I know I must use some resistor, but which value? Should I use Ohm Law to calculate it?
Because Arduino can be powered with 3V or 5V, but my buzzer operates at maximum 2V, I am wrong? If I don't use a resistor to lower the current it will mostly burn...
Sorry for my ignorance, but I'm trying to learn while I make some samples/tutorials/projects I find around Internet.
The buzzer is 16 ohms.
Since it has a low resistance and it is a mechanical device (highly inductive), use an external power supply to power it.
There is a schematic in the data sheet you can follow.
Well I got:-
1.5V @ 16R gives a current of 9.3mA for normal operation.
Then you drive it at 5V and want 9.3mA through it so the total resistance is 53.7R but the sounder is already 16R so subtract that to give 37.7R.
Now that is not taking into account the Vsat of the transistor but that would only lower the required resistance, so I would stick with 37R.