ok, i will try with oscillator configured in HS

yes, the capacitors are 22 pF, (sorry) and the reset line is configured
for digital input (_MCLRE_OFF), when work ok, it read a little keyboard

thanks

RVP


Peter van Hoof wrote:

>You have selected the XT oscillator, 4 MHz is in the range where a HS
>setting with it's higher gain might be needed for some crystals needing
>a higher drive level. See what results you get with this.
>
>Peter van Hoof
>
>--- r-vallad@unete.cl wrote:
>
>>Hi all,
>>
>>i have an extraneous behiavor of a 16f48a, the same circuit, with the
>>same
>>program, sometimes start about 5 minutes after power on, sometimes
>>don't
>>start at all and another times it works fine. still is in protoboard,
>>but
>>it's a simple circuit.
>>
>>in software, i have this configuration (BoostC)
>>
>>#pragma DATA _CONFIG, _BOREN_OFF & _CP_OFF & _DATA_CP_OFF & _WDT_OFF
>>&
>>_LVP_OFF & _MCLRE_OFF & _XT_OSC & _PWRTE_ON
>>
>>the circuis has a external 4MHz xtal oscillator, coupled with a pair
>>of
>>22nF condenser to ground. all of this is near the pic, the pic itself
>>is
>>decoupled with a 0.01uF and the only other component in the
>>protoboard is
>>a 16x2 display.
>>about 50cm apart, is the "1st floor" of the circuit, a 3-8 decoder,
>>6-not
>>gate and a uln2003 (i think) driving 6 relays, transformer, lm7805,
>>electrolytic & decoupling condenser, etc, the power supply.
>>
>>- the power on can be done at the transformer o "switching on" only
>>the
>>protoboard (pic + display). same result
>>- there is nothing connected to the relay, the relays don't turn on
>>(or
>>almost don't click) on power on
>>- when the pic start, it switch on / off several times the relays, it
>>works fine
>>- i don't have a datasheet of the xtal, it's 4MHz generic.
>>
>>anyone have some idea of what happen?
>>
>>thanks.
>>
>>RVP
>>
>>
>>
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>


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