Hey there. So I had to replace the fc on my explorer lr (goku F411 v2) and the dji osd is popping up, but not the betaflight OSD. I wired it the same way as last time (when it did work), then tried the other uart’s. Then I figured it doesn’t work anyway so I switched the TX and RX wires. No matter what I did, I still had video and dji OSD, but no betaflight OSD.
So my question is, how does the OSD show up in the goggles? Does the fc figure out information and send it to the goggles through the TX wire? What do the TX and RX wires do if I’m still getting video regardless of how I wire it?

Just curious.

The RX and TX wires between the FC and the DJI Air Unit / Caddx Vista are simply just used for an MSP data connection which provides the DJI FPV Goggles with the OSD data. It is then up to the goggles to render the data in the correct locations on the screen. You need to enable MSP in the Ports tab of Betaflight Configurator on the UART that the Air Unit / Vista is connected to and you need to have Custom OSD enabled in the goggles.

Make sure you connect TX from the Air Unit / Vista to RX on the FC, and RX from the Air Unit / Vista to TX on the FC.

So if I switch the wires (tx to tx and rx to rx), the I’ll still get video but it’s the osd information that wont be correct?
I understand the basics of setting up the configuration in betaflight with the way I wire the fc (like turning on soft serial or uart) and how tx goes to rx and vice verca.
I guess what I’m asking is is it possible I could have burnt something on the fc while soldering that would only affect the osd? Because it’s the program in the fc that produces the betaflight osd? And Flywoo confirmed the cli diff is correct.

Why did you have to replace the FC?

Does voltage show up in the DJI OSD? Does it switch out of low power disarm when you arm? If not, it's possible you fried one of the diodes on the Vista. Use a multimeter to see if either the TX or RX pad is shorted to ground. See here for more: https://intofpv.com/t-caddx-vista-bad?pi...#pid131777

Video comes from the camera to the Air Unit / Vista. It doesn't go via the FC on a DJI FPV system build. You can disconnect the RX and TX wires from the Air Unit / Vista and you will still get video.

If the MSP connection isn't working then you just won't get Betaflight OSD. You will still get a video signal.

Are you using a DJI Air Unit or a Caddx Vista?

Using caddx vista. I replaced it because I crashed and some wires were ripped out of the gps. And... when soldering new ones back on, something on the fc melted/popped off. I’m guessing a diode or something important because nothing worked after that.
So it sounds like it’s the MSP? I do get signal strength, but I don’t remember getting voltage.
Is that an issue with the fc then? I kind of understand the basics of a master slave protocol but not how it works with flight controllers.
Everything else is working with this one, just not the betaflight osd. So it’s not a huge deal, just trying to understand what’s happening.

The signal strength you are seeing is for the DJI system itself (DJI FPV Goggles to Caddx Vista, and DJI Controller to Caddx Vista). That information comes natively from the DJI system and not from the FC.

The Betaflight OSD not working means that you have likely fried one of more of the protection diodes on the serial data lines of the Vista as mentioned by V-22. All the details as to why that happens and how you can fix it are in another of my posts that V-22 also linked to, repeated below...

https://intofpv.com/t-caddx-vista-bad?pi...#pid131777

Nice. My vista is wired with the battery. When I started the hobby, I had a shop switch the camera with the caddx vista and that's how they set it up. I've been doing the same thing since. I definitely don't have the skill level to try and fix it so I'm glad that's the only thing that got fried and not the whole unit. Thank you for the info.

Lastly, I was wondering if this mateksys connector is wired correctly. Never noticed it before, but shouldn't the power out go the vista and power in from the battery? 


   
   

Is the Matek Voltage Regulator is for the Vista? Or is it for something else on the quad? The Vista can actually take LiPo voltage up to 6S do it doesn't need a voltage regulator but if you do connect it direct to LiPo voltage then it's important that you install a low ESR capacitor across the LiPo pigtail connections.

It's a bit difficult to see from the photos but for the Matek Voltage Regulator wiring, the LiPo voltage needs to be going into the 6-30V pad and then out of the 5V/9V pad to whichever peripheral it is intended to be powering (i.e. the Vista or something else).

Okay. So it is wrong. I’ll probably just take it out and just wire the vista to the board for power. Sucks that I wont have all the features of a betaflight osd. It’s got helpful information and looks really cool in the goggles.

Thanks again for the help.