I have a RPi 4 Model B 8 GB working as a companion computer for a Pixhawk 5x. I managed to establish the Ethernet Port between them.
But now I don’t know what would be the best solution to power the RPi. Should I do this trough the Power Distribution Board or through the Flight Controller itself?
My batteries are 5000 mAh 4S. My drone kit is the X500 V2.
It’s better if you do it through the Power Distribution Board since the Flight Controller power is limited by the current it can provide.
If you don’t want to modify your Power Distribution Board, you can always power your companion computer with an extra battery and a voltage regulator. These are probably small and light enough that it won’t matter in your design.
First guess or measure RPi 4 current consumption, which may be several amperes. It may be too much for the 5V regulator inside the PDB, but a visual inspection and a test should help.
You can solder an additional JST connector at the PDB battery pins, and there attach a regulator (4S to 5V) with enough current capability. At its output a DIY USB-C cable (two wires).
But may be you have an ESC whose 5V BEC (if existing) is not used, and should have around 3A capability. So route its signal input to the FC, and its 5V wire and GND to a DIY USB-C cable.
try matek sys pdb board, it has one can handle up to 12s, and it comes with 5v/5a, and 12v/4a bec, the quality is good, if don’t want from PDB, can buy a UBEC directly drop the voltage from battery.
Thank you guys, I’ve ordered a Pololu power supply to drop the voltage from battery and I will connect it between the PDB and the Raspberry Pi.