PIC16F685 RA4/RA5 pins

[mackrackit]

Not sure I remember, but I think the comparators on that chip are under the
CM1CON0 and CM2CON0 registers. And A4 is open collector.
http://www.picbasic.co.uk/forum/showthread.php?t=562

You may want to look at the inc file in MPASM to be sure.

[Adrian]

Thanks mackrackit but still no joy. I've tried the open collector thing and I believe the COMCON0 to be right. This is puzzling me. I would have thought there should not be clock on A4 when INTOSCIO is chosen as a fuse. I'll keep trying (or change the PIC type.....!!!!)

Adrian

[Acetronics2]

Hi,

May be the underscore befre INTOSCIO ... ???

_EXTRC_OSC_NOCLKOUT EQU H'3FFE'
_EXTRC_OSC_CLKOUT EQU H'3FFF'
_INTOSCIO EQU H'3FFC'
_INTOSC EQU H'3FFD'
_EXTRCIO EQU H'3FFE'
_EXTRC EQU H'3FFF'

Beer for everyone !!!

Alain

[Bruce]

@_CONFIG INTOSCIO & _WDT_ON & MCRE_OFF & _CP_OFF ; 5 errors here
ANSEL = $00
OSCON = %01100001 ; 1 error here
CMCON0 = 7 ; 1 (maybe 2) errors here
TRISA = $00
TRISC = $00

First person to find them all gets the beer...;o}

[Adrian]

Hi Alain

Sadly not, so no beer - not even a good Cotes du Rhone from E.Guigal........! Unfortunately this was a typo error on my post. It was correct in the programme. Rest of programme is fine but RA4/RA5 stubbornly refuse to do anything useful. If someone out there has a 16F684 I'd like them to try it!

adrian

[Adrian]

Sorry for wrong information. This should be Pic16F684 not 685. Must be getting tired. HOWEVER it still doesn't work!!

[Adrian]

Hi Bruce

Working through the errors!

OSCCON is typo in my post - OK in programme
MCLRE ditto
underscore in INTOSCIO ditto
Can't see anything wrong with CMCON0Apologise for wrong PIC reference in post and typos
Still stuck

Adrian

[Adrian]

Hi Bruce

My programme is exactly the same as yours (I removed the 1 from OSCCON bit 0). It is just the same as before. I have a 1 Mhz square wave on pin 4 and a sawtooth waveform on pin 5. I have removed everything else in the programme now apart from a LED flashing on RA1. If I try to do that on RA4/RA5 - zilch. The relevant config line was commented out in the PBP pic inc file but I had also tried programming both ways with no luck.

[Bruce]

It would be a bit different if it's not a 685. Try something like this, and make sure your
device programmer keeps your config settings. You'll also need to comment out the default
config setting in the 16F684.INC file for MPASM.

@ __CONFIG _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF

ANSEL = $00
OSCCON = %01100000
CMCON0 = 7
TRISA = $00
TRISC = $00