PIC 12F509 begins to heat at power up

[Pedro Pinto]

Hello

OR... new revision silicon is acting up (doubtful).

This is always my opinion. I will order a few Pic's
to test.
The inputs are not the problem i have wired for the
tests all inputs to vcc and the problem are the same.

Regards
Pedro

[Acetronics2]

Hi, Pedro

Could you post a piece of scheme ( just around the PIC - with reset circuitry ! )

Alain

PS: in your code, you should preset your outputs ( even inputs ) BEFORE the TRIS command ...

[ErnieM]

I went thru your code a bit to count I's and O's: looks like you have two outputs.

While you wait for your chips to arrive you may want to try this: (assuming you can ICSP this board) make up some test programs, either 4 programs to try each of the two output lines high and low, or use 1 input to step thru the combos.

That way you can see if a single output being hi or low is causing the current.

Acetronics' comment about presetting GPIO's before TRIS is well taken: GPIO is undefined after a reset and perhaps a momentary state collision is occasionally taking down the power supply and ending the program right there.

Post the schematic (as much as you will).

[Pedro Pinto]

Hello ErnieM

I not preset GPIO before TRIS, i make only a alias from the pins before TRISIO

Attached the schematic

Regards
Pedro

[Archangel]

I not preset GPIO before TRIS, i make only a alias from the pins before TRISIO
Pedro

Hi Pedro,
That was the point, that you should, so when TRIS makes the port an output it does so in a state chosen by YOU, not the devil.

[Pedro Pinto]

Hello Joe S.

English is not my natural language, sorry i not understand very well what
you mean in your answer. Is anything wrong in this code?

DEFINE OSCCAL_2K 1
'
sepic_ok var GPIO.3        
call_shutdown var GPIO.4
sepic_on_off var GPIO.5
pulsador var GPIO.2
am_on_off var GPIO.1
'sense var GPIO.0
'
TRISIO = %11001111
'
low sepic_on_off        
low call_shutdown       
'						
ciclo var word
conta var byte 
conta2 var byte
flag_pulsador var byte

Do you think that i must change it? if yes, what?

Thanks
Best regards
Pedro

[Archangel]

Hello Joe S.

English is not my natural language, sorry i not understand very well what
you mean in your answer. Is anything wrong in this code?
Pedro

Hi Pedro,
I have not time to check data sheets, it's WorkTime , but check what I did below, the comment in blue is because I have not checked the data sheet.

DEFINE OSCCAL_2K 1<font color=blue> 'is this correct? </font color>
'
sepic_ok var GPIO.3        
call_shutdown var GPIO.4
sepic_on_off var GPIO.5
pulsador var GPIO.2
am_on_off var GPIO.1
'sense var GPIO.0
'
GPIO = %00000000 '<font color=red>change to suit Your needs</font color>
TRISIO = %11001111
'
low sepic_on_off        
low call_shutdown       
'						
ciclo var word
conta var byte 
conta2 var byte
flag_pulsador var byte