Hi. I am currently building an FPV system in my RC car. This is the scheme I created for this:



This is the cable I made to get 16.8V from the original two 2S batteries attached to ESC:




Everything looks ok and I'm getting the correct voltage (I don't have DJI AU or FC yet) but on the side of the ESC there is an 8pin port for connecting LED lights, where also the voltage is 16.8V and using this connector would save a lot of cables and be more clean.






Is it possible to power the DJI AU + FC (F4/F7) and GPS from this port?
The flight controller is only for OSD and AU power. 

How much amperage does the AU + FC need? Will it be more than the original lights plugged into this port? Can it be measured somehow? 
If I connect the 5V BEC to the 16.8V pins, then connect the phone via USB with an application that measures the charging power, will I get specific results? 


This is what it looks like so far: 









Thanks for the suggestions.

There are FC that can be powered directly from LiPo and they will have all the BEC needed to power everything your wanting.
There’s several ways to get your FPV system working and your method could but without knowing what is coming out of that pin you may risk an air unit.
If your going to a FC, use its BEC to power up the devices.It will have designated pads specifically for powering the air unit,gps,etc.... The right FC will also have an OSD you can adjust screen in betaflight.
By picking the right FC it’ll have several BEC built in with correct voltage and amp needs and the FC will get its power directly from LiPo not the pin in ESC.

I can't find any specs for the accessory port on the side of the Traxxas VXL-6s ESC module but the DJI Air Unit can draw 0.5-0.6A of current, so as long as the internal BECs in the VXL-6s that power the pins on that accessory port can supply that amount of current required for the Air Unit, plus any additional current required for the other accessories you intend to connect to it then you should be fine using that accessory port as a power source for the Air Unit.

I just read something on the Traxxas web page for the LED kit (HERE) which states that the output from that accessory socket on the VXL-6s ESC is raw battery voltage and not voltage that is regulated via a BEC. In which case you need to be aware of a couple of things:-

1. If you use a 6S battery on your RC Car the voltage from that accessory port will also be 6S voltage which the Air Unit can't handle, so be careful of that because anything higher than 4S voltage will fry the Air Unit.
   
   
2. When using raw unregulated battery voltage it is highly advisable to install a 1000uF 35V low ESC capacitor across the +ve and -ve connections of the power rail to the Air Unit. This will help to mitigate any electrical noise and limit voltage spikes which can potentially damage the Air Unit.
   

Otherwise just do what Rob suggested and buy a flight controller that is specifically designed to have an Air Unit connected to it and which has a dedicated onboard 8-10V voltage regulator and a socket for the Air Unit connection wiring harness to plug directly into.

Thanks for the answers, so I will try to find a 6S powered FC with AU port/pads and I will measure the voltage at the connection point before adding the AU to make sure it is correct.
I'll let you know in a month when I have all the parts.
For now, I am waiting for the DJI move with the new AUv2.

(07-Apr-2021, 05:58 PM)AndyZ Wrote: For now, I am waiting for the DJI move with the new AUv2.

There is no Air Unit V2. DJI are just giving Caddx a license to continue manufacturing what DJI no longer have any interest in manufacturing themselves. We don't know yet if Caddx will only manufacture the Vista or if they will also manufacture the Air Unit as well. We're not even sure if Caddx will manufacture the 1080p DJI cameras or if the only cameras going forward are going to be the 720p Caddx Nebula range.

If you can find a vendor who still has Air Units in stock then I would probably advise that you buy one before they all disappear.

Here’s a diagram  of one FC that will work.There’s several available.
 
One advantage of a FC is using Betaflight to setup OSD and GPS.
  

Here’s a link to diagram.
Looks like my picture didn’t work.
https://cdn11.bigcommerce.com/s-wrwm6/pr...ctions.jpg

I just noticed that the availability of the Ait Unit is destroying my entire project. Analog and Sharbyte are a bit weak and I am thinking about OpenHD now.
It's interesting to build, but I'm afraid ground-level coverage may be poor. And a ground station is required. I don't know what to do. It's a bit weak that in 2021 there is no decent HD link.

New stock of the Air Units (V1) may be coming if Caddx have been given a license to manufacture those as well as the Vista's, but we just don't know yet, and we don't know if they will be to the same quality as the original DJI manufactured Air Units. DJI are keeping everyone in the dark as per usual with no communication or transparency whatsoever about what is happening, so all we can do is sit back and wait to see what happens.

(08-Apr-2021, 06:00 PM)AndyZ Wrote: I just noticed that the availability of the Ait Unit is destroying my entire project. Analog and Sharbyte are a bit weak and I am thinking about OpenHD now.

There is enough room/space on your ground vehicle for OpenHD hardware and being opensource you can get your own hardware. The OpenHD system does have a higher latency which is something to keep in mind.

FPV flyers require compact size, light weight and lower latency which is why OpenHD has not been very popular amongst us.

If you are looking for an air unit heli direct has some in stock.

At the moment I will stop for a few months on the analog. I ordered a receiver with a video transmitter for € 50, and I have the camera from an old drone

Cool. What kind of range are you getting?

(20-Apr-2021, 11:03 PM)kafie1980 Wrote: Cool. What kind of range are you getting?

About 200 meters / 650 feet. Because stock traxxas TQi radio was losing connection.
Video link: €20 TS832 600mw ttransmitter + €30 FPV OTG android reciever with two antennas.