Or a suitable diode can be placed in series between pin D10 and where the 4.7k resistor attaches to the line to the transistor base. If the diode's orientation is correct, it will prevent short circuit of pin D10, when it is set to OUTPUT and HIGH. In this case however, you will only be able to turn the backlight ON with pin D10 in INPUT mode, backlight OFF with pinD10 in OUTPUT mode (either HIGH or LOW). You will have no intensity control.Refer to the following corrected schematic - note that the free end of the diode should have been labeled as connected to Arduino pin D10, rather than labeled with a cryptic BT.
EDIT: ok now i know that there is a version before v1.0, and since mine does not have printed 1.0, I am in doubt....
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