; WRITTEN BY G.C.Hartnup ; Copyright Reserved G.C.Hartnup ; DATE July 5 2020 ;*********************** ;****CURRENT VERSION**** issue 1.0 5/7/20 ;*********************** ; ; FILE SAVED AS NCAD.ASM ; FOR PIC 16F818 list p=16F818 errorlevel -302 ;omit memory bank warning messages ; 8.00 MHz Internal Clock ; INSTRUCTION CLOCK 2.00 MHz, Tick = 0.5uS ; ; FUNCTION DCC Accessory decoder ; 4 servo channels ; Page address set on Hex Switch ; Servo Limits set by Potentiometer ; Library Files include "P16F818.inc" ;------------------------ ;--- Set Configuration--- ;------------------------ ; Code protection off ; Watchdog timer on ; PWRTE Power Restart enable ; Internal Oscillator ; Master Clear OFF (Makes Pin 3 available, MCLR tied to Vdd) __CONFIG _CP_OFF & _PWRTE_ON & _INTRC_IO & _WDT_ON & _MCLRE_ON ; ;----------- ;---Ports--- ;----------- ; ;logic level dcc input #define _in PORTA,RA4 ;dcc in ;calibration mode #define _ANIN PORTA,AN0 ;analogue in from Pot #define _save PORTB,RB4 ;save data #define _hilo PORTB,RB6 ;hi/lo value #define _kal PORTB,RB5 ;set calibration mode ;servo outputs #define _servo1 PORTA,RA2 ;servo 1 output #define _servo2 PORTA,RA1 ;servo 2 output #define _servo3 PORTA,RA7 ;servo 3 output #define _servo4 PORTA,RA6 ;servo 4 output ;hex dil switch #define _ad1 PORTB,RB0 ;page address bit 0 from hex switch #define _ad2 PORTB,RB2 ;page address bit 2 #define _ad4 PORTB,RB3 ;page address bit 4 #define _ad8 PORTB,RB1 ;page address bit 8 ;acknowledge led #define _led PORTB,RB7 ;signal led ;---------- ;---data--- ;---------- _trisA equ 0x11 ;RA0 and RA4 as i/p _trisB equ 0x7f ; port RB7 as o/p. rest as i/p _adcon1 equ 0x8e ;A/D settings _adcon0 equ 0x41 s1 equ 2 ;servo o/p bits s2 equ 1 s3 equ 7 s4 equ 6 ; ; ;--------------- ;---Variables--- ;--------------- CC equ 0x2c ;micellaneous use DD equ 0x2d EE equ 0x2e FF equ 0x2f cnt equ 0x30 ;bit counter cnt2 equ 0x31 ;pulse counter address equ 0x32 ;received address _data equ 0x33 ;received data byte equ 0x34 ;value returned by getbyte instr equ 0x35 ;received instruction errb equ 0x36 ;received error byte _temp equ 0x37 ;temporary storage oldch1 equ 0x38 ;old servo states oldch2 equ 0x39 oldch3 equ 0x3a oldch4 equ 0x3b uhi equ 0x3c ;pulse length hi byte ulo equ 0x3d ;pulse length lo byte ; minlo1 equ 0x3e ;negated servo pulse lengths minhi1 equ 0x3f ;servo 1 maxlo1 equ 0x40 maxhi1 equ 0x41 ; minlo2 equ 0x42 ;negated servo pulse lengths minhi2 equ 0x43 ;servo 2 maxlo2 equ 0x44 maxhi2 equ 0x45 ; minlo3 equ 0x46 ;negated servo pulse lengths minhi3 equ 0x47 ;servo 3 maxlo3 equ 0x48 maxhi3 equ 0x49 ; minlo4 equ 0x4a ;negated servo pulse lengths minhi4 equ 0x4b ;servo 4 maxlo4 equ 0x4c maxhi4 equ 0x4d ; v equ 0x4e ;received state myaddr equ 0x4f ;decoder page address mask equ 0x50 ;mask for servo drive ;---------- ;---data--- ;---------- blo equ 0xdf ;frame pulse length bhi equ 0xb1 ; bg org 0 ;start or reset vector BANKSEL PORTA goto init st org 4 ;interrupt vector retfie ;return, in case one happens ;----------------- ;---subroutines--- ;----------------- ;EERAM ;----------------- ;---Write EERAM--- ;----------------- ; on entry CC contains EEram address, DD contains data WRAM movf CC,w BANKSEL EECON1 btfsc EECON1, WR ; Wait for write goto $-1 ; to complete BANKSEL EEADR ; Select Bank of EEADR movf CC, W movwf EEADR movf DD, W movwf EEDATA BANKSEL EECON1 bcf EECON1, EEPGD ; Point to DATA bsf EECON1, WREN bcf INTCON, GIE movlw 0x55 movwf EECON2 movlw 0xAA movwf EECON2 bsf EECON1, WR bcf EECON1, WREN btfsc EECON1,WR ;loop until write completed goto $-1 BANKSEL TMR1 return ;---------------- ;---Read EERAM--- ;---------------- ;on entry w contains address, on exit w contains data ; on entry w holds eeram address ; on exit w holds data RRAM BANKSEL EEADR movwf EEADR ; set address BANKSEL EECON1 bcf EECON1,EEPGD ; do a read bsf EECON1,RD BANKSEL EEDATA movf EEDATA,w ; data to w BANKSEL PORTA return ;--------------------- ;---16 bit addition--- ;--------------------- ;CC,DD +EE,FF = CC.DD addit movf EE,w ;2 byte addition routine addwf CC,f btfsc STATUS,0 incf DD,f movf FF,w addwf DD,f skpnc retlw -1 retlw 0 return ;-------------------------------------------- ;---read in device address from hex switch--- ;-------------------------------------------- getmyaddr clrf myaddr btfss _ad1 bsf myaddr,0 btfss _ad2 bsf myaddr,1 btfss _ad4 bsf myaddr,2 btfss _ad8 bsf myaddr,3 return ;---------------------- ;---get pulse length--- ;---------------------- ;measure from low edge to next low edge ;returns 1 or 0 in w ;if timer1 overflows, dcc controller has probably tripped ; _in is the input port getbit clrwdt btfsc _in goto getbit pb1 clrwdt btfss _in ;is it lo? goto pb1 clrf TMR1L ;zero value of timer clrf TMR1H ;clear msb bsf T1CON,TMR1ON ;start timer 1 pb2 clrwdt btfsc _in goto pb2 bcf T1CON,TMR1ON ;stop Timer 1 movf TMR1L,w ;get lo byte movwf CC decf CC,f ;less 1 movf TMR1H,w ;get hi byte movwf DD ;determine if pulse is a one or a zero ;returns 1 or 0 in w bnz d1 ;far too long movlw 0x4d ;less than 77 microseconds subwf CC,w bc d1 ;it is a nought movlw 1 ;it is a one return d1 clrw ;report nought return ;get 8 bits from the data stream, returned in byte getbyte clrwdt clrf byte bcf PIR1,0 ;clear overflow flag movlw 0xf8 movwf cnt ;to count bits gb1 call getbit ;get bit from dcc stream movwf FF rrf FF,f ;bit into C rlf byte,f ;hence into byte incfsz cnt,f ;test for 8 bits goto gb1 return ;---------------------------------- ;---packet spacing for servo o/p--- ;---------------------------------- frame bcf T1CON,0 ;stop timer1 movlw blo ;load frame length movwf TMR1L movlw bhi movwf TMR1H bcf PIR1,0 ;clear tmr1 flag bsf T1CON,0 ;start timer 1 nop btfss PIR1,0 ;check tmr1 flag for end goto $-2 bcf PIR1,0 ;clear tmr1 flag clrwdt ;after each frame spacer return ;---------------------------- ;---generate a servo pulse--- ;---------------------------- ;on entry CC, DD hold pulse length ;bit turned on and off by caller pulse bcf T1CON,0 ;stop timer1 bcf PIR1,0 ;clear timer1 flag movf CC,w movwf TMR1L movf DD,w movwf TMR1H bsf T1CON,0 ;start timer 1 nop btfss PIR1,0 ;check timer1 flag for end goto $-2 return ;----------------------- ;---servo pulse train--- ;----------------------- ;on entry ulo, uhi contains pulse length ;on entry mask contains PORTA bit for servo fcp movlw 0x14 ;twenty pulses only movwf cnt2 movf ulo,w movwf CC movf uhi,w movwf DD fcp1 movf mask,w iorwf PORTA,f ;selected bit high call pulse movlw 0x39 andwf PORTA,f ;all servo bits low call frame decfsz cnt2,f goto fcp1 clrwdt return ;-------------------------------- ;---- RESET & INITIALISATION ---- ;-------------------------------- ;this section configures the PIC init BANKSEL PORTA ; set up Memory Bank 0 btfss STATUS,4 ;was it wdt restart? goto bp ;yes, don't change anything, stop servos resetting clrf PORTA BANKSEL OSCCON movlw 0x60 movwf OSCCON ;select 4MHz clock ;set watchdog and pullups movlw 0x0e movwf OPTION_REG ;set port i/o movlw _trisA movwf TRISA ;PortA I/O movlw _trisB movwf TRISB ;PortB I/O ;inhibit interrupts clrf INTCON ;turn off comparator BANKSEL CCP1CON clrf CCP1CON ;turn off A/D clrf ADCON0 ;configure timer 1 BANKSEL T1CON movlw 0x80 movwf T1CON ; ;----------------------------------- ;---Get Servo Settings from EERAM--- ;----------------------------------- ;servo 1 movlw 0 ;EERAM relative address call RRAM ;read EERAM movwf minlo1 comf minlo1,f ;(rough negate) movlw 1 call RRAM movwf minhi1 comf minhi1,f movlw 2 call RRAM movwf maxlo1 comf maxlo1,f movlw 