;********************************************************************** ;* * ;* Software License Agreement * ;* * ;* The software supplied herewith by Microchip Technology * ;* Incorporated (the "Company") is intended and supplied to you, the * ;* Company’s customer, for use solely and exclusively on Microchip * ;* 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: snsrless.asm * ; Date: 14 Jan 2002 * ; File Version: 1.0 * ; * ; Author: W.R.Brown * ; Company: Microchip Technolgy Incorporated * ; * ; * ;********************************************************************** ; * ; Files required: p16f877.inc * ; * ; * ; * ;********************************************************************** ; * ; Notes: Sensorless brushless motor control * ; * ; Closed loop 3 phase brushless DC motor control. * ; Two potentiometers control operation. One potentiometer (A0) * ; controls PWM (voltage) and RPM (from table). The other * ; potentiometer (A1) provides a PWM offset to the PWM derived * ; from A0. Phase A motor terminal is connected via voltage * ; divider to A3. This is read while the drive is on during * ; phase 4. The result is the peak applied voltage (Vsupply). * ; A3 is also read while the drive is on at two times during * ; phase 5. The result is the BEMF voltage. The BEMF voltage is * ; read at the quarter (t1) and mid (t2) points of the phase 5 * ; period. BEMF is compared to VSupply/2. If BEMF is above * ; VSupply/2 at t1 and below VSupply/2w at t2 then no speed * ; adjustment is made. If BEMF is high at both t1 and t2 then * ; the speed is reduced. If BEMF is low at t1 and t2 then the * ; speed is increased. * ; * ;********************************************************************** ; list P = PIC16F877 include "p16f877.inc" __CONFIG _CP_OFF & _WRT_ENABLE_OFF & _HS_OSC & _WDT_OFF & _PWRTE_ON & _BODEN_ON ; Acceleration/Deceleration Time = RampRate * 256 * 256 * Timer 0 prescale / Fosc #define AccelDelay D'255' ; determines full range acceleration time #define DecelDelay D'200' ; determines full range deceleration time #define ManThresh 0x3f ; Manual threshold is the PWM potentiomenter ; reading above which RPM is adjusted automatically #define AutoThresh 0x100-ManThresh OffMask equ B'11010101' ; PWM off kills the high drives Invalid equ B'00000000' ; invalid Phase1 equ B'00100001' ; phase 1 C high, A low Phase2 equ B'00100100' ; phase 2 C high, B low Phase3 equ B'00000110' ; phase 3 A high, B low Phase4 equ B'00010010' ; phase 4 A high, C low Phase5 equ B'00011000' ; phase 5 B high, C low Phase6 equ B'00001001' ; phase 6 B high, A low #define CARRY STATUS,C #define ZERO STATUS,Z #define subwl sublw ;********************************************************************************* ;* ;* Define I/O Ports ;* #define ReadIndicator PORTB,0 ; diagnostic scope trigger for BEMF readings #define DrivePort PORTC ; motor drive and lock status ;********************************************************************************* ;* ;* Define RAM variables ;* CBLOCK 0x20 STATE ; Machine state PWMThresh ; PWM threshold PhaseIndx ; Current motor phase index Drive ; Motor drive word RPMIndex ; RPM Index workspace ADCRPM ; ADC RPM value ADCOffset ; Delta offset to ADC PWM threshold PresetHi ; speed control timer compare MS byte PresetLo ; speed control timer compare LS byte Flags ; general purpose flags Vsupply ; Supply voltage ADC reading DeltaV1 ; Difference between expected and actual BEMF at T/4 DeltaV2 ; Difference between expected and actual BEMF at T/2 CCPSaveH ; Storage for phase time when finding DeltaV CCPSaveL ; Storage for phase time when finding DeltaV CCPT2H ; Workspace for determining T/2 and T/4 CCPT2L ; Workspace for determining