou,w skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' addlw ' ' call Print_Char ; show thousands or ' ' movf Hund,w skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' addlw ' ' call Print_Char ; show hundreds or ' ' movf Tens,w skpz bcf Flags,LEAD_ZERO btfss Flags,LEAD_ZERO addlw '0'-' ' addlw ' ' call Print_Char ; show tens or ' ' movf Ones,w addlw '0' call Print_Char ; show ones RETURN ;-------------------------------------------------------------------- ; Wait W * 20mS ; waitx20k: movwf Temp _waitx20k: movlw 80 call waitx250 ; wait W*250uS decfsz Temp,F goto _waitx20k RETURN ;-------------------------------------------------------------------- ; Display rpm on LCD ; Show_rpm: movf rpm,w movwf Number movf rpm+1,w movwf Number+1 movlw ' ' call Print_Char call ShowDec ; display "xxxxx" movlw 'r' call Print_Char movlw 'p' call Print_Char movlw 'm' call Print_Char movlw ' ' call Print_Char return ;-------------------------------------------------------------------- ; Display Watts on LCD ; Show_Watts: mov16 Watts,Number call bin2dec call ShowDec1 ; display "xxxx.x" movlw 'W' call Print_Char ; display 'W' movlw ' ' call Print_Char return ;-------------------------------------------------------------------- ; Display Volts on LCD ; Show_Volts: mov16 Volts,Number call bin2dec movlw 0 call Set_Cursor call Print_Char movlw ' ' call ShowDec2 ; display "xx.xx" movlw 'V' call Print_Char movlw ' ' btfsc Flags,MAX_AMPS movlw '+' ; display '+' if overflow call Print_Char return ;-------------------------------------------------------------------- ; Display Amps on LCD ; Show_Amps: mov16 Amps,Number movlw ' ' btfsc Flags,NEG_AMPS movlw '-' ; display '-' if negative call Print_Char call bin2dec call ShowDec2 ; display "xx.xx" movlw 'A' call Print_Char movlw ' ' btfsc Flags,MAX_AMPS movlw '+' ; display '+' if overflow call Print_Char return ;-------------------------------------------------------------------- ; Display Amperes * Hours on LCD ; Show_AmpHours: mov16 AmpHours,Number call bin2dec movlw ' ' call Print_Char call ShowDec2 ; display "xx.xx" movlw 'A' call Print_Char movlw 'h' call Print_Char return ;-------------------------------------------------------------------- ; Main Program Starts Here! ; Start: clrf PORTA clrf PORTB bsf STATUS,RP0 ; bank 1 movlw B'11111111' ; PortA directions movwf TRISA movlw B'00000000' ; PortB directions movwf TRISB ifdef __16F870 movlw B'11111111' ; PortC directions movwf TRISC endif ifdef __16F88 movlw B'01100000' ; 4MHz internal osc (16F88) movwf OSCCON endif movlw B'11010111' ; Timer0 source = clkout/256 movwf OPTION_REG bcf STATUS,RP0 ; bank 0 ; Set up Interrupts ; bsf INTCON,PEIE ; enable peripheral ints ; bsf INTCON,GIE ; enable interrupts ; set up LCD Display movlw 25 ; wait 500mS call waitx20k call LCDinit ; Set up the LCD display call show_signon ; show signon message movlw 25 ; wait 500mS call waitx20k ; set up A/D convertor bsf STATUS,RP0 ; bank 1 movlw b'10001101' ; right-justify, ext ref, inputs RA1/RA0 movwf ADCON1 ; bsf PIE1,ADIE ; enable A/D interrupts bcf STATUS,RP0 ; bank 0 ; Start Timer0 movlw REFRESH_DELAY movwf TMR0 bcf INTCON,TMR0IF ; initialize variables clrf Flags clrf pagenum clr32 AmpSum ReadInputs: movlw 15 ; wait 3mS call waitx250 clrf Volts clrf Volts+1 clrf Amps clrf Amps+1 clrf Watts clrf