Diversity for Fat Shark Attitude V2 FPV Goggles

I fly micros mostly and also a 180 quad with a 25mW “legal” raceband transmitter and was looking to get better video.  All the cool kids use diversity on their fancy Dominators but there’s no real option my Attitudes.    While there are now many different diversity options from the older 2 board ones to the LaForge style OLED ones they all involve some serious mods to the electronics and cutting on the case.  I was hesitant to do this radical and irreversible change.  Until now.

WIth the diversity module (also previous DVR mod)

I decided to get the Realacc RX5808 Pro Open Source 5.8G 48CH Integrated Diversity Receiver w/ OLED for Fatshark Dominator Goggles  from Banggood.

I chose this one mostly for price but also I had read this open source one would work with Attitudes.    I suspect any of them would work as the Rx modules have a common pinout but I didn’t investigate too much on the details.  For such a major mod I really just jumped into it.

The Fatsharks open up by taking off the strap, eyecups, and then with 2 screws.  The main board with the Rx module soldered on is attached with connectors and slides out easily.  In this photo there are the additional wires from the DVR mod that I did a few months ago.  They are soldered on but a connector on the DVR so it pops out easily with the main board.

Cracked open showing the bottom of the main board

Next up was desoldering the Rx module which was a challenge.  The metal tabs from the rf shield are soldered to the main board as are about 10  .1″ pins header.  I used the trick I saw on another article to heat the pins up (you can hear them “squeak” when they are loose in their hole) and only then grab with needle nose and pull out quickly.  You don’t want to grab it until it is hot enough or the pliers will take the heat from the pin.  This worked very well but Ground pin was still difficult.  I suspect they have a thick ground plane with no thermal isolation sinking the heat away.

For the metal tabs I ended up pulling up the PCB traces.  Normally this is bad but in this case it doesn’t matter as the new module doesn’t have similar tabs to attach.

FIrst test showing spectrum display

Once the pins are out I used a sucker and solder braid to clean up the holes and the new module dropped right in.  Quick solder and time for a test!  I only used one antenna but success!  I need to learn how to use it better but it works.

Next up was cutting the case so it could fit.  I used a sharpie to estimate where to cut and then used a band saw and dremel to quickly cut open the opening in both halves.  The cutting seemed to melt the plastic more than cutting it but it did work to cut off the piece and the melted edge was easy to clean up with diagonal wire cutters.  I had a slight mis-alignment on one edge but not really noticeable.

All done

The final minor derp is getting the two red wires on the DVR reversed (red is positive power, red is also video in — wtf?).  It was easier to swap the wires on the connector than to open it up and resolder the wires.  Now the DVR is working too.

So how does it work?  Awesome!  I tried a few tests with the tiny whoop around the house and it worked great.  I could see the diversity change antennas in some local tests moving the goggles around.    Outside I was able to fly to my previous limits with no problem at all.  The only breakup at all was right overhead presumably the omni pattern is not good in the middle of the donut and the patch pattern was orthogonal.

All in all the mod took about 2 hours from set up to clean up.  For less than $50 including the high gain patch antenna this was a very effective upgrade to make flying more fun and put off what would be an expensive upgrade for better goggles.  I also purchased an additional high capacity battery because I assume this draws more power with 2 Rx modules, additional CPU, and the OLED display and also I am still running the original 800mAh battery from almost 3 years ago now and good to have a spare.


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