;************************************************************************************ ; Software License Agreement ; ; The software supplied herewith by Microchip Technology Incorporated (the "Company") ; for its PICmicro(r) Microcontroller is intended and supplied to you, the Company's ; customer, for use solely and exclusively on Microchip PICmicro Microcontroller ; products. ; ; The software is owned by the Company and/or its supplier, and is protected under ; applicable copyright laws. All rights are reserved. Any use in violation of the ; foregoing restrictions may subject the user to criminal sanctions under applicable ; laws, as well as to civil liability for the breach of the terms and conditions of ; this license. ; ; THIS SOFTWARE IS PROVIDED IN AN "AS IS" CONDITION. NO WARRANTIES, WHETHER EXPRESS, ; IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF ; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE ; COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR ; CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER. ; ;************************************************************************************ ; ; Filename: stepper.asm ; Date: 04/04/05 ; File Version: 1.00 ; Company: Microchip Technology Inc. ; ; ;************************************************************************************ ; ; Files required: ; stepperinc.inc ; ; ;************************************************************************************ ; ; Notes: ; This file implements single-stepping, half-stepping, and micro-stepping for ; a bipolar stepper motor. Cycle trought the different modes by pressing SW2. ; Adjust the speed of the motor with POT1. ; ; Connections: ; AN0 to POT1 ; RA4 to SW2 ; RD7 to P1 ; RD6 to P2 ; RD5 to P3 ; RD4 to P4 ; CCP1 to PWM1 ; CCP2 to PWM3 ; Place three shunts vertically on J2 ; Place three shunts vertically on J3 ; Drive 1 to Brown wire ; Drive 2 to Orange wire ; Drive 3 to Red wire ; Drive 4 to Yellow wire ; ;************************************************************************************ #include STARTUP code goto Initialize PORT1 code ;************************************************************************************ ; Initialize - Initialize CCP1, comparators, internal oscillator, I/O pins, ; analog pins, motor parameters, variables ; ;************************************************************************************ Initialize bsf STATUS,RP0 ; bank 1 bcf TRISC,5 ; Output: RC5 movlw b'00001011' ; Outputs: RD2,RD4-RD7 movwf TRISD movlw b'01110000' ; 8Mhz movwf OSCCON movlw b'00000001' ; enable AN0 movwf ANSEL movwf b'01010000' ; Fosc/16 movwf ADCON1 ;movlw 0x3F ; 31.2 kHz PWM movlw 0xEF ; PWM frequency changed for simulation purposes. movwf PR2 movlw b'00000000' ; 1:2 prescaler for TMR0 movwf OPTION_REG bcf STATUS,RP0 ; bank 0 clrf PORTD ; turn off windings clrf PORTC movlw b'00000001' ; left justified, AN0 selected, module on movwf ADCON0 movlw 0x07 movwf CMCON0 ; turn off comparators clrf CCPR1L clrf CCPR2L movlw b'00001100' ; pwm mode movwf CCP1CON movwf CCP2CON bsf T2CON,TMR2ON ; turn on PWM bsf T1CON,TMR1ON ; turn on Timer 1 clrf State ; initialize motor state pointer and duty cycle clrf Index ; index pointer clrf Mode clrf ADRESH movlw 1 movwf StepModeScaler movwf Counter clrf Speed clrf ButtonState ; initialize button state ;************************************************************************************ ; Main - Choose motor mode ; ;************************************************************************************ Main btfss INTCON,T0IF ; Wait 2.5ms goto Main bcf INTCON,T0IF call ButtonPress ; Call the button press debounce routine btfsc STATUS,C ; The carry flag is set