If your board has no printed labels, check out its pinout diagram documentation (found on the board's Arduino Store page). PWM pins in the diagram have the same tilde sign in front of the pin numbers.

and you can check out the full hardware requirements for all Arduino boards on the Wire Library Reference page. This gives you access to the Wire library, and you're now able to use all the commands.

You can find numerous ideas, tips and tricks everywhere in internet. Next is the complete schematic diagram of a little Arduino board for your everyday projects. Use the Atmega328P chip, with Arduino ...