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hi guys, just completed my pwm motor control program, please have look and see if there is any obvious mistakes, it was written on mplab uses special instruction mnemonics so probably only looks correct in mplab. it works ok but the frequency a bit low. gives reasonable output range about 5% to 96% of vdd. any advice on improving appreciated. best regards shaun ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; ;;; ;;; ANALOGUE INPUT AN0 ;;; ;;; PWM OUTPUT ON GP1 ;;; ;;; TO "H" BRIDGE MOTOR DRIVER ;;; ;;; WRITTEN BY SHAUN COLLIER ;;; ;;; 09-08- 03 ;;; ;;; 1K POT AND 100 OHM RESISTOR ;;; ;;; USED AS POTENTIAL DIVIDER ;;; ;;; TO GIVE 0.5V TO 2.9V ON AN0 ;;; ;;; STEADY 960 Hz ;;; ;;; BOTTOM OF H BRIDGE RANGE ;;; ;;; ;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; LIST PF675, RIMAL #INCLUDE <P12F675.INC> ERRORLEVEL -302 ;MICROCHIP RECOMMENDED (KNOWN BUG) ;CONFIG SETTINGS ;CODE PROTECTION DISABLED ;WATCHDOG TIMER DISABLED ;MASTER CLEAR INTERNAL ENABLED ;POWER UP TIMER DISABLED ;BROWN OUT DETECT DISABLED ;INTERNAL RC OSCILLATOR ENABLED 4Mhz __CONFIG _CP_OFF & _WDT_OFF & _MCLRE_OFF & _PWRTE_OFF &_BODEN_OFF & _INTRC_OSC_NOCLKOUT ORG 000 GOTO MAIN ;EQUATES TABLE DELAY_TIMER EQU 0X20 PWM_TIMER EQU 0X21 PWM_CYCLE EQU 0X22 ON EQU 0X23 OFF EQU 0X24 DELAY MOVLW 25 MOVWF DELAY_TIMER DECFSZ DELAY_TIMER,F GOTO $-1 RETURN INITIALISE_AD ;INITIALISES THE A/D CONVERSION MODULE BANKSEL TRISIO ;BANK 1 MOVLW B'00001001' ;MAKE GPIO,0 INPUT, GPIO,3 INPUT ONLY MOVWF TRISIO BSF PIE1,ADIE ;BANK 1 ;PERIPHERAL INTERUPT ENABLE ;A/D INTERUPT, 1=ENABLE, 0=DISABLE MOVLW B'01110001' MOVWF ANSEL ;BANK 1 ;ANALOG SELECT REGISTER ;BIT 7, UNIMPLEMENTED ;BITS 6-4, A/D CONVERSION CLOCK SELECT, x11=FRC, DEDICATED INTERNAL CLOCK, 500KHz MAX ;BITS 3-0, ANALOG SELECT BITS, 0=DIGITAL OR SPECIAL FUNCTIONS, 1=ANALOG INPUT BANKSEL ADCON0 MOVLW B'00000001' MOVWF ADCON0 ;BANK 0 ;BIT 7, ADFM, A/D RESULT JUSTIFICATION, 0=LEFT, 1=RIGHT ;BIT 6, VCFG, VOLTAGE REF, 0=Vdd, 1=EXTERNAL REF ;BITS 5-4, UNIMPLEMENTED ;BITS 3-2, ANALOG CHANNEL SELECT 00=AN0,01=AN1,10=AN2,11=AN3 ;BIT 1, GO_DONE, A/D STATUS BIT, 1=START AQUISITION, AUTOMATICALLY CLEARED WHEN FINISHED ;BIT 0, A/D CONVERSION STATUS, 1=A/D ON, 0=A/D OFF BSF INTCON,PEIE ;BANK 0 ;INTERUPT CONTROL REGISTER ;PERIPHERAL INTERUPT ENABLE,1=ENABLES UNMASKED INTERUPTS, 0=DISABLED BCF PIR1,ADIF ;A/D CONVERSION COMPLETE FLAG, 1=COMPLETE, 0=INCOMPLETE, MUST CLEARED IN SOFTWARE CALL DELAY ;TIME PERIOD REQUIRED TO ACQUIRE SIGNAL RETURN INITIALISE_DIGITAL BANKSEL TRISIO CLRF TRISIO ;CLEAR PORT DIRECTION REG BANKSEL PIE1 ;CLEAR PERIPHERAL INTERUPT ENABLE CLRF PIE1 BANKSEL ADCON0 CLRF ADCON0 ;CLEAR ANALOGUE CONFIG REG MOVLW 0x07 BANKSEL CMCON MOVWF CMCON ;SWITCH OFF COMPARATOR BANKSEL ANSEL CLRF ANSEL ;SWITCH ALL ANALOGUES OFF RETURN OUTPUT MOVLW 255 ;PWM TIME PERIOD MOVWF PWM_CYCLE CLRF OFF ;CLEAR OFF TIMER CLRF ON ;CLEAR PULSE PERIOD TIMER BANKSEL ADRESH MOVFW ADRESH ;MOVE MSB'S ANALOGUE INPUT INTO W REG MOVWF OFF ;MOVE ANALOGUE INTO OFF REGISTER NEGF OFF,W ;COMPLEMENT AND INCREMENT, SAVE BACK IN FILE MOVFW OFF ;MOVE NEGATIVE ANALOGUE INTO W REG ADDWF PWM_CYCLE,W ;ADD TO PWM TIME PERIOD TO GAIN OFF TIME MOVWF OFF INCF OFF,F ;INCREMENT TO ENSURE NO ROLL OVER BANKSEL GPIO BCF GPIO,1 ;ENSURE PULSE OFF MOVFW OFF MOVWF PWM_TIMER DECFSZ PWM_TIMER,F ;COUNTDOWN OFF PERIOD GOTO $-1 BANKSEL GPIO BSF GPIO,1 ;SWITCH PULSE ON BANKSEL ADRESH MOVFW ADRESH ;MOVWF ON ;MOVFW ON BANKSEL PWM_TIMER MOVWF PWM_TIMER INCF PWM_TIMER,F ;INCREMENT TO ENSURE NO ROLL OVER DECFSZ PWM_TIMER,F GOTO $-1 BCF GPIO,1 ;SWITCH PULSE OFF RETURN MAIN CALL INITIALISE_AD ;SWITCH A/D MODULE ON AND CONFIGURE BANKSEL ADCON0 BSF ADCON0,GO ;START CONVERSION OF ACQUIRED ANALOGUE SIGNAL BTFSC ADCON0,GO ;TEST TILL CONVERSION FINISHED THEN SKIP GOTO $-1 CALL INITIALISE_DIGITAL ;SWITCH ANALOGUE A/D MODULE OFF CALL OUTPUT ;PWM ROUTINE GOTO MAIN ;KEEP ON GOING END |