The HeadPlay HDs are great goggles by themselves, but with a little work, you can turn them into an even more versatile “Fat Shark” DVR style goggle. The same is also true with the Quanum V2 Goggles. In both cases I wired them up so they could utilize a DVR and ability to do 1.3 GHz on a toggle switch. Here are all the juicy details on how I achieved this as well as troubleshooting I did with the Headplay HDs to clear up diagonal lines as well as a comparison of the HMDVR to the RMRC.
HeadPlay HD Goggle Mod
Here are the parts you need to make this happen:
DVR: HMDVR Mini DVR $25 (and ships fast)
Receiver: 1.3 GHz Fat Shark Dominator NexWaveRF Module $38
DIP Switch: For switching frequencies on the 1.3 module, here $5.65 for 10
Lipo tester/LED: For monitoring the voltage reading on the outside of the goggles, $5.18 here
Lipo Alarm: For setting a buzzer at 11.1 volt (or similar), like this Usmile 3 in 1 for $14.59
Toggle Switch: SPDT To toggle between 5.8/1.3 (power on / off ), here on Amazon $4.95 for 3
Misc: Servo wires and solder etc
5.5 MHz Ceramic Resonator Chip (for sound from 1.3 non-Fat Shark transmitters): On ebay for $5 (this turned out to be the wrong part, see below for the new part)
Headplay HD Mod
I felt a diagram was needed to understand how all of this would work out..
Here is a hand drawing diagram of the specific locations for everything, as contributed by “hobaoe” from the RCGroups.
Basically we utilize the fact that the goggles have two inputs AV1 and AV2. AV2 is important because it allows us to do video playback of the HM DVR by switching to AV2 and holding in the K3 button to go to playback mode. We pretty much just splice the two receivers together into the AV2 wiring (per the diagram).
First we just crack open the goggles by removing some screws and taking the top plate off, we can get at the Mainboard as below.
Under the mainboard reveals the stock 5.8 receiver (in this case I have the original HD goggles, so this is not the new raceband 40 channel one).
We trace the white plug on the 5.8 module back to the mainboard, this reveals where AV1 is located.
For the wiring on the 1.3 module this is what this ends up looking like. I had trouble initially on the DIP switches but eventually got the wiring straight.
Here is an exploded view of everything in progress. I used servo connectors for the ends of the video/audio leads coming from the mini DVR.. I used JST connectors for power and made sure to leave those exposed on the outside for ease of access if I need to swap things out later.
A closer few looks at the DIP switch wiring.
Here is the view once I had everything done and back together. Note, that cramming all the wires under the white “lid” was a bit difficult, so keep the wires as short as possible to prevent bunching.
Quanum V2 Mod
For the Quanum’s, I initially wanted the same exact setup, except at first I started off using the RMRC DVR. I also had to make a special audio jack on the outside for connecting a headphone or “speaker” on the outside. I also did not have another 5.8 Fat Shark laying around, but I did have my ImmersionRC UNO5800, so I went with that for the 5.8 side of things. Everything else down to the Toggle and Dip switches were the same basic principal.
Possible issues with picture quality with the Quanums + RMRC DVR
I was testing the Quanum Goggles and found that when I had the RMRC DVR connected, the picture quality was slightly less clear and less sharp, maybe even slightly dimmer. I later found out I had an issue with the DVR itself, so now I’m unsure if really was the result of having the DVR in play on the Quanums. I have ordered another Mini DVR and I’m going to connect it and see if the same situation occurs. Check back in the near future and I should have an update on this possible issue.
Getting sound on 1.3 NexWav (for either Goggles)
In order to get sound to work coming out of the 1.3 GHz NexWaveRF Receiver, we must use a 3 Pin Ceramic Filter Crystal Resonator L5.5M 5.5MHz in place of the existing one. This is to allow sound to flow from Non-Fat Shark transmitters to Fat Shark (NexWaveRF) receivers. If you already have a 1.3 Fat Shark transmitter then you dont need to worry about this. My first attempts at swapping out the 6.5 resonator failed, but only (I think) because the ebay vendor sent me the wrong type. Below is an image of the resonator I first tried changing. In the first image its the top one.
I ended up removing the outer wall so I could more easily get at the pins. I also applied the iron to the underside of the board (3 solder points), to loosen up the original resonator. As you can see the 6.0 labelled one from ebay that was supposed to be 5.5 is wrong and hence why I got static when testing audio. Basically if you are going to change the resonator, depending on which one you change, thats the wire/connection off the receiver you should use.. so change 6.0, use the 6.0 connection to the audio input on the goggles.
At this point I’ve found another vendor with the 5.5MHZ Resonator parts located here. Once they arrive i’ll test them.
Issues with Diagonal lines on the Headplay HDs and Clarity Comparison with RMRC DVR
I ran into an issue, particularly with the 1.3 ghz receiver, where I was getting strong diagonal line presence on the goggle display (Quanums dont seem to be that bad). I found that the culprit seems to be in wire arrangement, as I cracked it open and re-arranged and this seemed to fix things. I also swapped av1 and av2 to see if this helped. It may have been the combination of the two, but now the lines are barely visible in the main live view (now on Av2 not Av1). I initially got 1.3 cleared up and caused 5.8 to have more, but after opening and arranging wires differently, both are much better.
Now the real issue is that there are lines on the HMDVR. I’ve tried several tests to clear this up. I tried hooking up the Git2 to the HMDVR directly, since it was easier than trying to power the CCD camera, since the Git2 has its own battery. The results are in the video below. The image was free of lines. In that test I powered the HMDVR from the HeadPlay HD Goggles 5v output. I also wanted to compare clarity of the HMDVR vs RMRC and the RMRC is much sharper.
Here is the full video on the noise issue as well as the clarity comparison:
For a future test, I’ll likely power the HMDVR from another 5v source that isnt the goggles and see if the lines still persist. I’m guessing they will but we will see. In the end it might involve cracking open the goggles once more and adjusting wires and maybe putting copper shielding on them to eliminate all the noise completely.
Check back to the article soon, as I’ll be updating the resonator replacement progress as well as testing the mini-dvr with the headplays. There will be more videos up here soon too.