USB Pi Pilot
This small project lets me manage the power supply of a Raspberry Pi used as a Kodi media player, following the power state of a television.
Most TV sets cut the power of their USB ports when they go into standby. A current Raspberry Pi cannot be powered directly from a TV USB port, because the maximum power delivered is insufficient: it requires a dedicated USB Type-C power supply. This circuit simply uses a relay to switch the Raspberry Pi power supply according to the TV state.
The 5 V from the TV USB port does not power the Raspberry Pi: it only energizes the relay coil. It is the relay that lets the dedicated power supply through to the Pi, or not.
The design files and the deliverables are available on the project GitHub page.
PCB
The PCB was made with KiCAD.
Bare PCB
PCB with the components soldered
As can be seen, for the connection of the Raspberry Pi and of its power adapter I chose to use solderable USB-C breakout boards.
The case presented below was designed accordingly.
Case
A case that can be 3D printed was designed with FreeCAD.
3D-printed case parts
Complete assembly