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Set port1 pins as 0 or 1

radhakrishnan murugesan over 13 years ago

Dear all,
i am using P89V51RD2 (philips) 8051 micro-controller. i am doing some samples with NSK developemnt kit. In this i want to set the Port1 pint 0 to 7 as high/low continiously. I tried this by using the following lines,

P1 = 0x00 ;
delay(10000) ;
P1 = 0xFF ;

but still i am always getting around 5V on these pins. i searched lot of forums, but in that also they mentioned like this only. Kindly give your suggessions.......

Thanks and Regards
Radhakrishnan M

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0 erik malund over 13 years ago in reply to radhakrishnan murugesan

Suppose if i initialize the [port pin] value with 0 then whenever i connect some input in this port [pin] then i will show either off or intermediate state
????

if you connect an input to a port pin that is set to 0, you will, of course, see a 'low' at that input.

Erik
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0 erik malund over 13 years ago in reply to radhakrishnan murugesan

Suppose if i initialize the [port pin] value with 0 then whenever i connect some input in this port [pin] then i will show either off or intermediate state
????

if you connect an input to a port pin that is set to 0, you will, of course, see a 'low' at that input.

Erik
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0 ImPer Westermark over 13 years ago in reply to erik malund

You might also see smoke, since the processor pin will try to short whatever is connected to ground.
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