The HiFiBerry power controller is based on the ATMEga808 with the following external components connected:
| Component | Pin ATMega | direction |
|---|---|---|
| power switch | PA0 | output |
| LED blue | PD1 | output |
| LED green | PD2 | output |
| LED red | PD3 | output |
| rotary encoder A | PC0 | input |
| rotary encoder B | PC1 | input |
| rotary encoder button | PC2 | input |
| Pi RS232 RX | PF0 | output |
| Pi RS232 TX | PF1 | input |
| Pi I2C SDA | PA2 | input/output |
| Pi I2C SCL | PA4 | input |