|
I have enclosed a program that I a working on and am trying to get this program to work properly. My motor is not stopping. Example: If I want my motor to stop at 90 degrees with a 1.2498 voltage applied via the POT (potentiometer). My motor is continually running and not stopping based on my POT adjustments. Any ideas would be greatly appreciated from a frustrated student, who is on Spring break and NOT in Mexico! I have enclosed my program (MINIIDE) for your perusal. I want to operate in the half-step mode. THANKS, Jackie |
Stepper Motors using the 68HC12
Started by ●March 25, 2004
Reply by ●March 25, 20042004-03-25
|
I have added a program that I a working on and am trying to get this program to work properly. My motor is not stopping. Example: If I want my motor to stop at 90 degrees with a 1.2498 voltage applied via the POT (potentiometer). My motor is continually running and not stopping based on my POT adjustments. Any ideas would be greatly appreciated from a frustrated student, who is on Spring break and NOT in Mexico! I have added my program for your perusal. I want to operate in the half-step mode. THANKS, Jackie THANKS to the individual who brought to my attention that I can not attach documents. ******************************************************** * This is a program showing the use * of the A/D converter. * The program will convert the voltage from * the kit's potentiometer that is connected to * the ADC's AN07 input pin.* * The program stores the result at adr07h* * The default for ATDCTL5: left justified data, unsigned,* * single conversion sequence, one channel sample, channel AN0* ******************************************************** * Constant Equates *A/D control and status registers ATDCTL2 EQU $82 ATDCTL3 EQU $83 ATDCTL4 EQU $84 ATDCTL5 EQU $85 ATDSTAT0 EQU $86 ; A/D status register (SCF) ATDSTAT1 EQU $87 ; A/D status register (CCF) *************************************************************** *ADC Results Registers* ADR0H EQU $90 ; 10 bit values take ADR0L EQU $91 ; 2 bytes of storage ADR1H EQU $92 ; Left justified have MSB ADR1L EQU $93 ; in high byte, bits 1,0 are ADR2H EQU $94 ; stored in b7,6 of low byte ADR2L EQU $95 ; ADR3H EQU $96 ; Right justified have LSB ADR3L EQU $97 ; stored in low byte, bits 9,8 ADR4H EQU $98 ; stored in b1,0 of high byte. ADR4L EQU $99 ; ADR5H EQU $9A ; 8 bit values ADR5L EQU $9B ; Left justified ADR6H EQU $9C ; stored in high bytes. ADR6L EQU $9D ; Right justified ADR7H EQU $9E ; stored in low bytes ADR7L EQU $9F ; of result registers. *************************************************************** *ATDCL2 Register Control Bits* *All bits are clear on reset* ADPU EQU %10000000 ; A/D power up bit, Set to power up AFFC EQU %01000000 ; Set to Fast Clear all CCF flags AWAI EQU %00100000 ; Set to power down A/D in wait mode ETRIGE EQU %00000100 ; Set to Enable external trigger ETRIGLE EQU %00010000 ; Set to Level Triggered (Clear for Edge) ETRIGP EQU %00001000 ; Set for Rising Edge or High Level ASCIE EQU %00000010 ; Set to enable ATD interrupt ASCIF EQU %00000001 ; Set by ATD when interrupt conversion complete *If AFFC is cleared then the CCF flag is reset only when* *ATDSTAT1 and the A/D results register(s) are read.* *If AFFC is set then the SCF flag is reset only when* *conversion sequence has completed and results read* *ASCIF is read only *************************************************************** *ATDCTL3 Register Control Bits *SC EQU %0xxxx 000 ; # of conversions in sequence, 1 to 8 (4 bits) FIFOATD EQU %00000100 ; Set to wrap around conversion results SC EQU %00001000 ; one conversion *************************************************************** *ATDCL4 Register Control Bits *Reset value is$05 (prescalar bits)* SRES8 EQU %10000000 ; Resolution, Set = 8 bit SMP EQU %01100000 ; SMP1 and SMP0 Sample Time Bits *PRS EQU %000xxxxx ; PRS Clock Prescalar