basic input problem

Started by ricinecwh August 7, 2006
I am a basic beginner
I have a small problem and hope that it would not be too disturbed.

When I put the varied voltage into any ADC pin,
i dont know why the other ADC pin are also affected.

For example
When Pin16 is change from 3V to 5V,
Pin 13 will be affected and changed from 3Vto 5V also.

Is my basic chip have some problem?
or it is normal?
It is normal for non-connected pins to "Float" and even return the
value present on adjacent i/o pins. Now if both pins are connected
to different analog inputs and this is happening you may have a
problem.
Chris

----- Original Message -----
From: "ricinecwh"
To:
Sent: Monday, August 07, 2006 3:08 AM
Subject: [BasicX] basic input problem
>I am a basic beginner
> I have a small problem and hope that it would not be too disturbed.
>
> When I put the varied voltage into any ADC pin,
> i dont know why the other ADC pin are also affected.
>
> For example
> When Pin16 is change from 3V to 5V,
> Pin 13 will be affected and changed from 3Vto 5V also.
>
> Is my basic chip have some problem?
> or it is normal?
I have putted 9V into the ADC i/o pins ,
Will it break the pins?

--- In b..., "Chris" wrote:
>
> It is normal for non-connected pins to "Float" and even return the
> value present on adjacent i/o pins. Now if both pins are connected
> to different analog inputs and this is happening you may have a
> problem.
> Chris
> ----- Original Message -----
> From: "ricinecwh"
> To:
> Sent: Monday, August 07, 2006 3:08 AM
> Subject: [BasicX] basic input problem
> >I am a basic beginner
> > I have a small problem and hope that it would not be too
disturbed.
> >
> > When I put the varied voltage into any ADC pin,
> > i dont know why the other ADC pin are also affected.
> >
> > For example
> > When Pin16 is change from 3V to 5V,
> > Pin 13 will be affected and changed from 3Vto 5V also.
> >
> > Is my basic chip have some problem?
> > or it is normal?
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> I [] put 9V into the ADC I/O pins...

If you mean that you directly connected +9v from a stiff source like a
battery, yes, there is a good chance you damaged the processor.

It is current, though, that would do the damage. If the source
current is less than 40mA, according to the Atmel documentation, a pin
can survive.
Tom