The Raspberry Pi GPIO connector has both the 3.3V and 5V rail available, so to have a more compact system, embedding the RPOf on the "shield" connected to the Raspberry Pi, can helps to reduce the space and number of boards.
The RPOf circuit and basics is the same but there are some modifications.
- The GPIO 5V is connected to the main 5V entry, but there is NO protection since the polyfuse on the main input is after the micro USB port.
An external polyfuse is required.
- An extra capacitor should be added to stabilize the power