druck wrote:

> On 13/06/2018 14:16, R.Wieser wrote:
>>> measuring between a GIPO & 5v reads
>>> 0v, so they are both the same voltage.
>
> No!

Correct.

>> And as the OP (correctly) stated, they are (thus) both at 5v.
>
> No!

Correct

>> And if his measurement is correct (and it is), and he reads 0v
>> difference, than, as Mark has got the same result on his voltage meter,
>> his leads should logically be at 5v too (even though they are not
>> touching anything but air).
>
> No!

Correct

> If you measure between 2 pins and get 0V it /could/ mean they are at the
> same potential, or it could mean there is *NO* connection between them.
> That's why you always measure from the common ground to the pin.
>
> Ground to 5V should give 5V
> Ground to GPIO set high should give 3.3V

Almost there...

> 5V to GPIO should give 0V because they aren't connected.

but not quite.

--- SoupGate-Win32 v1.05