Jumper settings:
An external power supply can be used to power digital inputs using a correct configuration of jumpers JP2 - JP5. Using an external power supply also includes galvanic isolation of digital inputs. The Unipi 1.1 must be unplugged from power during jumper configuration. After finishing the adjustments and connecting the external power source's negative pole (see below), you can plug back the board's power.

This picture shows the default jumper settings. Digital inputs are connected to the internal 12 V⎓ power supply. The P02 terminal now provides 12 V⎓ voltage.

The JP2 jumper is moved away from the Raspberry Pi with digital inputs still connected to the 12 V⎓ internal power supply. The P02 terminal now acts as GND for the entire board:

Jumpers JP2 and JP3 are moved, digital inputs I01 and I02 are ready for connection of an external power supply. Terminals I03 to I14 are connected to the internal 12 V⎓ power supply. The P02 terminal can be now used to connect the external power supply's negative pole for inputs I01 and I02:

Jumpers JP2, JP3 and JP4 are moved, digital inputs I01 to I04 are ready for connection of an external power source. Terminals I05 to I14 are connected to the internal 12 V⎓ power supply. The P02 terminal serves for connection of the external power supply's negative pole for I01 and I02. The I01 terminal can be now used to connect the negative pole of an external power supply for I03 and I04. Terminals P01 and P02 and their corresponding inputs are mutually isolated:

Jumpers JP2, JP3, JP4 and JP5 are moved, all digital terminals are ready for connection of an external power supply. The P02 terminal serves for connection of the external power supply's negative pole for I01 and I02. The P01 terminal now serves for connecting the external power supply's negative pole for outputs I03 to I14. Terminals P01 and P02 and their corresponding inputs are mutually isolated: