;***************************************************************************** ; reverser.asm Servo Reverser ;***************************************************************************** ; Bruce Abbott bhabbott@paradise.net.nz ; ; for Microchip 12F615, 12F675 or 12F683 ; ;============================================================================= ; Summary of Changes ; ; 2008/06/03 V0.0 - Created ; 2010/04/30 - changed version string to suit PICkit2 ; 2010/05/16 V0.1 - changed I/O pin assignments for better board layout ; - added option jumper ; ----------------------------------------------------------------------------- #DEFINE version " 0 . 1" ;#DEFINE __12F615 ; MPLAB users should use menu ;#DEFINE __12F675 ;#DEFINE __12F683 ifdef __12F615 PROCESSOR PIC12F615 INCLUDE #DEFINE RAMSTART 0x40 __CONFIG _MCLRE_OFF&_CP_OFF&_WDT_ON&_IOSCFS_4MHZ&_INTRC_OSC_NOCLKOUT endif ifdef __12F675 PROCESSOR PIC12F675 INCLUDE #DEFINE RAMSTART 0x20 __CONFIG _MCLRE_OFF&_CP_OFF&_WDT_ON&_BODEN_ON&_INTRC_OSC_NOCLKOUT endif ifdef __12F683 PROCESSOR PIC12F683 INCLUDE #DEFINE RAMSTART 0x20 __CONFIG _MCLRE_OFF&_CP_OFF&_WDT_ON&_BOD_ON&_INTRC_OSC_NOCLKOUT endif errorlevel 0,-305,-302 radix dec ; decimal numbers ; options ;#DEFINE TRIM1 1 ; trimpot affects output 1 ;#DEFINE TRIM2 1 ; trimpot affects output 2 ;#DEFINE STATUSLED 1 ; status LED active ; Bit definitions for the GPIO register and the TRIS register #DEFINE JP1 0 ; pin 7 (GP0) option jumper #DEFINE SERVO1 1 ; pin 6 (GP1) 1st servo output (1~2mS pulse) normal #DEFINE SERVO2 2 ; pin 5 (GP2) 2nd servo output (1~2mS pulse) inverted #DEFINE PULSE 3 ; pin 4 (GP3) servo input (1~2mS pulse) #DEFINE POT 4 ; pin 3 (GP4) trim pot, input to A/D #DEFINE LED 5 ; pin 2 (GP5) status indicator. Active Low (LED+resistor to Vcc) ifdef STATUSLED #DEFINE TrisBits (1<= 0 ENDM add16 MACRO al, bl ;b=b+a movf al,W addwf bl,F movf al+1,W skpnc incfsz al+1,W addwf bl+1,F ENDM sub16 MACRO al,bl ;b=b-a movf al,W subwf bl,F movf al+1,W skpc incfsz al+1,W subwf bl+1,F ; If C then a1 >= a2 ENDM rr16 MACRO al ;a=a/2 rrf al+1 rrf al ENDM rl16 MACRO al ;a=a*2 rlf al rlf al+1 ENDM inc16 MACRO al ;a=a+1 incfsz al decf al+1 incf al+1 ENDM dec16 MACRO al ;a=a-1 tstf al skpnz decf al+1 decf al ENDM com16 MACRO al ; a = NOT a comf al comf al+1 ENDM movi16 MACRO val, dest ;dest=val movlw val % 0x0100 movwf dest movlw val / 0x0100 movwf dest+1 ENDM mov16 MACRO src, dest ;dest=src movf src,w movwf dest movf src+1,w movwf dest+1 ENDM ;========================================================================== ; Macro for generating short time delays ; NO_OP MACRO count NO_OP_COUNT SET count WHILE NO_OP_COUNT>1 goto $+1 ; 2 clocks NO_OP_COUNT SET NO_OP_COUNT-2 ENDW IF NO_OP_COUNT nop ; 1 clock ENDIF ENDM ;=========================================================================== ; Macros to create offsets for variables in RAM ; ByteAddr SET RAMSTART ; 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 ; ========================================================================== ; RAM Variable Definitions ; BYTE Flags ; various boolean flags WORD PulseCount ; measured input pulse width 0.9~2.1mS WORD LastCount ; previous pulse width WORD ServoCount ; servo output pulse width WORD Servo1 ; 1st servo output pulse width WORD Servo2 ; 2nd servo output pulse width WORD Trim ; servo trim value WORD PotVolts ; Potentiometer Voltage BYTE Glitches ; number of consecutive bad servo pulses BYTE Temp1 BYTE Temp2 BYTE t1 WORD aa ; 16 bit working register WORD AARGB0 ; 16 bit working register BYTE w_temp ; interrupt context storage BYTE FSR_temp BYTE status_temp ; flag values ; #DEFINE WATCH 0 ; Watchdog timed out #DEFINE GOT_FS 1 ; got failsafe value #DEFINE PULSEHI 2 ; servo pulse was high #DEFINE GOTPULSE 3 ; got servo pulse input #DEFINE BADPULSE 4 ; bad servo pulse input ;**************************************************************************** ; Code ; ORG 0 goto ColdStart ; jump to power-on startup ORG 4 goto isr ; jump to interrupt service routine ;-------------------------- version string ---------------------------------- org 8 dw " R V S R" ifdef __12F615 dw " 6 1 5 " endif ifdef __12F675 dw " 6 7 5 " endif ifdef __12F683 dw " 6 8 3 " endif dw " V" dw version ;============================================================================ isr: movwf w_temp movf STATUS,w movwf status_temp ; save registers movf FSR,w movwf FSR_temp bcf STATUS,RP0 ; page zero btfsc PIR1,TMR1IF ; Timer 1 overflow ? goto long_pulse btfsc GPIO,PULSE ; leading edge of pulse detected ? goto pulse_high ; yes pulse_low: btfss Flags,PULSEHI ; was pulse high ? goto pulse_done ; no, exit bsf Flags,GOTPULSE bcf INTCON,GPIF ; clear pin change interrupt nop bcf T1CON,TMR1ON ; Stop timer1 movf TMR1L,w movwf PulseCount movf TMR1H,w ; get timer1 value movwf PulseCount+1 goto exit_isn ; done pulse_high: bcf T1CON,TMR1ON ; Stop timer1 movlw (0)%256 movwf TMR1L ; load timer1 movlw (0)/256 movwf TMR1H bsf T1CON,TMR1ON ; start timer1 bsf Flags,PULSEHI ; now waitng for pulse low pulse_done: bcf INTCON,GPIF ; clear pin change interrupt ; exit and enable interrputs exit_isr: movf FSR_temp,w movwf FSR movf status_temp,w ; restore registers movwf STATUS swapf w_temp,f swapf w_temp,w retfie ; Timer1 overflow long_pulse: bcf T1CON,TMR1ON ; Stop timer1 bcf PIR1,TMR1IF ; clear timer1 interrupt bsf Flags,BADPULSE ; bad pulse ! ; exit with interrupts disabled exit_isn: movf FSR_temp,w movwf FSR movf status_temp,w ; restore registers movwf STATUS swapf w_temp,f swapf w_temp,w return ;=========================================================================== ; Startup from Power On or Watchdog Timeout ; ColdStart: bcf Flags,WATCH btfss STATUS,NOT_TO ; copy Watchdog timeout flag bsf Flags,WATCH ; 12F683: set internal oscillator frequency ifdef __12F683 bsf STATUS,RP0 movlw b'01100001' ; 4MHz internal RC Oscillator movwf OSCCON bcf STATUS,RP0 endif ; 12F675: get oscillator calibration value and use it to fine-tune clock frequency. ifdef __12F675 bsf STATUS,RP0 ; register bank 1 (12F629/75) call 0x3ff ; get OSCCAL value movwf OSCCAL ; set oscillator calibration bcf STATUS, RP0 ; register bank 0 endif ; set options bsf STATUS,RP0 ; register bank 1 movlw OptionBits movwf OPTION_REG bcf STATUS,RP0 ; register bank 0 ;======================================================================== ; initialise