PWM on PIC16F88

[peterdeco1]

Thanks Steve but I think Melanie is right - time for a lot of beer. Followed your code exactly and the PWM still comes out on RB0. Do you have any other ideas I can try when I get sober?

[mister_e]

i'll check that later tonight with my own stuff.

[mister_e]

well i just tried that one...

@ DEVICE MCLR_ON, INTRC_OSC, WDT_ON, LVP_OFF, BOD_OFF, PWRT_ON, PROTECT_OFF, CCPMX_ON
OSCCON=$60 ' use internal 4MHZ osc
PAUSE 100 ' start-up delay
TRISB=0
DEFINE CCP1_REG PORTB 
DEFINE CCP1_BIT 3 
HPWM 1,128,1000
HERE: GOTO HERE

no big difference on the previous,just correcting the way i wrote HPWM, enable the MCLR and remove CodeProtect... it's working on RB3 as it's suppose to.

BTW i'd attach the .HEX file to dump on your PIC. Let's assume that it could be a compiler problem... maybe.

let us know.

PS just rename .txt to .hex

[peterdeco1]

Hi Steve. I copied your code exactly and it still outputs only on RB0. I suspect my programmer and/or software is the problem. There is an option "CCP1 on RB3" that works on the 16F818 but the option is "grayed out" when I program the 16F88. I guess it will not allow the use of RB3. I think it's time to get the latest hardware/software from Microchip. Thank you for your help.

[peterdeco1]

That was it. My software was forcing CCP1 onto RB0, while MPLAB software shows "CCP1 ON RB3". Thanks Everybody.

[Dick Ivers]

peterdeco1,

What programmer software and hardware are you using that causes the problem? We would all like to know. We want to avoid running in to the same difficulties.

[ntege]

hi guys can any one help with assembly code for dimming an led using the pic16f88. ihave read the datasheet but i dont seem to underatand it i have come with code but it doesnt work can anybody tell me whats wrong with my code.


list p=16f88
INCLUDE "p16f88.inc"


_;****Set up the Constants****

STATUS equ 03h
TRISA equ 85h ;Address of the STATUS register
TRISB equ 86h
PORTA equ 05h ;Address of the tristate register for port A
PORTB equ 06h ;Address of Port A
COUNT1 equ 20h ;First counter for our delay loops
COUNT2 equ 21h ;Second counter for our delay loops
ANSEL equ 9Bh
OSCCON equ 8Fh
CCP1CON equ 17h
T2CON equ 12h
TMR2 equ 11h
CCPR1L equ 15h
PR2 equ 92h
PIR1 equ 0Ch
PIE1 equ 8Ch


movlw B'00000000' ; 31.25khz
bsf STATUS, 5
movwf OSCCON
nop
nop
nop
bcf STATUS, 5
movlw b'00111100'
movwf CCP1CON

bsf 03h,5 ;Go to Bank 1
movlw 00h ;Put 00000 into W
movwf TRISA ;Move 00000 onto TRISA – all pins set to output

movlw 00h ;Set the Port B pins
movwf TRISB ;to output. ;Put 00000 into W

movlw 00h
movwf ANSEL ;Move 00000 onto TRISA – all pins set to output

movlw b'11111111'
movwf PR2

bcf 03h,5 ;Come back to Bank 0
movlw b'00001111'
movwf TMR2



Start
movlw b'00001111'
movwf CCPR1L ; set duty cycle
Loop1
decfsz CCPR1L ;dimming led by varying the duty cycle
goto Loop1
goto Start
end