Bits PRS EQU %00010111 ; PRS bits for this program *default resolution is 10 bits* *************************************************************** *ATDCL5 Register Control Bits* *All bits are clear on reset* JUSTIFY EQU %10000000 ; Set for right justification SIGN EQU %01000000 ; Set for signed number representation SCAN EQU %00100000 ; Set for continuous conversions MULT EQU %00010000 ; Set to sample multiple channels *AN EQU %00000xxx ; ATD Input Channel Number 0 to 7 (3 bit number) AN EQU %00000111 ; Using channel 7 for this program *************************************************************** *ATD Status Register 0 (ATDSTAT0)* *All bits are clear on reset* *The values of these constants are AND'd with ATDSTAT0. If the *result is non-zero, then the flag is set. If the result is zero then *the flag was not set by the ATD* SCF EQU %10000000 ; Sequence conversion Complete Flag ETORF EQU %00100000 ; Ext Trigger Overrun Flag FIFOR EQU %00010000 ; FIFO Overrun Flag *CC EQU %00000xxx ; 3 bit Conversion Counter (R only) *Writing a 1 to the SCF clears it* *FIFO indicates a register has been overwritten before* *it has been read.* *CC points to the next register to be used by the ATD* *************************************************************** *ATD Status Register 1 (ATDSTAT1)* *All bits are clear on reset* *CCF is used in a similar manner to the flags of ATDSTAT0 CCF EQU %11111111 ; Set by ATD for each results register *after it receives a value, if AFFC=0 reading ATDSTA1 and then* *a results register clears a CCF flag for each individual results register* *All cleared by a write to ATDCTL5* *If AFFC=1 a zero in a CCF bit indicates conversion number x has* *not completed.* *************************************************************** * Memory Map Equates *************************************************************** ;CODE EQU $1000 ;DATA EQU $1050 ;STACK EQU $3000 ; Remember that debug uses memory. ;DDRB EQU $0003 ;PORTB EQU $0001 *************************************************************** org CODE lds #STACK ldab #$FF ; Load B with %11111111 stab DDRB ; Makes portb an output port. clrb ; Clears acc. B ; Power up the A/D bset ATDCTL2 ADPU ; OR function, wakes up ADC. ; Generate a "short" delay > ? microsec to let ADC settle. ldaa #$FF ; FF loops for. short: nop ; 2 times FF loops dbne a,short ; Decriment acc. A and branch to delay. ; Now set up the A/D. ; Normal flag clearing, run in WAIT mode, no interrupts. bclr ATDCTL2 AFFC|AWAI|ASCIE|ETRIGE ; Clrears all the positions stated ; on the ATDCLT2. ; Mask bits are inverted and AND'd with ATDCTL2. ; Any mask bit that is a '1' clears the corresponding bit in ATDCTL2. Here we clear four bits. bclr ATDCTL3 #$FF ; Clear all bits bset ATDCTL3 SC ; 1 conversion needed for an7 ; The bus speed is 24 MHz. To obtain the slowest conversion time select the longest sample time ; and an ATD conversion clock frequency of 500kHz. Sample time: SMP1:SMP2 = 1:1 ; PRS = 10111, gives ATD ccf of 500kHz Conversion time = 32uS. bclr ATDCTL4 #$FF ; Clears ATDCLT4 and makes it ready for bit setting. bset ATDCTL4 #$60 ; Select 16 X sample time. bset ATDCTL4 PRS ; Set PRS, Divide 24 MHz by 48. bset ATDCTL4 SRES8 ; Use 8-bit conversion mode. ; Start the conversion by writing the scan select information to ATDCTL5. ; First change the ATD mode. top: bset ADMODE JUSTIFY ; Set %10000000 in ADMODE. bset ADMODE AN ; Set %00000111 in ADMODE. ldaa ADMODE ; Load acc. A with ADMODE. bclr ATDCTL5 #$FF ; Clear ATDCLT5 with the inverted valve of #$FF. staa ATDCTL5 ; Starts conversion. ; And wait until conversion done. spin: brclr ATDSTAT0 SCF, spin ; A bitwise AND. ; So that as long as SCF = 0, the branch to 'spin' is taken. ; When the SCF flag in ATDSTAT = 1 the branch is not taken! clrb ; Clear acc. B ldab ADR0L ; Load acc. B with the voltage value that is on the ; board that is stored in ADR0L. stab PORTB ; Show the voltage value with the LED'S. bsr longdelay bra top swi ; Stop the program and look at the values. org code ADMODE db $0 longdelay ldx #$ffff ldy #$0188 time: dbne x, time dbne y, time rts ;Stepper Motor Controller ; The Diodes on Port B Represent Stepper Motor Control Transistors PORTB equ $0001 ;Port B register DDRB equ $0003 ;Port B Data Direction Register PORTP equ $0258 ;Port P register DDRP equ $025A ;Port P Data Direction Register RDRP equ $025B ;Port P Reduced Drive Register DELAY equ $0002 ;$ffff ;Delay for software timing loops COUNTNUM equ 48 ;number of times to repeat CW direction CODE equ $1000 STACK equ $2000 ;STACK org CODE lds #STACK movb #$ff,DDRB ;make Port B all outputs movb #$00,PORTB ;clear Port B movb #$0f,DDRP ;make lower 4 bits Port P outputs movb #$00,PORTP ;clear Port P ldaa #COUNTNUM ;# of times to repeat CW direction staa count ;save count loop_CW jsr DelayM jsr Step_CW ;Step once CW (increment) ldaa Output_pattern ;load output pattern, setup by Step_CW staa PORTB ;output the pattern to diodes anda #$0F staa PORTP ;output the pattern to motor dec count bne loop_CW ;continue CW direction ldaa #COUNTNUM ;# of times to repeat CCW direction staa count loop_CCW jsr DelayM jsr Step_CCW ;Step once CCW (decrement) ldaa Output_pattern ;load output pattern, setup by Step_CCW staa PORTB ;output the pattern to diodes anda #$0F ;mask out upper 4 bits staa PORTP ;output the pattern to motor dec count bne loop_CCW ;continue CCW direction swi ;stop ;loop bra loop *************************************************** * * Step Clockwise Subroutine * * This subroutine controls clockwise rotation of the motors. * * Inputs: None * * Outputs: Ouput_pattern Modifies output pattern * Sequence_ptr Pointer to table of stepper commands * * Invokes: Nothing * *************************************************** Step_CW ldab Sequence_ptr ;Load Sequence pointer incb ;Increment to point to next * ;sequence value andb #$07 ;Restrict table addresses to lower 3 bits stab Sequence_ptr ;Save Sequence pointer clra ;Clear acc A addd #Step_Table ;Add address of Step Table xgdy ;Exchange D with Y so that * ;indirect addressing can be * ;performed again. ldab 0,y ;Load value from table stab Output_pattern ;Save output pattern rts ;Return *************************************************** * * Step Counter-Clockwise Subroutine * * This subroutine controls counter-clockwise rotation of the motors. * * Inputs: None * * Outputs: Output_pattern Modifies output pattern * Sequence_ptr Pointer to table of stepper commands * * Invokes: Nothing * *************************************************** Step_CCW ldab Sequence_ptr ;Load Sequence pointer decb ;Decrement to point to next * ;sequence value andb #$07 ;Keep lowest two bits stab Sequence_ptr ;Save Sequence pointer clra ;Clear acc A addd #Step_Table ;Add address of Step Table xgdy ;Exchange D with Y so that * ;indirect addressing can be * ;performed again. ldab 0,y ;Load value from table stab Output_pattern ;Save output pattern rts ;Return *************************************************** DelayM ldx #8 ;Have to delay so that mechanical motors ldy #$FFFF L1 dey bne L1 ;can keep up. dex bne L1 rts *************************************************** * * Step Table: * * This table contains the sequence to be output to cause the stepper * motors to turn. If followed from top to bottom, restarting the * sequence at the top when necessary, will cause the steppers to turn * clockwise. Following the sequence from bottom to top, restarting * the sequence at the bottom when necessary, the motors will turn * counter-clockwise. * *************************************************** org $1400 Step_Table * Full Step One Phase On dc.b $11 ;R dc.b $44 ;R dc.b $22 ;L dc.b $88 ;L ;*Full Step Two Phases On ;* dc.b $66 ; * dc.b $AA ; * dc.b $99 ; * dc.b $55 ; HalfStep dc.b $11 dc.b $55 dc.b $44 dc.b $66 dc.b $22 dc.b $AA dc.b $88 dc.b $99 count dc.b $00 ;Counts # of iterations Sequence_ptr dc.b $00 ;pointer to sequence to control motor Output_pattern dc.b $00 ;Pattern to output to port which ;controls the stepper motor board -----Original Message----- From: Jackie Johnson [mailto:] Sent: Thursday, March 25, 2004 8:52 AM To: ' Subject: Stepper Motors using the 68HC12 I have enclosed a program that I a working on and am trying to get this program to work properly. My motor is not stopping. Example: If I want my motor to stop at 90 degrees with a 1.2498 voltage applied via the POT (potentiometer). My motor is continually running and not stopping based on my POT adjustments. Any ideas would be greatly appreciated from a frustrated student, who is on Spring break and NOT in Mexico! I have enclosed my program (MINIIDE) for your perusal. I want to operate in the half-step mode. THANKS, Jackie |
|
|
Reply by ●March 26, 20042004-03-26
|
Jackie -- Which version of the HC12 are you using? One thing that jumps out is that you are using bset and bclr for registers. This isn't a good idea, since they are read/modify/write instructions, and have bad consequences under certain conditions. The safe thing is to get rid of all of them, and avoid them in the future for register manipulation. (They are fine for regular RAM.) Gary Olmstead Toucan Technology Ventura CA At 12:38 PM 3/25/04, you wrote: >I have added a program that I a working on and am trying to get this >program to work properly. My motor is not stopping. Example: If I >want my motor to stop at 90 degrees with a 1.2498 voltage applied via >the POT (potentiometer). My motor is continually running and not >stopping based on my POT adjustments. Any ideas would be greatly >appreciated from a frustrated student, who is on Spring break and NOT in >Mexico! > >I have added my program for your perusal. I want to operate in the >; Power up the A/D > > bset ATDCTL2 ADPU ; OR function, wakes up ADC. > >; Generate a "short" delay > ? microsec to let ADC settle. > > ldaa #$FF ; FF loops for. > short: nop ; 2 times FF loops > dbne a,short ; Decriment acc. A and branch to > > bclr ATDCTL2 AFFC|AWAI|ASCIE|ETRIGE ; Clrears all > bclr ATDCTL3 #$FF ; Clear all bits > bset ATDCTL3 SC ; 1 conversion needed for an7 > bclr ATDCTL4 #$FF ; Clears ATDCLT4 and makes it >ready for bit setting. > bset ATDCTL4 #$60 ; Select 16 X sample time. > bset ATDCTL4 PRS ; Set PRS, Divide 24 MHz by 48. > bset ATDCTL4 SRES8 ; Use 8-bit conversion mode. > >; Start the conversion by writing the scan select information to >ATDCTL5. >; First change the ATD mode. > > top: bset ADMODE JUSTIFY ; Set %10000000 in ADMODE. > bset ADMODE AN ; Set %00000111 in ADMODE. > ldaa ADMODE ; Load acc. A with ADMODE. > bclr ATDCTL5 #$FF ; Clear ATDCLT5 with the >inverted valve of #$FF. > staa ATDCTL5 ; Starts conversion. |
|
|
Reply by ●March 26, 20042004-03-26
|
Gary, Good morning from Alaska..I believe the version is M68HC12. The program that I included works fine EXCEPT it continues to "half-step". I am trying to figure out how to program this so that if I set the potentiometer (manually do this on the board) to 1.24 volts that the motor that it will step to it's 90 degrees and stay there until I adjust the POT again. Of course the LED's need to read the correct binary number for 1.24 volts. I am thinking that I will have to do a comparison, maybe a branch???? Thanks for your help. Jackie -----Original Message----- From: Gary Olmstead [mailto:] Sent: Friday, March 26, 2004 6:42 AM To: Subject: Re: [68HC12] FW: Stepper Motors using the 68HC12 Jackie -- Which version of the HC12 are you using? One thing that jumps out is that you are using bset and bclr for registers. This isn't a good idea, since they are read/modify/write instructions, and have bad consequences under certain conditions. The safe thing is to get rid of all of them, and avoid