if a button press just occurred incf Mode,f ; Change to the next state when a button press occurs. decfsz Counter,f ; This is the scaler for different stepping modes goto Main movf StepModeScaler,w movwf Counter decfsz Speed,f ; Delay counter goto Main comf ADRESH,w ; Set speed of motor btfsc STATUS,Z ; If zero, then make 255 sublw 1 movwf Speed ; Store in speed variable bsf ADCON0,GO_DONE ; start another ADC convertion goto ModeStateMachine ModeStateMachine ; Select stepping mode movlw high ModeTable movwf PCLATH movf Mode,w andlw 0x03 addlw low ModeTable btfsc STATUS,C incf PCLATH,f movwf PCL ModeTable goto SingleStep goto HalfStep goto MicroStep clrf Mode goto ModeTable ;************************************************************************************ ; SingleStep - Single Step the motor ; ;************************************************************************************ SingleStep movlw 8 movwf StepModeScaler incf State,f ; Increment motor state movlw 0xFF ; Turn off PWMs movwf CCPR1L movwf CCPR2L movlw 0x30 iorwf CCP1CON,f iorwf CCP1CON,f SingleStateMachine ; jump to motor state based on State pointer movlw high SingleJumpTable movwf PCLATH movf State,w andlw 0x03 addlw low SingleJumpTable btfsc STATUS,C incf PCLATH,f movwf PCL SingleJumpTable goto SingleState0 goto SingleState1 goto SingleState2 goto SingleState3 SingleState0 movlw CTRL1FWD movwf PORTD goto Main SingleState1 movlw CTRL2REV movwf PORTD goto Main SingleState2 movlw CTRL1REV movwf PORTD goto Main SingleState3 movlw CTRL2FWD movwf PORTD goto Main ;************************************************************************************ ; HalfStep - Half Step the motor ; ;************************************************************************************ HalfStep movlw 4 movwf StepModeScaler incf State,f movlw 0x30 iorwf CCP1CON,f iorwf CCP1CON,f HalfStateMachine ; jump to motor state based on State pointer movlw high HalfJumpTable movwf PCLATH movf State,w andlw 0x07 addlw low HalfJumpTable btfsc STATUS,C incf PCLATH,f movwf PCL HalfJumpTable goto HalfState0 goto HalfState1 goto HalfState2 goto HalfState3 goto HalfState4 goto HalfState5 goto HalfState6 goto HalfState7 HalfState0 movlw CTRL1FWD movwf PORTD movlw 0x3F movwf CCPR1L movwf CCPR2L goto Main HalfState1 movlw CTRL1FWD | CTRL2REV movwf PORTD movlw 0x2F movwf CCPR1L movwf CCPR2L goto Main HalfState2 movlw CTRL2REV movwf PORTD movlw 0x3F movwf CCPR1L movwf CCPR2L goto Main HalfState3 movlw CTRL2REV | CTRL1REV movwf PORTD movlw 0x2F movwf CCPR1L movwf CCPR2L goto Main HalfState4 movlw CTRL1REV movwf PORTD movlw 0x3F movwf CCPR1L movwf CCPR2L goto Main HalfState5 movlw CTRL1REV | CTRL2FWD movwf PORTD movlw 0x2F movwf CCPR1L movwf CCPR2L goto Main HalfState6 movlw CTRL2FWD movwf PORTD movlw 0x3F movwf CCPR1L movwf CCPR2L goto Main HalfState7 movlw CTRL2FWD | CTRL1FWD movwf PORTD movlw 0x2F movwf CCPR1L movwf CCPR2L goto Main ;************************************************************************************ ; MicroStep - Micro step the motor ; ;************************************************************************************ MicroStep movlw 1 movwf StepModeScaler call DutyCycleLookup ; lookup duty cycle value btfss STATUS,C ; if DutyCycleLookup sets carry variable then it's time goto MicroStateMachine ; to change state incf State,f MicroStateMachine ; jump to motor state based on State pointer movlw high MicroJumpTable movwf PCLATH movf State,w andlw 0x03 addlw low MicroJumpTable btfsc STATUS,C incf PCLATH,f movwf PCL MicroJumpTable goto MicroState0 goto MicroState1 goto MicroState2 goto MicroState3 ; 0 - CTRL1FWD ascending, CTRL2FWD decending ; 1 - CTRL1FWD decending, CTRL2REV ascending ; 2 - CTRL1REV ascending, CTRL2REV decending ; 3 - CTRL1REV decending, CTRL2FWD ascending MicroState0 movlw CTRL1FWD | CTRL2FWD movwf PORTD goto Main MicroState1 movlw CTRL1FWD | CTRL2REV movwf PORTD goto Main MicroState2 movlw CTRL1REV | CTRL2REV movwf PORTD goto Main MicroState3 movlw CTRL1REV | CTRL2FWD movwf PORTD goto Main ;************************************************************************************ ; DutyCycleLookup - Lookup duty cycle value based on motor state, direction, and duty ; cycle index. Move this 8-bit value into CCPxCON(LS 2-bits) and ; CCPRxL(HS 6-bits). ; ;************************************************************************************ DutyCycleLookup ; Winding 1 duty cycle lookup btfss State,0 call DutyCycleDec btfsc State,0 call DutyCycleAsc movwf DutyCycle ; move least significant 2 bits of duty cycle into swapf DutyCycle,w ; bits 4 and 5 of CCP2CON andlw 0x30 iorlw 0x8D movwf CCP2CON rrf DutyCycle,f ; move most significant 6 bits of duty cycle into rrf DutyCycle,w ; CCPR2L andlw 0x3F movwf CCPR2L ; Winding 2 duty cycle lookup btfss State,0 call DutyCycleAsc btfsc State,0 call DutyCycleDec movwf DutyCycle ; move least significant 2 bits of duty cycle into swapf DutyCycle,w ; bits 4 and 5 of CCP1CON andlw 0x30 iorlw 0x8D movwf CCP1CON rrf DutyCycle,f ; move most significant 6 bits of duty cycle into rrf DutyCycle,w ; CCPR1L andlw 0x3F movwf CCPR1L incf Index,f ; increment duty cycle index movf Index,w andlw 0x07 ; if Index has reached end of table it's time xorlw 0 ; to change states - indicate this by setting bsf STATUS,C ; the carry bit btfss STATUS,Z bcf STATUS,C return ;************************************************************************************ ; DutyCycleDec - Descending duty cycle lookup table ; ;************************************************************************************ DutyCycleDec movlw high DutyCycleDecTable movwf PCLATH movf Index,w andlw 0x07 addlw low DutyCycleDecTable btfsc STATUS,C incf PCLATH,f movwf PCL DutyCycleDecTable retlw .255 retlw .249 retlw .230 retlw .199 retlw .159 retlw .111 retlw .57 retlw .0 ;************************************************************************************ ; DutyCycleAsc - Ascending duty cycle lookup table ; ;************************************************************************************ DutyCycleAsc movlw high DutyCycleAscTable movwf PCLATH movf Index,w andlw 0x07 addlw low DutyCycleAscTable btfsc STATUS,C incf PCLATH,f movwf PCL DutyCycleAscTable retlw .0 retlw .57 retlw .111 retlw .159 retlw .199 retlw .230 retlw .249 retlw .255 ;************************************************************************************ ; ButtonPress - When the button is first pressed this function sets the carry flag to ; indicate it's time to change modes. Then the function debounces the switch to ; ensure one button press by the user is interpreted as one button press by the ; microcontroller ; ;************************************************************************************ ButtonPress movlw high DebounceStates movwf PCLATH movf ButtonState,w andlw 0x03 addlw low DebounceStates btfsc STATUS,C incf PCLATH,f movwf PCL DebounceStates goto DebounceState0 goto DebounceState1 goto DebounceState2 goto DebounceState1 DebounceState0 ; Wait for a Button Press bcf STATUS,C btfsc SW2 goto EndDebounceState0 incf ButtonState,f bsf STATUS,C EndDebounceState0 return DebounceState1 btfss SW2 goto EndDebounceState1 incf ButtonState,f clrf TMR1L clrf TMR1H bcf PIR1,TMR1IF EndDebounceState1 bcf STATUS,C return DebounceState2 btfss SW2 decf ButtonState,f btfsc PIR1,TMR1IF clrf ButtonState bcf STATUS,C return END ; directive 'end of program'