PWM on PIC16F88

[peterdeco1]

Hello Everyone. I am migrating from a 16F819 to a 16F88 for more codespace. I've used the HPWM command on the 16F818 without any problems. I've adjusted the top of the code to try making the 16F88 have the PWM output on portb.3 but it always comes out on portb.0 regardless of my DEFINE statement. Does anyone know what I'm doing wrong? Thank you.

OSCCON = $60 'set int osc to 4mhz
ANSEL = 0 'all inputs digital
TRISA = %11111111
TRISB = 0
PORTB = 0
@ DEVICE MCLR_OFF, INTRC_OSC, WDT_ON, LVP_OFF, BOD_OFF, PWRT_ON, PROTECT_ON
DEFINE CCP1_BIT 3 ' TRYING TO GET PWM ON RB3. IT DOES WORK BUT 'ALWAYS COMES OUT OF RB0
Pause 500

START:
CCP1CON = 0 'TURN OFF PWM
NAP 4
IF PORTA.1 = 0 Then blah blah '

GoTo START

[Melanie]

If you followed the instructions in this thread...

http://www.picbasic.co.uk/forum/showthread.php?t=543

You would have discovered you needed CCPMX_OFF somewhere in your @ DEVICE statement.

If using MPASM you would have needed _CCP1_RB3 in your config definitions.

The clue is in the fact that this is a CONFIGURATION WORD (CONFIG FUSE) setting (see PICs Datasheet) therefore you need to make those changes in your CONFIG Definitions which are burnt into the chip at Program Time.

[peterdeco1]

Thanks Melanie but it still doesn't work. My programmer gives me the option to change CCP1 ports on the F818 but not the F88. I spent hours changing the code but the HPWM command always comes out on RB0.

@ DEVICE MCLR_OFF, INTRC_OSC, WDT_ON, LVP_OFF, BOD_OFF, PWRT_ON, PROTECT_ON, CCPMX_OFF
DEFINE CCP1_BIT 3 ' ***IT'S STILL ON RB0

It compiles without errors but RB0 still outputs the PWM. HELP!! The PC Board pattern will allow the use of RB3 perfectly. If I HAVE to use RB0, I have to cut traces & solder jumper wires. Thank you.

[Melanie]

If your programmer does not give you full control of your Configuration Word for the 16F88, you must get back to the vendor that produced your programmer software for an update, or buy a new programmer, or call a friend who has the facility on theirs, or buy a few crates of beer (most problems dissappear after the first crate)...

[peterdeco1]

I guess I have to settle for PWM on RB0. No matter what I do, I can't enable RB3. Now I have 2 new things on my "to do" list. 1 - update my programmer, 2 - buy a case of Budweiser.

[mister_e]

well the Beer option may help or not... What about if you use the MPASM assembler instead of PM?
Look at the 16F88.INC file..

;================================================= =========================
;
; Configuration Bits
;
;================================================= =========================

_CONFIG1 EQU H'2007'
_CONFIG2 EQU H'2008'

;Configuration Byte 1 Options
_CP_ALL EQU H'1FFF'
_CP_OFF EQU H'3FFF'
_CCP1_RB0 EQU H'3FFF'
_CCP1_RB3 EQU H'2FFF'
_DEBUG_OFF EQU H'3FFF'
_DEBUG_ON EQU H'37FF'
_WRT_PROTECT_OFF EQU H'3FFF' ;No program memory write protection
_WRT_PROTECT_256 EQU H'3DFF' ;First 256 program memory protected
_WRT_PROTECT_2048 EQU H'3BFF' ;First 2048 program memory protected
_WRT_PROTECT_ALL EQU H'39FF' ;All of program memory protected
_CPD_ON EQU H'3EFF'
_CPD_OFF EQU H'3FFF'
_LVP_ON EQU H'3FFF'
_LVP_OFF EQU H'3F7F'
_BODEN_ON EQU H'3FFF'
_BODEN_OFF EQU H'3FBF'
_MCLR_ON EQU H'3FFF'
_MCLR_OFF EQU H'3FDF'
_PWRTE_OFF EQU H'3FFF'
_PWRTE_ON EQU H'3FF7'
_WDT_ON EQU H'3FFF'
_WDT_OFF EQU H'3FFB'
_EXTRC_CLKOUT EQU H'3FFF'
_EXTRC_IO EQU H'3FFE'
_INTRC_CLKOUT EQU H'3FFD'
_INTRC_IO EQU H'3FFC'
_EXTCLK EQU H'3FEF'
_HS_OSC EQU H'3FEE'
_XT_OSC EQU H'3FED'
_LP_OSC EQU H'3FEC'

;Configuration Byte 2 Options
_IESO_ON EQU H'3FFF'
_IESO_OFF EQU H'3FFD'
_FCMEN_ON EQU H'3FFF'
_FCMEN_OFF EQU H'3FFE'

so you must use the following line... written AS IS

@ __CONFIG _CONFIG1, _CCP1_RB3 & _DEBUG_OFF & _LVP_OFF & _BODEN_ON & _MCLR_OFF & _PWRTE_ON & _WDT_ON & _INTRC_IO

NOW, what about something like

@ __CONFIG _CONFIG1, _CCP1_RB3 & _DEBUG_OFF & _LVP_OFF & _BODEN_ON & _MCLR_OFF & _PWRTE_ON & _WDT_ON & _INTRC_IO
OSCCON=$60 ' use internal 4MHZ osc
PAUSE 100 ' start-up delay
TRISB=0
DEFINE CCP1_REG PORTB 
DEFINE CCP1_BIT 3 
HPWM 1,1000,128
HERE: GOTO HERE

Maybe you'll have the same results... maybe not. Keep us inform.