them in the future for register manipulation. (They are fine for regular RAM.) Gary Olmstead Toucan Technology Ventura CA At 12:38 PM 3/25/04, you wrote: >I have added a program that I a working on and am trying to get this >program to work properly. My motor is not stopping. Example: If I >want my motor to stop at 90 degrees with a 1.2498 voltage applied via >the POT (potentiometer). My motor is continually running and not >stopping based on my POT adjustments. Any ideas would be greatly >appreciated from a frustrated student, who is on Spring break and NOT in >Mexico! > >I have added my program for your perusal. I want to operate in the >; Power up the A/D > > bset ATDCTL2 ADPU ; OR function, wakes up ADC. > >; Generate a "short" delay > ? microsec to let ADC settle. > > ldaa #$FF ; FF loops for. > short: nop ; 2 times FF loops > dbne a,short ; Decriment acc. A and branch to > > bclr ATDCTL2 AFFC|AWAI|ASCIE|ETRIGE ; Clrears all > bclr ATDCTL3 #$FF ; Clear all bits > bset ATDCTL3 SC ; 1 conversion needed for an7 > bclr ATDCTL4 #$FF ; Clears ATDCLT4 and makes it >ready for bit setting. > bset ATDCTL4 #$60 ; Select 16 X sample time. > bset ATDCTL4 PRS ; Set PRS, Divide 24 MHz by 48. > bset ATDCTL4 SRES8 ; Use 8-bit conversion mode. > >; Start the conversion by writing the scan select information to >ATDCTL5. >; First change the ATD mode. > > top: bset ADMODE JUSTIFY ; Set %10000000 in ADMODE. > bset ADMODE AN ; Set %00000111 in ADMODE. > ldaa ADMODE ; Load acc. A with ADMODE. > bclr ATDCTL5 #$FF ; Clear ATDCLT5 with the >inverted valve of #$FF. > staa ATDCTL5 ; Starts conversion. --------------------To learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu o learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu _____ > Service. |
|
|
Reply by ●March 26, 20042004-03-26
|
At 08:46 AM 3/26/04, you wrote: >Gary, >Good morning from Alaska..I believe the version is M68HC12. Well, there are 10 versions of the 68HC12, and 19 of the MC9S12. What does it say on the top of the chip? >The program >that I included works fine EXCEPT it continues to "half-step". Is it half stepping before this point, or does it switch over to half step from something else? > I am >trying to figure out how to program this so that if I set the >potentiometer (manually do this on the board) to 1.24 volts that the >motor that it will step to it's 90 degrees and stay there until I adjust >the POT again. Of course the LED's need to read the correct binary >number for 1.24 volts. You've got two separate problems. What do the LEDs read when the input is at 0V? What do the LEDs read when the input is 1.24V? What do they read at 5V? > >I am thinking that I will have to do a comparison, maybe a branch???? First things first. Gary Olmstead Toucan Technology Ventura CA |
Reply by ●March 30, 20042004-03-30
|
Jackie, Looks to me like you had two or more programs that worked separately and you have stuck them together without realising that there are now three instances of 'org CODE'. The assembler will have overwritten previous 'ORGed' sections of program and has left you with only the stepper motor bit - hence the motor runs continuously. Even if you removed the duplicated ORGs, it's not clear how the ADC value is being used to drive the motor. Mike. ----- Original Message ----- From: Jackie Johnson To: Cc: Sent: Thursday, March 25, 2004 9:38 PM Subject: [68HC12] FW: Stepper Motors using the 68HC12 I have added a program that I a working on and am trying to get this program to work properly. My motor is not stopping. Example: If I want my motor to stop at 90 degrees with a 1.2498 voltage applied via the POT (potentiometer). My motor is continually running and not stopping based on my POT adjustments. Any ideas would be greatly appreciated from a frustrated student, who is on Spring break and NOT in Mexico! I have added my program for your perusal. I want to operate in the half-step mode. THANKS, Jackie THANKS to the individual who brought to my attention that I can not attach documents. ******************************************************** * This is a program showing the use * of the A/D converter. * The program will convert the voltage from * the kit's potentiometer that is connected to * the ADC's AN07 input pin.