3 call RRAM movwf maxhi1 comf maxhi1,f ;servo 2 movlw 4 call RRAM movwf minlo2 comf minlo2,f movlw 5 call RRAM movwf minhi2 comf minhi2,f movlw 6 call RRAM movwf maxlo2 comf maxlo2,f movlw 7 call RRAM movwf maxhi2 comf maxhi2,f ;servo 3 movlw 8 call RRAM movwf minlo3 comf minlo3,f movlw 9 call RRAM movwf minhi3 comf minhi3,f movlw 0x0a call RRAM movwf maxlo3 comf maxlo3,f movlw 0x0b call RRAM movwf maxhi3 comf maxhi3,f ;servo 4 movlw 0x0c call RRAM movwf minlo4 comf minlo4,f movlw 0x0d call RRAM movwf minhi4 comf minhi4,f movlw 0x0e call RRAM movwf maxlo4 comf maxlo4,f movlw 0x0f call RRAM movwf maxhi4 comf maxhi4,f ;-------------------------------------------- ;---read in device address from hex switch--- ;-------------------------------------------- call getmyaddr bsf myaddr,7 ;set bit 7 clrwdt ;----------------------- ;---Initialise Servos--- ;----------------------- clrf oldch1 ;set last state to false clrf oldch2 clrf oldch3 clrf oldch4 ;move servos to start position (min) movf minlo1,w ;servo 1 movwf ulo ;set pulse length movf minhi1,w movwf uhi clrf mask bsf mask,s1 call fcp ;generate pulse train movf minlo2,w ;servo2 movwf ulo movf minhi2,w movwf uhi clrf mask bsf mask,s2 call fcp ;generate pulse train movf minlo3,w ;servo 3 movwf ulo movf minhi3,w movwf uhi clrf mask bsf mask,s3 call fcp ;generate pulse train movf minlo4,w ;servo 4 movwf ulo movf minhi4,w movwf uhi clrf mask bsf mask,s4 call fcp ;generate pulse train ;now start up ; ;test for calibrate mode bp bcf _led ;light out btfss _kal goto kal ;switch is "on" so go to calibrate mode ;----------------------- ;---look for Preamble--- ;----------------------- ;look for preamble, >10 successive "1"s ;don't bother about service mode (long preamble) ;as it is not used clrf cnt p1 clrwdt bcf PIR1,0 ;clear overflow flag call getbit ;result returned in w iorlw 0 ;test for "1" bz bp ;it wasn't a "1",start again incf cnt,f ;increment counter movlw 0x0a ;ten subwf cnt,w bnz p1 ;check length of preamble pb16 call getbit incf cnt,f ;increment counter iorlw 0 ;look for end bnz pb16 ;----------------------- ;--- Get Address Byte--- ;----------------------- ;we have already received start bit so get a data byte p2 call getbyte ;now look for a zero in next startbit call getbit iorlw 0 bnz bp ;failed start again movf byte,w movwf address ;get data call getbyte ;result returned in byte ;look for a zero in next startbit call getbit ;returned in w iorlw 0 bnz bp ;failed start again movf byte,w movwf _data ;get error byte and test call getbyte ;result returned in byte ;look for a one in startbit (end of packet) call getbit ;returned in w xorlw 1 ; bnz bp ;failed, don't bother movf byte,w movwf errb ;check page address movf myaddr,w subwf address,w ;compare with device page number bnz bp ;fail, so round again ;process instruction ;we have valid data, so check it out ;we are looking for movlw 7 andwf _data,f ;mask off unwanted bits ;on or off movlw 0x01 btfsc _data,0 clrw movwf v ;LSB contains servo state, "1" or "0" ;now find which channel ;and set ulo, uhi as pulse length rrf _data,f ;lsb into carry movlw 0x03 ;mask 2 lowest bits andwf _data,f ;sub channel address now in _data bz sig1 decf _data,f bz sig2 decf _data,f bz sig3 ;process channel 4 ;check if needed movf oldch4,w subwf v,w bz bp ;not needed movf v,w ;change last setting movwf oldch4 ;set pulse length on whether v is "1" or "0" btfsc v,0 goto sig4b ;v is false movf minlo4,w movwf ulo movf minhi4,w movwf uhi clrf mask bsf mask,s4 call fcp goto bp sig4b movf maxlo4,w movwf ulo movf maxhi4,w movwf uhi clrf mask bsf mask,s4 call fcp ;generate pulse chain goto bp ;process channel 3 sig3 ;check if needed movf oldch3,w subwf v,w bz bp ;not needed movf v,w ;change last setting movwf