LCD with I2C not displaying characters

Darkboss99:
I am using hd44780 for testing and it works...

Well I compiled hello world and everything and it worked

but now I came back and wired it again (properly) and it just shows the white boxes

You say it is working and then that it isn't.
I don't understand.

Wired it again?? What does that mean? and why? if everything was working why re-wire it?
"the white boxes"... it very much matters if the boxes are on all lines of the LCD or just some of them.

  • Did you update the library to the latest version (currently 0.9.3) ?
  • Is I2CexpDiag working? (all tests pass and you see the expected output on the LCD)

--- bill