As far as I know, none of the Pi's pins are 5 volt tolerant, it is only when configured and used with the i2c bus that they are tolerant.
If these same pins were reconfigured to general purpose use, they would not be 5 volt tolerant.
I think that the issue is the way that the i2c bus operates and how it is pulled up/down.
anita2RIn reply to Re^4: i2c lcd Custom Characters
by anita2R
in thread i2c lcd Custom Characters
by anita2R
| For: | Use: | ||
| & | & | ||
| < | < | ||
| > | > | ||
| [ | [ | ||
| ] | ] |