T/2 and T/4 RampTimer ; Timer 0 post scaler for accel/decel ramp rate xCount ; general purpose counter workspace Status ; relative speed indicator status ENDC ;********************************************************************************* ;* ;* Define Flags ;* #define DriveOnFlag Flags,0 ; Flag for invoking drive disable mask when clear #define AutoRPM Flags,1 ; RPM timer is adjusted automatically ; Flags,3 ; Undefined #define FullOnFlag Flags,4 ; PWM threshold is set to maximum drive #define Tmr0Ovf Flags,5 ; Timer 0 overflow flag #define Tmr0Sync Flags,6 ; Second Timer 0 overflow flag ; Flags,7 ; undefined #define BEMF1Low DeltaV1,7 ; BEMF1 is low if DeltaV1 is negative #define BEMF2Low DeltaV2,7 ; BEMF2 is low if DeltaV2 is negative ;********************************************************************************* ;* ;* Define State machine states and index numbers ;* sRPMSetup equ D'0' ; Wait for Phase1, Set ADC GO, RA1->ADC sRPMRead equ sRPMSetup+1 ; Wait for ADC nDONE, Read ADC->RPM sOffsetSetup equ sRPMRead+1 ; Wait for Phase2, Set ADC GO, RA3->ADC sOffsetRead equ sOffsetSetup+1 ; Wait for ADC nDONE, Read ADC->ADCOffset sVSetup equ sOffsetRead+1 ; Wait for Phase4, Drive On, wait 9 uSec, Set ADC GO sVIdle equ sVSetup+1 ; Wait for Drive On, wait Tacq, set ADC GO sVRead equ sVIdle+1 ; Wait for ADC nDONE, Read ADC->Vsupply sBEMFSetup equ sVRead+1 ; Wait for Phase5, set Timer1 compare to half phase time sBEMFIdle equ sBEMFSetup+1 ; Wait for Timer1 compare, Force Drive on and wait 9 uSec, ; Set ADC GO, RA0->ADC sBEMFRead equ sBEMFIdle+1 ; Wait for ADC nDONE, Read ADC->Vbemf sBEMF2Idle equ sBEMFRead+1 ; Wait for Timer1 compare, Force Drive on and wait 9 uSec, ; Set ADC GO, RA0->ADC sBEMF2Read equ sBEMF2Idle+1 ; Wait for ADC nDONE, Read ADC->Vbemf ;********************************************************************************* ;* ;* The ADC input is changed depending on the STATE ;* Each STATE assumes a previous input selection and changes the selection ;* by XORing the control register with the appropriate ADC input change mask ;* defined here: ;* ADC0to1 equ B'00001000' ; changes ADCON0<5:3> from 000 to 001 ADC1to3 equ B'00010000' ; changes ADCON0<5:3> from 001 to 011 ADC3to0 equ B'00011000' ; changes ADCON0<5:3> from 011 to 000 ;********************************************************************************* ;**************************** PROGRAM STARTS HERE ******************************** ;********************************************************************************* org 0x000 nop goto Initialize org 0x004 bsf Tmr0Ovf ; Timer 0 overflow flag used by accel/decel timer bsf Tmr0Sync ; Timer 0 overflow flag used to synchronize code execution bcf INTCON,T0IF retfie ; Initialize clrf PORTC ; all drivers off clrf PORTB banksel TRISA ; setup I/O clrf TRISC ; motor drivers on PORTC movlw B'00001011' ; A/D on RA0 (PWM), RA1 (Speed) and RA3 (BEMF) movwf TRISA ; movlw B'11111110' ; RB0 is locked indicator movwf TRISB ; setup Timer0 movlw B'11010000' ; Timer0: Fosc, 1:2 movwf OPTION_REG bsf INTCON,T0IE ; enable timer 0 interrupts ; Setup ADC movlw B'00000100' ; ADC left justified, AN0, AN1 movwf ADCON1 banksel PORTA movlw B'10000001' ; ADC clk = Fosc/32, AN0, ADC on movwf ADCON0 ; setup Timer 1 movlw B'00100001' ; 1:4 prescale, internal clock, timer on movwf T1CON ; setup Timer 1 compare movlw 0xFF ; set compare to maximum count movwf CCPR1L ; LS compare register movwf CCPR1H ; MS compare register movlw B'00001011' ; Timer 1 compare mode, special event - clears timer1 movwf CCP1CON ; initialize RAM clrf PWMThresh movlw D'6' movwf PhaseIndx clrf Flags clrf Status ; clrf STATE ; LoopIdle->STATE bcf INTCON,T0IF ; ensure timer 