* * The program stores the result at adr07h* * The default for ATDCTL5: left justified data, unsigned,* * single conversion sequence, one channel sample, channel AN0* ******************************************************** * Constant Equates *A/D control and status registers ATDCTL2 EQU $82 ATDCTL3 EQU $83 ATDCTL4 EQU $84 ATDCTL5 EQU $85 ATDSTAT0 EQU $86 ; A/D status register (SCF) ATDSTAT1 EQU $87 ; A/D status register (CCF) *************************************************************** *ADC Results Registers* ADR0H EQU $90 ; 10 bit values take ADR0L EQU $91 ; 2 bytes of storage ADR1H EQU $92 ; Left justified have MSB ADR1L EQU $93 ; in high byte, bits 1,0 are ADR2H EQU $94 ; stored in b7,6 of low byte ADR2L EQU $95 ; ADR3H EQU $96 ; Right justified have LSB ADR3L EQU $97 ; stored in low byte, bits 9,8 ADR4H EQU $98 ; stored in b1,0 of high byte. ADR4L EQU $99 ; ADR5H EQU $9A ; 8 bit values ADR5L EQU $9B ; Left justified ADR6H EQU $9C ; stored in high bytes. ADR6L EQU $9D ; Right justified ADR7H EQU $9E ; stored in low bytes ADR7L EQU $9F ; of result registers. *************************************************************** *ATDCL2 Register Control Bits* *All bits are clear on reset* ADPU EQU %10000000 ; A/D power up bit, Set to power up AFFC EQU %01000000 ; Set to Fast Clear all CCF flags AWAI EQU %00100000 ; Set to power down A/D in wait mode ETRIGE EQU %00000100 ; Set to Enable external trigger ETRIGLE EQU %00010000 ; Set to Level Triggered (Clear for Edge) ETRIGP EQU %00001000 ; Set for Rising Edge or High Level ASCIE EQU %00000010 ; Set to enable ATD interrupt ASCIF EQU %00000001 ; Set by ATD when interrupt conversion complete *If AFFC is cleared then the CCF flag is reset only when* *ATDSTAT1 and the A/D results register(s) are read.* *If AFFC is set then the SCF flag is reset only when* *conversion sequence has completed and results read* *ASCIF is read only *************************************************************** *ATDCTL3 Register Control Bits *SC EQU %0xxxx 000 ; # of conversions in sequence, 1 to 8 (4 bits) FIFOATD EQU %00000100 ; Set to wrap around conversion results SC EQU %00001000 ; one conversion *************************************************************** *ATDCL4 Register Control Bits *Reset value is$05 (prescalar bits)* SRES8 EQU %10000000 ; Resolution, Set = 8 bit SMP EQU %01100000 ; SMP1 and SMP0 Sample Time Bits *PRS EQU %000xxxxx ; PRS Clock Prescalar Bits PRS EQU %00010111 ; PRS bits for this program *default resolution is 10 bits* *************************************************************** *ATDCL5 Register Control Bits* *All bits are clear on reset* JUSTIFY EQU %10000000 ; Set for right justification SIGN EQU %01000000 ; Set for signed number representation SCAN EQU %00100000 ; Set for continuous conversions MULT EQU %00010000 ; Set to sample multiple channels *AN EQU %00000xxx ; ATD Input Channel Number 0 to 7 (3 bit number) AN EQU %00000111 ; Using channel 7 for this program *************************************************************** *ATD Status Register 0 (ATDSTAT0)* *All bits are clear on reset* *The values of these constants are AND'd with ATDSTAT0. If the *result is non-zero, then the flag is set. If the result is zero then *the flag was not set by the ATD* SCF EQU %10000000 ; Sequence conversion Complete Flag ETORF EQU %00100000 ; Ext Trigger Overrun Flag FIFOR EQU %00010000 ; FIFO Overrun Flag *CC EQU %00000xxx ; 3 bit Conversion Counter (R only) *Writing a 1 to the SCF clears it* *FIFO indicates a register has been overwritten before* *it has been read.