Vcc-----+--
        ! 
        ! 
        /
        
        / Pullup
        
        ! 
Port <--+
Pin     !   
        ! 
        !   +----
        !   !
        !   (
  Relay    ( Relay
Contact    ( Coil
        !   (
        !   !
        !   +----
        ! 
        ! 
Gnd-----+---