12C671 - GP3 problem

[Acetronics2]

Hi, Finance

could we see your config and declare stubb ???

better, whole PBP program if possible ?

Many, many reasons possible .... and crystal ball saturated.

Alain

[financecatalyst]

DEFINE NO_CLRWDT
DEFINE OSC 4
Define OSCCAL_1K 1
@ __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_ALL
'// For PIC12C671
include "modedefs.bas"

'// Define variables
ToTx VAR GPIO.0
PAUSE 30
'// OSCCAL=0
TRISIO = %111110
OPTION_REG = %10000000
ToTx = 0
INTCON=0
ADCON0.0=0
ADCON1=7

send:
if gpio.1=0 then
serout ToTx,N2400,["G0"]
Low ToTx
pause 10
endif

if gpio.2=0 then
serout ToTx,N2400,["G1"]
Low ToTx
pause 10
endif

if gpio.3=0 then
serout ToTx,N2400,["G3"]
Low ToTx
pause 10
endif

if gpio.4=0 then
serout ToTx,N2400,["G5"]
Low ToTx
pause 10
endif

goto send
end

[Acetronics2]

re,

1) did you try a simple pin test ??? just to verify pin is still alive ???

2) did you verify your 10k is Ok ??? ( logic 1 on pin when nothing done )

Also, Did you try enabling the CLR Watchdog ??? ...

Do all '671 react like this ???

Alain

[financecatalyst]

Hi, for some reason when I check the voltage on all pins, every pin except GP3 has 5V, whereas I don't know why GP3 is showing only 0.5V. They all are held high (5V) with 10K.

I also tried with 1K then 470Ohm, but voltage on GP3 is not going above 0.8V after that. Also just want to add that, my circuit is in such a way that it only gets power when a button is pressed. Buttons bring in the -Ve supply to the system from a 12V battery, also the -Ve goes to the 7805 so PIC gets its 5V as well.

[Acetronics2]

Hi, for some reason when I check the voltage on all pins, every pin except GP3 has 5V, whereas I don't know why GP3 is showing only 0.5V. They all are held high (5V) with 10K.

.

That looks much like a fried pin ... as it is an " input only " pin ...
You have to take care of these pins ... cause there's no clamping diode to VDD : must be treated as a full CMOS input with antistatic discharges handling precautions.

Alain

[financecatalyst]

Hi, I now got a chance to come back to this problem of my pic. Apologies for the delay in updating you.
OK, I have programmed another 12C671 taking care of static discharges. Now the voltage part on GP3 is working fine. It is pulled high at 5V. But making it low does not initiate the required serout signal.
Is there something I am missing in the code to make proper use of GP3 as an input?
Thanks

[financecatalyst]

Anyone there?
Please help