* *CC points to the next register to be used by the ATD* *************************************************************** *ATD Status Register 1 (ATDSTAT1)* *All bits are clear on reset* *CCF is used in a similar manner to the flags of ATDSTAT0 CCF EQU %11111111 ; Set by ATD for each results register *after it receives a value, if AFFC=0 reading ATDSTA1 and then* *a results register clears a CCF flag for each individual results register* *All cleared by a write to ATDCTL5* *If AFFC=1 a zero in a CCF bit indicates conversion number x has* *not completed.* *************************************************************** * Memory Map Equates *************************************************************** ;CODE EQU $1000 ;DATA EQU $1050 ;STACK EQU $3000 ; Remember that debug uses memory. ;DDRB EQU $0003 ;PORTB EQU $0001 *************************************************************** org CODE lds #STACK ldab #$FF ; Load B with %11111111 stab DDRB ; Makes portb an output port. clrb ; Clears acc. B ; Power up the A/D bset ATDCTL2 ADPU ; OR function, wakes up ADC. ; Generate a "short" delay > ? microsec to let ADC settle. ldaa #$FF ; FF loops for. short: nop ; 2 times FF loops dbne a,short ; Decriment acc. A and branch to delay. ; Now set up the A/D. ; Normal flag clearing, run in WAIT mode, no interrupts. bclr ATDCTL2 AFFC|AWAI|ASCIE|ETRIGE ; Clrears all the positions stated ; on the ATDCLT2. ; Mask bits are inverted and AND'd with ATDCTL2. ; Any mask bit that is a '1' clears the corresponding bit in ATDCTL2. Here we clear four bits. bclr ATDCTL3 #$FF ; Clear all bits bset ATDCTL3 SC ; 1 conversion needed for an7 ; The bus speed is 24 MHz. To obtain the slowest conversion time select the longest sample time ; and an ATD conversion clock frequency of 500kHz. Sample time: SMP1:SMP2 = 1:1 ; PRS = 10111, gives ATD ccf of 500kHz Conversion time = 32uS. bclr ATDCTL4 #$FF ; Clears ATDCLT4 and makes it ready for bit setting. bset ATDCTL4 #$60 ; Select 16 X sample time. bset ATDCTL4 PRS ; Set PRS, Divide 24 MHz by 48. bset ATDCTL4 SRES8 ; Use 8-bit conversion mode. ; Start the conversion by writing the scan select information to ATDCTL5. ; First change the ATD mode. top: bset ADMODE JUSTIFY ; Set %10000000 in ADMODE. bset ADMODE AN ; Set %00000111 in ADMODE. ldaa ADMODE ; Load acc. A with ADMODE. bclr ATDCTL5 #$FF ; Clear ATDCLT5 with the inverted valve of #$FF. staa ATDCTL5 ; Starts conversion. ; And wait until conversion done. spin: brclr ATDSTAT0 SCF, spin ; A bitwise AND. ; So that as long as SCF = 0, the branch to 'spin' is taken. ; When the SCF flag in ATDSTAT = 1 the branch is not taken! clrb ; Clear acc. B ldab ADR0L ; Load acc. B with the voltage value that is on the ; board that is stored in ADR0L. stab PORTB ; Show the voltage value with the LED'S. bsr longdelay bra top swi ; Stop the program and look at the values. org code ADMODE db $0 longdelay ldx #$ffff ldy #$0188 time: dbne x, time dbne y, time rts ;Stepper Motor Controller ; The Diodes on Port B Represent Stepper Motor Control Transistors PORTB equ $0001 ;Port B register DDRB equ $0003 ;Port B Data Direction Register PORTP equ $0258 ;Port P register DDRP equ $025A ;Port P Data Direction Register RDRP equ $025B ;Port P Reduced Drive Register DELAY equ $0002 ;$ffff ;Delay for software timing loops COUNTNUM equ 48 ;number of times to repeat CW direction CODE equ $1000 STACK equ $2000 ;STACK org CODE lds #STACK movb #$ff,DDRB ;make Port B all outputs movb #$00,PORTB ;clear Port B movb #$0f,DDRP ;make lower 4 bits Port P outputs movb #$00,PORTP ;clear Port P ldaa #COUNTNUM ;# of times to repeat CW direction staa count ;save count loop_CW jsr DelayM jsr Step_CW ;Step once CW (increment) ldaa Output_pattern ;load output pattern, setup by Step_CW staa PORTB ;output the pattern to diodes anda #$0F staa PORTP ;output the pattern to motor dec count