0 overflow flag is cleared bsf INTCON,GIE ; enable interrupts MainLoop ;***************************************************************** ; ; PWM, Commutation, State machine loop ; ;***************************************************************** btfsc PIR1,CCP1IF ; time for phase change? call Commutate ; yes - change motor drive PWM bsf DriveOnFlag ; pre-set flag btfsc FullOnFlag ; is PWM level at maximum? goto PWM02 ; yes - only commutation is necessary movf PWMThresh,w ; get PWM threshold addwf TMR0,w ; compare to timer 0 btfss CARRY ; drive is on if carry is set bcf DriveOnFlag ; timer has not reached threshold, disable drive call DriveMotor ; output drive word PWM02 call LockTest call StateMachine ; service state machine goto MainLoop ; repeat loop StateMachine movlw SMTableEnd-SMTable-1 ; STATE table must have 2^n entries andwf STATE,f ; limit STATE index to state table movlw high SMTable ; get high byte of table address movwf PCLATH ; prepare for computed goto movlw low SMTable ; get low byte of table address addwf STATE,w ; add STATE index to table root btfsc CARRY ; test for page change in table incf PCLATH,f ; page change adjust movwf PCL ; jump into table SMTable ; number of STATE table entries MUST be evenly divisible by 2 goto RPMSetup ; Wait for Phase1, Set ADC GO, RA1->ADC, clear timer0 overflow goto RPMRead ; Wait for ADC nDONE, Read ADC->RPM goto OffsetSetup ; Wait for Phase2, Set ADC GO, RA3->ADC goto OffsetRead ; Wait for ADC nDONE, Read ADC->ADCOffset goto VSetup ; Wait for Phase4 goto VIdle ; Wait for Drive On, wait Tacq, set ADC GO goto VRead ; Wait for ADC nDONE, Read ADC->Vsupply goto BEMFSetup ; Wait for Phase5, set Timer1 compare to half phase time goto BEMFIdle ; When Timer1 compares force Drive on, Set ADC GO after Tacq, RA0->ADC goto BEMFRead ; Wait for ADC nDONE, Read ADC->Vbemf goto BEMF2Idle ; When Timer1 compares force Drive on, Set ADC GO after Tacq, RA0->ADC goto BEMF2Read ; Wait for ADC nDONE, Read ADC->Vbemf ; fill out table with InvalidStates to make number of table entries evenly divisible by 2 goto InvalidState ; invalid state - reset state machine goto InvalidState ; invalid state - reset state machine goto InvalidState ; invalid state - reset state machine goto InvalidState ; invalid state - reset state machine SMTableEnd ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ RPMSetup ; Wait for Phase1, Set ADC GO, RA1->ADC, clear timer0 overflow movlw Phase1 ; compare Phase1 word... xorwf Drive,w ; ...with current drive word btfss ZERO ; ZERO if equal return ; not Phase1 - remain in current STATE bsf ADCON0,GO ; start ADC movlw ADC0to1 ; prepare to change ADC input xorwf ADCON0,f ; change from AN0 to AN1 incf STATE,f ; next STATE bcf Tmr0Sync ; clear timer0 overflow return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ RPMRead ; Wait for ADC nDONE, Read ADC->RPM btfsc ADCON0,GO ; is ADC conversion finished? return ; no - remain in current STATE movf ADRESH,w ; get ADC result movwf ADCRPM ; save in RPM incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ OffsetSetup ; Wait for Phase2, Set ADC GO, RA3->ADC movlw Phase2 ; compare Phase2 word... xorwf Drive,w ; ...with current drive word btfss ZERO ; ZERO if equal return ; not Phase2 - remain in current STATE bsf ADCON0,GO ; start ADC movlw ADC1to3 ; prepare to change ADC input xorwf ADCON0,f ; change from AN1 to AN3 incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ OffsetRead ; Wait for ADC nDONE, Read ADC->ADCOffset btfsc ADCON0,GO ; is ADC conversion finished? return ; no - remain in current STATE movf ADRESH,w ; get ADC result xorlw H'80' ; complement MSB for +/- offset movwf ADCOffset ; save in offset addwf ADCRPM,w ; add offset to PWM result btfss ADCOffset,7 ; is offset a negative number? goto OverflowTest ; no - test for overflow btfss CARRY ; underflow? andlw H'00' ; yes - force minimum goto Threshold ; OverflowTest btfsc CARRY ; overflow? movlw H'ff' ; yes - force maximum Threshold movwf PWMThresh ; PWM threshold is RPM result plus offset btfsc ZERO ; is drive off? goto DriveOff ; yes - skip voltage measurements bcf FullOnFlag ; pre-clear flag in preparation of compare sublw 0xFD ; full on threshold btfss CARRY ; CY = 0 if PWMThresh > FullOn bsf FullOnFlag ; set full on flag incf STATE,f ; next STATE return ; back to Main Loop DriveOff clrf Status ; clear speed indicators movlw B'11000111' ; reset ADC input to AN0 andwf ADCON0,f ; clrf STATE ; reset state machine return ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ VSetup ; Wait for Phase4 movlw Phase4 ; compare Phase4 word... xorwf Drive,w ; ...with current Phase drive word btfss ZERO ; ZERO if equal return ; not Phase4 - remain in current STATE call SetTimer ; set timer value from RPM table incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ VIdle ; Wait for Drive On, wait Tacq, set ADC GO btfss DriveOnFlag ; is Drive active? return ; no - remain in current STATE bsf ReadIndicator ; Diagnostic call Tacq ; motor Drive is active - wait ADC Tacq time bsf ADCON0,GO ; start ADC bcf ReadIndicator ; Diagnostic incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ VRead ; Wait for ADC nDONE, Read ADC->Vsupply btfsc ADCON0,GO ; is ADC conversion finished? return ; no - remain in current STATE movf ADRESH,w ; get ADC result movwf Vsupply ; save as supply voltage incf STATE,f ; next STATE bcf Tmr0Sync ; clear timer 0 overflow return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ BEMFSetup ; Wait for Phase5, set Timer1 compare to half phase time movlw Phase5 ; compare Phase5 word... xorwf Drive,w ; ...with current drive word btfss ZERO ; ZERO if equal return ; not Phase5 - remain in current STATE btfss Tmr0Sync ; synchronize with timer 0 return ; btfss PWMThresh,7 ; if PWMThresh > 0x80 then ON is longer than OFF goto BEMFS1 ; OFF is longer and motor is currently off - compute now btfss DriveOnFlag ; ON is longer - wait for drive cycle to start return ; not started - wait BEMFS1 bcf CCP1CON,0 ; disable special event on compare movf CCPR1H,w ; save current capture compare state movwf CCPSaveH ; movwf CCPT2H ; save copy in workspace movf CCPR1L,w ; low byte movwf CCPSaveL ; save movwf CCPT2L ; and save copy bcf CARRY ; pre-clear carry for rotate rrf CCPT2H,f ; divide phase time by 2 rrf CCPT2L,f ; bcf CARRY ; pre-clear carry rrf CCPT2H,w ; divide phase time by another 2 movwf CCPR1H ; first BEMF reading at phase T/4 rrf CCPT2L,w ; movwf CCPR1L ; incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ BEMFIdle ; When Timer1 compares force Drive on, Set ADC GO after Tacq, RA0->ADC btfss PIR1,CCP1IF ; timer compare? return ; no - remain in current STATE bsf DriveOnFlag ; force drive on for BEMF reading call DriveMotor ; activate motor drive bsf ReadIndicator ; Diagnostic call Tacq ; wait ADC acqisition time bsf ADCON0,GO ; start ADC bcf ReadIndicator ; Diagnostic ; setup to capture BEMF at phase 3/4 T movf CCPT2H,w addwf CCPR1H,f ; next compare at phase 3/4 T movf CCPT2L,w ; addwf CCPR1L,f ; set T/2 lsb btfsc CARRY ; test for carry into MSb incf CCPR1H,f ; perform carry bcf PIR1,CCP1IF ; clear timer compare interrupt flag incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ BEMFRead ; Wait for ADC nDONE, Read ADC->Vbemf btfsc ADCON0,GO ; is ADC conversion finished? return ; no - remain in current STATE rrf Vsupply,w ; divide supply voltage by 2 subwf ADRESH,w ; Vbemf - Vsupply/2 