Raspberry Pi 4 Model B (4GB) Wiring Guide/Advice

Hi all, have been following OpenHD for a while now and had to sign up as I received some equipment to get involved!

First of all, thank you to those who have posted so many helpful things for us newcomers. Many things I’ve been able to read and learn before even plugging anything in.

I ordered the following:

  • 2x Raspberry Pi 4 Model B
  • 2x 32GB Sandisk Extreme Micro SD Cards
  • 3x ASUS USB-AC56
  • 1x Raspberry Pi Camera V2.1 plus 300mm cable
  • Misc cables (Micro HDMI to HDMI, USB C for power, etc)

I couldn’t help myself and had to test it out as soon as I could. I downloaded the software image and flashed the two cards, plugged a USB-AC56 into each Pi, plugged the camera into one and the other into the TV and had an image. Too easy, honestly took longer to open all the packaging than it did to initially test everything.

Next day I thought about hooking up the second USB-AC56 to the ground end, and it worked, for all of three seconds of image before the screen went black. I believe this is either due to power limitations of the Pi USB ports or the USB hub I’m using is just rubbish (probably the second option, as this later worked fine with both USB-AC56s connected to the ground Pi via the supplied ASUS desk-mounts/USB-extensions).

Moving forward, away from the dinner-table-setup I need to build-up the air and ground ends. This means soldering, removing failure points (USB connectors, etc). I have a supply of Castle Creation 5v 10A BECs that I plan to use on both ends.

So, now I have a couple of questions regarding the wiring and connections. I have seen people soldering to previous Pi versions, but has anyone hooked up a 5v supply to the Pi4B to supply power to the Pi itself and obviously to provide a heftier supply to the USB ports… I’m needing to know what to solder to where. Does anyone have any images/documentation about this process?

I would assume I’d split the 5v from the BEC, one side going to the GPIO pins to power the Pi and the other set directly to the USB-AC56(s), and then connecting just the D+/D- from the USB-AC56 to the Pi (can the D+/D- of two wifi cards go to the same D+/D- pads on the Pi?).

On the air end I’d like to have everything soldered, but the ground end I think I might get away with USB plugs (secured with hot glue). Should I then pull apart my USB hub and supply 5v directly there?

Any feedback on this most welcome. Am also happy to document the builds as this would also likely answer questions from people using Pi4B(s) in future.

Cheers everyone, my project is ongoing and is already attracting attention from my employers (we manufacture autonomous fixed wing aircraft, full stack, designed our own hardware, software and aircraft!) looking forward to becoming a more active member here!