ATmega328PB supports four additional GPIOs on PORTE [3:0].
The GPIO pins PE2 and PE3 are assigned to Pin19 and Pin22. PE2 and PE3 are multiplexed with ADC6 and ADC7.
Pin3 (GND) and Pin6 (VCC) are replaced by PE0 and PE1 respectively. PE0 is multiplexed with ACO.
| 32-pin TQFP/MLF package | ATmega328 variants | ATmega328PB |
|---|---|---|
| Pin 3 | GND | PE0/ACO |
| Pin 6 | VCC | PE1 |
| Pin 19 | ADC6 | ADC6/PE2 |
| Pin 22 | ADC7 | ADC7/PE3 |