PIC 18F4431 Power PWM , i am lost! - Electronic Circuits Projects Diagrams Free

max_imum2000 · 17th May 2006, 07:26 PM

i am playing around with these 40pin pics .
i am trying to control three 12v DC motors (not steppers , not servo) over h-bridge, with no feedback.
the 18F4431 has power pwm module that comes build in to provide up to 8 channels in complemntry mode
however i read the datasheet on the power pwm module and cant understand how to work with this module easly.
i downloaded several application notes, but most of them are reffering to ccp pwm .
i will appricate any help or any step by step instruction on how to do that

thank you

motion · 18th May 2006, 12:57 PM

Here is a code snippet to initialize the PWM module. It is not yet been tested since I had set that project aside for now. I hope it helps you get started.

You define the value of PTPER_VAL to set the PWM frequency. See table 17-2 of the PIC18F4431 datasheet for the suggested values.

Code:

;-----------------------------------------------------------
;   Init PWM module
;
         MOVLW    1<<PTMOD1       ; 1:1 prescale,1:1 postscale, up/down
         MOVWF    PTCON0
;
         MOVLW    1<<PWMEN2|1<<PWMEN1|1<<PMOD1|1<<PMOD0
         MOVWF    PWMCON0
;
         MOVLW    0               ; 1:1 Postscale
         MOVWF    PWMCON1
;
         MOVLW    LOW  PTPER_VAL
         MOVWF    PTPERL
         MOVLW    HIGH PTPER_VAL
         MOVWF    PTPERH
;
         CLRF     DTCON
;
         BSF      PTCON1,PTEN     ; Fire up the PWM module

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17th May 2006, 07:26 PM	(permalink)
max_imum2000	PIC 18F4431 Power PWM , i am lost! i am playing around with these 40pin pics . i am trying to control three 12v DC motors (not steppers , not servo) over h-bridge, with no feedback. the 18F4431 has power pwm module that comes build in to provide up to 8 channels in complemntry mode however i read the datasheet on the power pwm module and cant understand how to work with this module easly. i downloaded several application notes, but most of them are reffering to ccp pwm . i will appricate any help or any step by step instruction on how to do that thank you

18th May 2006, 12:57 PM	(permalink)
motion	Here is a code snippet to initialize the PWM module. It is not yet been tested since I had set that project aside for now. I hope it helps you get started. You define the value of PTPER_VAL to set the PWM frequency. See table 17-2 of the PIC18F4431 datasheet for the suggested values. Code: ;----------------------------------------------------------- ; Init PWM module ; MOVLW 1<<PTMOD1 ; 1:1 prescale,1:1 postscale, up/down MOVWF PTCON0 ; MOVLW 1<<PWMEN2\|1<<PWMEN1\|1<<PMOD1\|1<<PMOD0 MOVWF PWMCON0 ; MOVLW 0 ; 1:1 Postscale MOVWF PWMCON1 ; MOVLW LOW PTPER_VAL MOVWF PTPERL MOVLW HIGH PTPER_VAL MOVWF PTPERH ; CLRF DTCON ; BSF PTCON1,PTEN ; Fire up the PWM module __________________ "Having to do with Motion Control"