ATmega168 PD3 PD4 GND VCC GND VCC PB6 PB7 PD5 PD6 PD7 PB0 PB1 PB2 PB3 PB4 PD2 PD1 PD0 PC6 PC5 PC4 PC3 PC2 PC1 PC0 ADC7 GND AREF ADC6 AVCC PB5