I/O registers clrf GPIO ; all outputs off banksel TRISIO ; register bank 1 movlw TrisBits movwf TRISIO ; set I/O pin directions banksel 0 ; register bank 0 ifdef __12F615 movlw b'00000000' movwf CMCON0 ; Comparator off movwf CCP1CON ; CCP module off endif ifdef __12F675 movlw b'00000111' movwf CMCON ; Comparator off endif ifdef __12F683 movlw b'00000111' movwf CMCON0 ; comparator off movlw b'00000000' movwf CCP1CON ; CCP module off endif ; set up A/D convertor banksel ANSEL movlw b'00011000' ; clk/8, AN3 active movwf ANSEL banksel 0 movlw b'00001101' ; left-justify, Vdd ref, input AN3, A/D on movwf ADCON0 ; CPU specific stuff done, now we can start the main program! goto Main ;======================================================================== ; Read Potentiometer Voltage ; ReadPot: movlw 64 ; 64 x oversampling movwf Temp1 clrf PotVolts ; no sample yet! clrf PotVolts+1 pot_read: bsf ADCON0,GO ; start A/D conversion pot_wait: btfsc ADCON0,GO ; wait until A/D done goto pot_wait movf ADRESH,w ; get A/D value 0-255 addwf PotVolts skpnc ; accumulate readings incf PotVolts+1 decfsz Temp1 ; next reading goto pot_read movlw 6 movwf Temp1 ; 2^6 = 64 pot_divide: clrc rr16 PotVolts ; divide by 64 decfsz Temp1 goto pot_divide return ;**************************** SERVO OUT ******************************** ; ; based on code by mmormota ; http://www.rcgroups.com/forums/showthread.php?t=624290 ; ; 16 bit input expected in Servo1, Servo2 ; ; Pulses start consecutively, with 1uS resolution. ; pulses end (almost) simultaneously, with 32uS resolution. ; ; ________________ ; Servo1 ___////////// \ \ \ \_____ ; 0~32uS 32uS*(pulse/32) ; ________ ; Servo2 _____________/////////// \ \ \ \_____ ; 0~32uS 32us*(pulse/32) ; servo_out: subi16 83,Servo1 subi16 26,Servo2 ; do microsecond part of timing loop. Always takes 32+uS per channel. ; Each servo pulse starts somewhere (0~31uS) inside its 32uS window. ; servo 1 comf Servo1 movf Servo1,w andlw b'00011111' call usdelay ; delay 31-0uS bsf GPIO,SERVO1 ; start servo output pulse comf Servo1 movf Servo1,w andlw b'00011111' call usdelay ; delay 0~31uS ; servo 2 comf Servo2 movf Servo2,w andlw b'00011111' call usdelay ; delay 31~0uS bsf GPIO,SERVO2 ; start servo output pulse comf Servo2 movf Servo2,w andlw b'00011111' call usdelay ; delay 0~31uS ; divide pulse widths by 32 movlw 5 ; shift right * 5 = divide by 32 movwf t1 servooutdiv: rr16 Servo1 rr16 Servo2 decfsz t1,f goto servooutdiv ; do 32us part of timing. Each channel is ended when its time is ; up, in 32uS steps. movlw 78 ; 78*32 = ~2.5mS maximum pulse width movwf t1 servoout32: decf Servo1 skpnz bcf GPIO,SERVO1 ; end servo1 ouput pulse decf Servo2 skpnz bcf GPIO,SERVO2 ; end servo2 output pulse movlw 32-21 call usdelay ; wait 32uS (-overhead) decfsz t1 goto servoout32 ; next 32uS bcf GPIO,SERVO1 bcf GPIO,SERVO2 ; ensure that outputs are done! return ;****************** General purpose functions **************************** ;---------------------------------------------------------------- ; 11~266 Microsecond Delay ;---------------------------------------------------------------- ; Input: w = delay time in microseconds -11 ; usdelay: addlw -4 skpnc goto usdelay sublw -1 addwf PCL,f nop nop nop nop return ;---------------------------------------------------------------- ; Millisecond Delay ;---------------------------------------------------------------- ; Input: w = delay time in microseconds ; delay1ms: ; 1 millisecond delay movlw -8 ; preset countdown value to W delayx4us: addlw -1 ; subtract 1 btfsc STATUS,C goto delayx4us return ;------------------------------------------------------------------------------- ; Millisecond Delay Timer ;------------------------------------------------------------------------------- ; Input: W = number of milliseconds to wait (max 256mS) ; dx1k: movwf Temp1 _dx1k1: movlw (1000-5)/5 movwf Temp2 _dx1k2: clrwdt ; avoid watchdog timeout nop decfsz Temp2 ; wait 1mS goto _dx1k2 decfsz Temp1 goto _dx1k1 retlw 0 ;******************************************************************************* ; Main ;******************************************************************************* Main: btfsc Flags,WATCH ; did the watchdog timeout ? goto Restart ; oops! try to keep going ... clrf Flags ; clear all flags bsf GPIO,LED ; signal LED on movlw 250 ; wait 250mS for power to stabilise call dx1k Restart: bcf GPIO,LED ; signal LED off WaitHigh: clrwdt ; avoid watchdog timeout btfsc GPIO,PULSE ; wait for start of servo pulse goto WaitHigh WaitLow: clrwdt ; avoid watchdog timeout btfsc GPIO,PULSE ; wait for end of servo pulse goto WaitLow banksel IOC movlw b'00001000' ; enable Int On Change GP3 movwf IOC banksel 0 bsf INTCON,GPIE ; enable IOC interrupts MainLoop: bcf T1CON,TMR1ON ; Stop timer1 bcf Flags,BADPULSE bcf Flags,GOTPULSE bcf INTCON,T1IF ; clear Timer1 interrupt movf GPIO,w bcf INTCON,GPIF ; clear pin change int bsf INTCON,GIE ; enable interrupts globally ; wait for isr to receive servo pulse wait_pulse: clrwdt btfsc Flags,BADPULSE ; isr detected noise ? goto no_signal btfss Flags,GOTPULSE ; isr received pulse ? goto wait_pulse got_pulse: clrwdt movlw 10 subwf PulseCount+1,w skpnc ; pulse too long ? goto bad_pulse movlw 2 subwf PulseCount+1,w skpc ; pulse too short ? goto bad_pulse bsf GPIO,LED ; signal LED on mov16 PulseCount,ServoCount Process: mov16 ServoCount,Servo1 ; output1 = normal mov16 ServoCount,aa movi16 1500,Servo2 ; mid-point = 1.5mS sub16 Servo2,aa sub16 aa,Servo2 ; output2 = reversed btfss GPIO,JP1 ; trimpot enabled? goto do_output ; no, call ReadPot ; yes, get pot position mov16 PotVolts,Trim ifdef TRIM1 add16 Trim,Servo1 subi16 127,Servo1 ; trim output1 endif ifdef TRIM2 add16 Trim,Servo2 subi16 127,Servo2 ; trim output2 endif do_output: call servo_out ; send pulses to servos goto done bad_pulse: no_signal: clrwdt bcf GPIO,LED ; LED off ; all done, loop back for next input pulse done: goto MainLoop ;------------------ Oscillator Calibration Subroutine ----------------------- ; ; Only required if the original factory programmed value has been erased. ; ; NOTE: You should read the factory programmed value and record it, BEFORE ; programming your 12F675! ifdef __12F675 org 0x3ff retlw 0x80 ; replace with OSCCAL value for your PIC endif END