Newbie help: 16F690

[mbw123]

OK, I followed your link. I followed the instructions but there is a compile error stating that "undefined symbol: CMCON". Here is my new code:
----------------------------
CMCON = 7

main:

if PORTA.3 = 1 then pressed
goto main

pressed:
high PORTC.3
pause 250
low PORTC.3
Pause 250

goto main
-----------------------------

Any help is appreciated!

-Mike

[mister_e]

Sure it will never work as there's no CMCON register for that PIC. BTW internal comparator are disabled at POR. Your problem is more with the ADCs.

ANSEL=0 ' disable ADCs

[Darrel Taylor]

Ok, well I guess that wasn't the best advice for the chip you are using.

On a 16F690, PORTA.3 is the MCLR/VPP pin, and it defaults to the "Master Clear" (MCLR). In order to use it as a digital input, MCLR must be disabled.

If using PM as the assembler then use this...

@ DEVICE MCLR_OFF

or if using MPASM..

@  __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF

But you'll need to modify the 16F690.INC file in the PBP folder for it to work.

Also, PORTC.3 is multiplexed with the A/D converter, the Comparators, and the ECCP module. To use this pin as a digital output ...

ANSEL = 0
ANSELH = 0  ; for ANS8-11

The 16F690 is a very complex chip as far as PIC's go. And the datasheet is very confusing, to say the least. Wouldn't really recommend it for a first time user.

HTH,

P.S. Steve, I found the ANSELH from one of your previous posts.

[mister_e]

P.S. Steve, I found the ANSELH from one of your previous posts.

Hehe, was it the Ron Marcus Thread

It's an interesting PIC so far. I have few of them here but never found time to play with. mmm, this is why the Comparator latches reminded me something when surfing fast in the datasheet.

The 16F690 is a very complex chip as far as PIC's go. And the datasheet is very confusing, to say the least.

At least i'm not the only one to say that

[Darrel Taylor]

>> Hehe, was it the Ron Marcus Thread

PBP & 16F690 bug?
http://www.picbasic.co.uk/forum/show...ghlight=16F690

That's the one!

Saved me from another hour or two of searching through that awful datasheet.

Thanks!
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