bne loop_CW ;continue CW direction ldaa #COUNTNUM ;# of times to repeat CCW direction staa count loop_CCW jsr DelayM jsr Step_CCW ;Step once CCW (decrement) ldaa Output_pattern ;load output pattern, setup by Step_CCW staa PORTB ;output the pattern to diodes anda #$0F ;mask out upper 4 bits staa PORTP ;output the pattern to motor dec count bne loop_CCW ;continue CCW direction swi ;stop ;loop bra loop *************************************************** * * Step Clockwise Subroutine * * This subroutine controls clockwise rotation of the motors. * * Inputs: None * * Outputs: Ouput_pattern Modifies output pattern * Sequence_ptr Pointer to table of stepper commands * * Invokes: Nothing * *************************************************** Step_CW ldab Sequence_ptr ;Load Sequence pointer incb ;Increment to point to next * ;sequence value andb #$07 ;Restrict table addresses to lower 3 bits stab Sequence_ptr ;Save Sequence pointer clra ;Clear acc A addd #Step_Table ;Add address of Step Table xgdy ;Exchange D with Y so that * ;indirect addressing can be * ;performed again. ldab 0,y ;Load value from table stab Output_pattern ;Save output pattern rts ;Return *************************************************** * * Step Counter-Clockwise Subroutine * * This subroutine controls counter-clockwise rotation of the motors. * * Inputs: None * * Outputs: Output_pattern Modifies output pattern * Sequence_ptr Pointer to table of stepper commands * * Invokes: Nothing * *************************************************** Step_CCW ldab Sequence_ptr ;Load Sequence pointer decb ;Decrement to point to next * ;sequence value andb #$07 ;Keep lowest two bits stab Sequence_ptr ;Save Sequence pointer clra ;Clear acc A addd #Step_Table ;Add address of Step Table xgdy ;Exchange D with Y so that * ;indirect addressing can be * ;performed again. ldab 0,y ;Load value from table stab Output_pattern ;Save output pattern rts ;Return *************************************************** DelayM ldx #8 ;Have to delay so that mechanical motors ldy #$FFFF L1 dey bne L1 ;can keep up. dex bne L1 rts *************************************************** * * Step Table: * * This table contains the sequence to be output to cause the stepper * motors to turn. If followed from top to bottom, restarting the * sequence at the top when necessary, will cause the steppers to turn * clockwise. Following the sequence from bottom to top, restarting * the sequence at the bottom when necessary, the motors will turn * counter-clockwise. * *************************************************** org $1400 Step_Table * Full Step One Phase On dc.b $11 ;R dc.b $44 ;R dc.b $22 ;L dc.b $88 ;L ;*Full Step Two Phases On ;* dc.b $66 ; * dc.b $AA ; * dc.b $99 ; * dc.b $55 ; HalfStep dc.b $11 dc.b $55 dc.b $44 dc.b $66 dc.b $22 dc.b $AA dc.b $88 dc.b $99 count dc.b $00 ;Counts # of iterations Sequence_ptr dc.b $00 ;pointer to sequence to control motor Output_pattern dc.b $00 ;Pattern to output to port which ;controls the stepper motor board -----Original Message----- From: Jackie Johnson [mailto:] Sent: Thursday, March 25, 2004 8:52 AM To: ' Subject: Stepper Motors using the 68HC12 I have enclosed a program that I a working on and am trying to get this program to work properly. My motor is not stopping. Example: If I want my motor to stop at 90 degrees with a 1.2498 voltage applied via the POT (potentiometer). My motor is continually running and not stopping based on my POT adjustments. Any ideas would be greatly appreciated from a frustrated student, who is on Spring break and NOT in Mexico! I have enclosed my program (MINIIDE) for your perusal. I want to operate in the half-step mode. THANKS, Jackie --------------------To learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu o learn more about Motorola Microcontrollers, please visit http://www.motorola.com/mcu ---- -- Yahoo! Groups Links a.. To |
