16F628A and RA5 (MCLR pin)

[Jerson]

RA5 (MCLR) cannot be used as an output. You may only use it as MCLR or input.

Jerson

[peu]

Ok, so if I swap one of the segments with one of the switchs it should work? say for example ra7 swapped for ra5 and set trisa as:

trisa=%00100000

Do I need to change something else?


Thanks

[mister_e]

you're right! nothing else to change

[peu]

I just tried the attached circuit with this code:

@ DEVICE pic16F628a, INTRC_OSC_NOCLKOUT
@ DEVICE pic16F628a, WDT_ON
@ DEVICE pic16F628a, PWRT_ON
@ DEVICE pic16F628A, MCLR_OFF
@ DEVICE pic16F628a, BOD_Off '(off si es muy baja la alimentacion)
@ DEVICE pic16F628a, LVP_OFF
@ DEVICE pic16F628a, CPD_Off
@ DEVICE pic16F628a, PROTECT_Off


trisb =%00000000
trisa =%00100000
cmcon =%00000111 'Comparators Off

porta=0
portb=0
loop:
if porta.5=1 then
porta.4=1
porta.3=0
else
porta.3=1
porta.4=0

endif
goto loop

and it only lits the led on ra3

Any idea? Maybe its a simulator issue (proteus vsm)

Thanks

[mister_e]

PORTA.4 is an open drain type. so you can't really drive it like that... you can drive it low but not high... well not directly.

BTW you really need to a resistor in serie with your LEDs to limit the current.

[peu]

Thanks Steve, I changed common cathode for common anode display and now it works as expected!!