PWM pins work the same way across all Arduino boards, so you don't need to go out of your way to buy a Mega if you already have a board supporting PWM. On the Uno, Nano, and Mini, the PWM pins are ...

Note: Some pins are not connected on a standard Arduino Uno R3 but still listed so you can use them if you had a custom board. It might also be possible that your ISP header of the 16u2 is flipped 180 ...

You also need to solder the additional 4 pin header to access all 7 PB i/o pins. D7 has PWM! (other not connected pins with a timer as well). The 16u2 pinout is the same for Arduino Uno/Mega. Keep in ...