oldch3 ;set pulse length on whether v is true of false btfsc v,0 goto sig3b ;v is false movf minlo3,w movwf ulo movf minhi3,w movwf uhi clrf mask bsf mask,s3 call fcp goto bp sig3b movf maxlo3,w movwf ulo movf maxhi3,w movwf uhi clrf mask bsf mask,s3 call fcp ;generate pulse chain goto bp ;process channel 2 sig2 ;check if needed movf oldch2,w subwf v,w bz bp ;not needed movf v,w ;change last setting movwf oldch2 ;set pulse length on whether v is true of false btfsc v,0 goto sig2b ;v is false movf minlo2,w movwf ulo movf minhi2,w movwf uhi clrf mask bsf mask,s2 call fcp ;generate pulse chain goto bp sig2b movf maxlo2,w movwf ulo movf maxhi2,w movwf uhi clrf mask bsf mask,s2 call fcp ;generate pulse chain goto bp ;process channel 1 sig1 ;check if needed movf oldch1,w subwf v,w bz bp ;not needed movf v,w ;change last setting movwf oldch1 ;set pulse length on whether v is true of false btfsc v,0 goto sig1b ;v is false movf minlo1,w movwf ulo movf minhi1,w movwf uhi clrf mask bsf mask,s1 call fcp ;generate pulse chain goto bp sig1b movf maxlo1,w movwf ulo movf maxhi1,w movwf uhi clrf mask bsf mask,s1 call fcp ;generate pulse chain goto bp ;--------------------------- ;---Calibrate Servo Throw--- ;--------------------------- kal BANKSEL ADCON1 ;set up a/d movlw _adcon1 movwf ADCON1 BANKSEL ADCON0 movlw _adcon0 movwf ADCON0 ;turn on A/D call frame ;to give a pause to settle A/D kal2 clrwdt bsf _led ;light on to indicate calibration mode call getmyaddr ;renew address in case of change decf myaddr,f ;reduce range to 0 -3 movlw 3 ;mask off all but last 2 bits, value in range 0-3 andwf myaddr,f ;gives servo address bsf ADCON0,2 btfsc ADCON0,2 goto $-1 movf ADRESH,w ;gives value between 0 and 3ffh (1023) movwf DD BANKSEL ADRESL movf ADRESL,w BANKSEL PORTA movwf CC movlw 3 ;add 977 movwf FF movlw 0xD1 movwf EE call addit ;result in DD, CC is rquired pulse length in microseconds comf CC,f ;rough negate, 1 not added to solve carry problem. comf DD,f ;timer 2 increments, so negative value needed ;set o/p bit ;myaddr has a value 0 - 3 movf myaddr,w bnz n1 bsf _servo1 goto n4 n1 rrf myaddr,f bnc n2 bsf _servo2 goto n4 n2 bnz n3 bsf _servo3 goto n4 n3 bsf _servo4 ;set o/p n4 call pulse movlw 0x39 andwf PORTA,f ;clear o/p, all servos call frame ;test _save btfsc _save goto kal2 ;save not requested ;save data movf myaddr,w movwf _temp ;decrement clrc rlf _temp,f ;times 4 rlf _temp,f clrw ;test hi/lo btfss _hilo movlw 2 addwf _temp,f ;save to EERAM, address is in tmp, data in CC,DD comf CC,w ;un-negate so times can be read in microseconds movwf EE comf DD,w movwf FF movf _temp,w movwf CC ;address movf EE,w movwf DD ;data call WRAM ;LSByte incf CC,f ;address movf FF,w movwf DD ;data call WRAM bcf _led ;light out ;wait for _save to be released clrwdt btfss _save goto $-2 goto kal2 ;round again ; ;have to change _kal and restart to exit ; ;----------------------- ;---Reserve Copyright--- ;----------------------- ;new page ex org 200h da "Copyright Reserved, G.C.Hartnup: July 2002" ;----------- ;---EERAM--- ;----------- me org 2100H ;servo pulse lengths (lo and hi bytes) in microseconds ;Set the limit values required to get the positions you want for each servo ;The lower and higher values of 1000 and 2000 microseconds give 90 degrees travel ;When setting data, Low and High means upper and lower bytes of the hexadecimal value. ;The full stop indicates a decimal value ;These are default values to give 90 degree throw ;Calibration mode will overwrite them ;channel 1 de Low .1000 de High .1000 de Low .2000 de High .2000 ;channel 2 de Low .1000 de High .1000 de Low .2000 de High .2000 ;channel 3 de Low .1000 de High .1000 de Low .2000 de High .2000 ;channel 4 de Low .1000 de High .1000 de Low .2000 de High .2000 end