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Maybe this is a stupid question, already answered before, but I could not find the answer...
I am trying to use PORTC of a PIC18F14K50 as outputs.
To do so, I use:
ANSEL = 0
ANSELH= 0
TRISC = 0
PORTC = 0
IMHO this should configure PORTC as digital and set the outputs of PORTC low.
But it seems I can still pull the pins easily to high, using a resistor.
This gives me the impression that the pins are still inputs!
What am I overlooking?
port c has comparator outputs i would set them to 0 as well
refer page 95-97 of data sheet , comparitor take priority over data i/o
Isn't that what I am doing with ANSEL and ANSELH ? Or am I still missing something?
This is register values that I used to turn off all analog stuff.
Code:REFCON0=0
REFCON1=0
ADCON1=0
ADCON2=0
ANSEL =0
ANSELH=0
CM1CON0=0
CM2CON0=0
SRCON0=0
SRCON1=0
WPUA=0
WPUB=0
Thanks! I will try that and report the results!
Mmm... I tried this but it still doesn't work!
Code:REFCON0=0
REFCON1=0
ADCON1=0
ADCON2=0
ANSEL =0
ANSELH=0
CM1CON0=0
CM2CON0=0
SRCON0=0
SRCON1=0
WPUA=0
WPUB=0
TRISC = 0
PORTC = 0
ProgStart:
PORTC.2 = 1
pause 1000
PORTC.2 = 0
pause 1000
goto ProgStart
Are you sure that problems are in portc?
Did you test other port? Maybe you didn't configure oscillator correct, or MCLR pin, etc...
Yes, when I use PORTB everything is fine!
(I can pull the C-outputs still high with a resistor. This gives me the impression that the pins are inputs.)
What value are resistor?
Try to put LED on portc with 1K series resistor, then see what is happening...
The result is (as expected): nothing!
PORTC is probably damaged...
You can try to use LAT registers, but...
I don't think so, because the result is the same with different (new!) 18F14K50's...Quote:
PORTC is probably damaged...
New test:
PORTC.3, C.6 and C.7 work, PORTC.0, C.1, C.2. C4 and C.5 don't...Code:REFCON0=0
REFCON1=0
ADCON1=0
ADCON2=0
ANSEL =0
ANSELH=0
CM1CON0=0
CM2CON0=0
SRCON0=0
SRCON1=0
WPUA=0
WPUB=0
TRISC = 0
PORTC = 0
ProgStart:
PORTC = 0
pause 1000
PORTC = 255
pause 1000
goto ProgStart
So... what's the common factor?
Hi,
I've been looking thru the datasheet to figure out what might be going on but I honestly can't find it.
So, I'm going to sugest that you might have a hardware issue, is this on a breadboard by any chance? Faulty contacts?
Going thru the datasheet I also noted the follwing regarding setting all those registers to 0 in your code:
REFCON0=0 (pg.247)
Defaults to 16 at POR which means that the FVR is set to 1.024V but disabled, setting it to 0 shouldn't be needed.
Instead, it specifically says not to use the value 0....
REFCON1=0 (pg.248)
Defaults to 0 at POR, DAC disabled, setting it to 0 shouldn't be needed.
ADCON1=0 (pg.216)
Defaults to 0 at POR, setting it to 0 shouldn't be needed.
ADCON2=0 (pg.217)
Defaults to 0 at POR, setting it to 0 shouldn't be needed.
ANSEL = 0 (pg.98)
Defaults to 248 at POR, setting it to 0 IS needed to enable the digital input buffers.
ANSELH = 0 (pg.99)
Defaults to 15 at POR, setting it to 0 IS needed to enable the digital input buffers.
CM1CON0=0 (pg.229)
Defaults to 0 at POR, comparator is disabled, setting it to 0 shouldn't be needed.
CM2CON0=0 (pg.230)
Defaults to 0 at POR, comparator is disabled, setting it to 0 shouldn't be needed.
SRCON0=0 (pg.242)
Defaults to 0 at POR, SR latch is disabled, setting it to 0 shouldn't be needed.
SRCON1=0 (pg.243)
Defaults to 0 at POR, SR latch is disabled, setting it to 0 shouldn't be needed.
WPUA=0 (pg.86)
Defaults to 56 at POR, PortA pulups enabled, setting it to 0 disables the pullups individually.
However, INTCON2.7 is the "master switch" PortA and PortB pullups and it defaults to 1 which means pullups are disabled.
So, if you're NOT clearing INTCON2.7 there shouldn't be any need to set WPUA=0
WPUB=0 (pg.91)
Defaults to 240 at POR, PortB pullups enabled, setting it to 0 disables the pullups individually.
However, INTCON2.7 is the "master switch" PortA and PortB pullups and defaults to 1 which means pullups are disabled.
So, if you're NOT clearing INTCON2.7 there shouldn't be any need to set WPUA=0
/Henrik.
Thank you Henrik for your time and effort.
I think you are right, setting states that are the same as after POR are not very useful...
I think I give up for today. Tomorrow there's an other day...
Have you tried AllDigital?
http://www.picbasic.co.uk/forum/showthread.php?t=11100
Robert