movwf DeltaV1 ; save error voltage incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ BEMF2Idle ; When Timer1 compares force Drive on, Set ADC GO after Tacq, RA0->ADC btfss PIR1,CCP1IF ; timer compare? return ; no - remain in current STATE bsf DriveOnFlag ; force drive on for BEMF reading call DriveMotor ; activate motor drive bsf ReadIndicator ; Diagnostic call Tacq ; wait ADC acqisition time bsf ADCON0,GO ; start ADC bcf ReadIndicator ; Diagnostic movlw ADC3to0 ; prepare to change ADC input xorwf ADCON0,f ; change from AN3 to AN0 ; restore Timer1 phase time and special event compare mode movf CCPSaveH,w movwf CCPR1H ; next compare at phase T movf CCPSaveL,w ; movwf CCPR1L ; set T lsb bcf PIR1,CCP1IF ; clear timer compare interrupt flag bsf CCP1CON,0 ; enable special event on compare incf STATE,f ; next STATE return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ BEMF2Read ; Wait for ADC nDONE, Read ADC->Vbemf btfsc ADCON0,GO ; is ADC conversion finished? return ; no - remain in current STATE rrf Vsupply,w ; divide supply voltage by 2 subwf ADRESH,w ; Vbemf - Vsupply/2 movwf DeltaV2 ; save error voltage clrf STATE ; reset state machine to beginning return ; back to Main Loop ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ InvalidState ; trap for invalid STATE index movlw B'11000111' ; reset ADC input to AN0 andwf ADCON0,f ; clrf STATE return ;______________________________________________________________________________________________________ Tacq ;***************************************************************** ; ; Software delay for ADC acquisition time ; Delay time = Tosc*(3+3*xCount) ; ;***************************************************************** movlw D'14' ; 14 equates to approx 9 uSec delay movwf xCount ; decfsz xCount,f ; goto $-1 ; loop here until time complete return LockTest ;***************************************************************** ; ; T is the commutation phase period. Back EMF is measured on the ; floating motor terminal at two times during T to determine ; the approximate zero crossing of the BEMF. BEMF low means that ; the measured BEMF is below (supply voltage)/2. ; If BEMF is low at 1/4 T then accelerate. ; If BEMF is high at 1/4 T and low at 3/4 T then speed is OK. ; If BEMF is high at 1/4 T and 3/4 T then decelerate. ; ; Lock test computation is synchronized to the PWM clock such ; that the computation is performed during the PWM ON or OFF ; time whichever is longer. ; ;***************************************************************** ; synchronize test with start of timer 0 btfss Tmr0Ovf ; has timer 0 wrapped around? return ; no - skip lock test btfss PWMThresh,7 ; if PWMThresh > 0x80 then ON is longer than OFF goto LT05 ; OFF is longer and motor is currently off - compute now btfss DriveOnFlag ; ON is longer - wait for drive cycle to start return ; not started - wait LT05 bcf Tmr0Ovf ; clear synchronization flag decfsz RampTimer,f ; RampTimer controls the acceleration/deceleration rate return ; use lock results to control RPM only if not manual mode bsf AutoRPM ; preset flag movf ADCRPM,w ; compare RPM potentiometer... addlw AutoThresh ; ...to the auto control threshold btfss CARRY ; CARRY is set if RPM is > auto threshold bcf AutoRPM ; not in auto range - reset flag btfss BEMF1Low ; is first BEMF below Supply/2 goto LT20 ; no - test second BEMF LT10 ; accelerate if BEMF at 1/4 T is below Supply/2 movlw B'10000000' ; indicate lock test results movwf Status ; status is OR'd with drive word later movlw AccelDelay ; set the timer for acceleration delay movwf RampTimer ; btfss AutoRPM ; is RPM in auto range? goto ManControl ; no - skip RPM adjustment incfsz RPMIndex,f ; increment the RPM table index return ; return if Index didn't wrap around decf RPMIndex,f ; top limit is 0xFF return LT20 btfsc BEMF2Low ; BEMF1 was high... goto ShowLocked ; ... and BEMF2 is low - show locked ; decelerate if BEMF at 3/4 T is above Supply/2 movlw B'01000000' ; indicate lock test results movwf Status ; status is OR'd with drive word later movlw DecelDelay ; set the timer for deceleration delay movwf RampTimer ; btfss AutoRPM ; is RPM in auto range? goto ManControl ; no - skip RPM adjustment decfsz RPMIndex,f ; set next lower RPM table index return ; return if index didn't wrap around incf RPMIndex,f ; bottom limit is 0x01 return ShowLocked movlw B'11000000' ; indicate lock test results movwf Status ; status is OR'd with drive word later movlw DecelDelay ; set the timer for deceleration delay movwf RampTimer ; btfsc AutoRPM ; was RPM set automatically? return ; yes - we're done ManControl movf ADCRPM,w ; get RPM potentiometer reading... movwf RPMIndex ; ...and set table index directly return Commutate ;***************************************************************** ; ; Commutation is triggered by PIR1 flag. ; This flag is set when timer1 equals the compare register. ; When BEMF measurement is active the compare time is not ; cleared automatically (special event trigger is off). ; Ignore the PIR1 flag when special trigger is off ; because the flag is for BEMF measurment. ; If BEMF measurement is not active then decrement phase table ; index and get the drive word from the table. Save the ; drive word in a global variable and output to motor drivers. ; ;***************************************************************** btfss CCP1CON,0 ; is special event on compare enabled? return ; no - this is a BEMF measurment, let state machine handle this bcf PIR1,CCP1IF ; clear interrupt flag movlw high OnTable ; set upper program counter bits movwf PCLATH decfsz PhaseIndx,w ; decrement to next phase goto $+2 ; skip reset if not zero movlw D'6' ; phase counts 6 to 1 movwf PhaseIndx ; save the phase index addlw LOW OnTable btfsc CARRY ; test for possible page boundry incf PCLATH,f ; page boundry adjust call GetDrive movwf Drive ; save motor drive word DriveMotor movf Drive,w ; restore motor drive word btfss DriveOnFlag ; test drive enable flag andlw OffMask ; kill high drive if PWM is off iorwf Status,w ; show speed indicators movwf DrivePort ; output to motor drivers return GetDrive movwf PCL ; computed goto OnTable retlw Invalid retlw Phase6 retlw Phase5 retlw Phase4 retlw Phase3 retlw Phase2 retlw Phase1 retlw Invalid SetTimer ;***************************************************************** ; ; This sets the CCP module compare registers for timer 1. ; The motor phase period is the time it takes timer 1 ; to count from 0 to the compare value. The CCP module ; is configured to clear timer 1 when the compare occurs. ; Get the timer1 compare variable from two lookup tables, one ; for the compare high byte and the other for the low byte. ; ;***************************************************************** call SetTimerHigh movwf CCPR1H ; Timer1 High byte preset call SetTimerLow movwf CCPR1L ; Timer1 Low byte preset return SetTimerHigh movlw high T1HighTable ; lookup preset values movwf PCLATH ; high bytes first movlw low T1HighTable ; addwf RPMIndex,w ; add table index btfsc STATUS,C ; test for table page crossing incf PCLATH,f ; movwf PCL ; lookup - result returned in W SetTimerLow movlw high T1LowTable ; repeat for lower byte movwf PCLATH ; movlw low T1LowTable ; addwf RPMIndex,w ; add table index btfsc STATUS,C ; test for table page crossing incf PCLATH,f ; movwf PCL ; lookup - result returned in W #include "BLDCspd4.inc" end