Watts+1 movlw 64 ; 64 * 10 bit readings movwf Readings ; (16 bit results) NextRead: movlw b'01000001' ; CLK/8, select RA0 (Volts) movwf ADCON0 call wait100 ; wait 100uS to stabilize analog input bsf ADCON0,2 ; start A/D conversion waitv: btfsc ADCON0,2 goto waitv ; wait until conversion Done movf ADRESH,w movwf Temp1 addwf Volts bsf STATUS,RP0 movf ADRESL,w ; add 10 bit A/D result to Volts bcf STATUS,RP0 movwf Temp2 addwf Volts+1 skpnc incf Volts bcf Flags,MAX_VOLTS movf Temp1,w xorlw b'00000011' skpnz bsf Flags,MAX_VOLTS ; Volts overloaded ? movf Temp2,w xorlw b'11111111' skpz bcf Flags,MAX_VOLTS movlw b'01001001' ; CLK/8, select RA1 (Amps) movwf ADCON0 call wait100 ; wait 100uS to stabilize analog input bsf ADCON0,2 ; start A/D conversion waita: btfsc ADCON0,2 goto waita ; wait until conversion Done movf ADRESH,w movwf Temp1 addwf Amps bsf STATUS,RP0 movf ADRESL,w ; get 10 bit A/D result bcf STATUS,RP0 movwf Temp2 addwf Amps+1 skpnc incf Amps bcf Flags,MAX_AMPS movf Temp1,w xorlw b'00000011' skpnz bsf Flags,MAX_AMPS ; Amps overloaded ? movf Temp2,w xorlw b'11111111' skpz bcf Flags,MAX_AMPS decfsz Readings goto NextRead ; accumulate readings clrc rrf Volts ; Volts / 2 rrf Volts+1 movlw Volts call Divx12 ; Volts / 12.8 movlw Amps call Divx12 ; Amps / 12.8 btfsc Flags,GOT_ZERO ; have Amps been zeroed ? goto sub_zero get_zero: movf Amps,w movwf ZeroAmps ; record zero Amps value movf Amps+1,w movwf ZeroAmps+1 bsf Flags,GOT_ZERO sub_zero: bcf Flags,NEG_AMPS sub16 ZeroAmps,Amps ; subtract zero value from Amps skpnc goto got_amps bsf Flags,NEG_AMPS com16 Amps ; Amps = -0 to -0.99 got_amps: mov16 Amps,aa mov16 Volts,bb call Mult16 ; Watts = Volts * Amps movi16 aa,1000 call Div32 ; Watts = Watts / 1000 subi16 bb,500 skpc ; remainder > 0.5 ? goto store_watts inc16 dd+2 ; yes, round up store_watts: mov16 dd+2,Watts add32 Amps,AmpSum ; AmpSum = accumulated Amps mov32 AmpSum,dd movi16 aa,3600*3 ; 3 reads per second, 3600 seconds per hour call Div32 ; AmpHours = AmpSum / (reads per hour) store_amphrs: mov16 dd+2,AmpHours ; show results on LCD screen do_display: movlw 6 ; to repeat every 333.3mS movwf ref_timer btfsc PGBTN ; page button pressed ? goto newline ; no nextpage: incf pagenum ; yes, page+1 movlw 3 subwf pagenum,w skpnc ; page=0~2 clrf pagenum bsf Flags,NEW_PAGE newline: movlw 0 call Set_Cursor ; set cursor to start of line movf pagenum,w addlw -1 skpc ; page=0 ? goto page0 skpnz ; page=1 ? goto page1 ; page=2 page2: call Show_Volts movlw LCDLINE2 call Set_Cursor ; "99.99V 99.99Ah" call Show_AmpHours goto pagedone page1: call Show_Watts movlw LCDLINE2 call Set_Cursor ; "999.9W 99.99A" call Show_Amps goto pagedone page0: call Show_Volts movlw LCDLINE2 call Set_Cursor ; "99.99V 99.99A" call Show_Amps pagedone: btfss Flags,NEW_PAGE ; was page button on ? goto checkhold ; no waitpageoff: btfss PGBTN ; wait for page button off goto waitpageoff bcf Flags,NEW_PAGE movlw 10 ; debounce 200mS call waitx20k checkhold: btfsc HDBTN ; hold button on ? goto hold_off ; no btfss PGBTN ; page button pressed ? goto nextpage ; yes, show next page goto checkhold ; no, wait until hold button off hold_off: btfss INTCON,TMR0IF goto checkhold ; wait 55.555mS movlw REFRESH_DELAY addwf TMR0 bcf INTCON,TMR0IF decfsz ref_timer ; wait 55.555 * 6 = 333.3mS goto checkhold goto ReadInputs END