반응형 ATmega16U21 ATmega8U2/ATmega16U2/ATmega32U2 UGND and GND The UGND and GND pin of ATmega is not connected internally. Thus, you have to connect the pins externally. If you don't connect UGND and GND and plug USB connector, the ATmega chip and USB port can have a serious damage. Be cautious ! 2016. 9. 28. 이전 1 다음 반응형