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Starting with HDZero

 ·   ·  ☕ 5 min read

Like most people who have been in the hobby for a while, I started with analog VTX’s for FPV. But, after having a taste of what digital FPV was like after the chance to try a flying buddies DJI Mavic 2 with the DJI goggles, I kept an my eye on the digital FPV space, waiting for an alternative to DJI to enter the market. Now, don’t get me wrong, this is not because there was anything wrong with the quality of the DJI gear or VTX link - there is absolutely nothing wrong with that. I simply do not what to be locked into the DJI ecosystem since they have to treat their customers as idiots in order to comply with certain, in my opinion, oppressive consumer restrictions. Plus, you have to use the DJI goggles - there is no standalone VRX option.

So, I was very interested when I heard rumors that Fatshark were working on a digital system, which then turned out in reality to be the CaddxFPV Walksnail Avatar system. However, that has it’s own pros and cons, which I’ll get into another time. I then found out about HDZero, which could be used with existing analog goggles via a standalone receiver, or the dedicated goggles which were being made for the system. Which would run open source software for the most part (with some unavoidable binary blobs for some of the video processing and handling) and would also have some integrations with ExpressLRS. And even better, it would have an expansion bay allowing using of basically any analog goggle on the market - something which was previously said to be impossible for a digital goggle system. So naturally I was sold at the point, and joined the HDZero Goggles pre-order queue when they offered a discount.

It seems like I joined at a good time - as I eventually received what was referred to as the “batch2” goggles, due to some changes to the design due to the semiconductor parts shortages of recent times. I also managed to avoid the optics issues that some batch2 owners faced, as mine were held back after they were identified in units that had already been shipped. Now, it wasn’t (and still isn’t) all chocolates and roses… I also wanted to uses these goggles for analog, as I have some smaller quads that will probably never see HDZero, and also until I transition other quads over, I want to continue using analog VTXs. Unfortunately, it seems one of the other changes in batch2 created some issues with analog reception, which can only be fixed in the closed-source portion of the goggles hardware. Thankfully, however, by the time I received my goggles, there was already beta firmware available, which fixes a lot of the issues already. Plus, I had gotten the TBS Fusion analog module to go with these goggles, which seemed to have less problems than some other modules. However, more work is still needed, but the HDZero team are clearly committed to ensuring these goggles are the best they can be for both analog and digital FPV.

Since I ordered the Freestyle bundle, I also got the Freestyle VTX, and later ordered a Whoop Lite VTX to go in a TinyTrainer V2 (as a complement to the analog one I already fly). Once I knew the goggles were on their way, I then had to consider what frame it was going to go in. What better frame than one that Chris Rosser had designed… the AOS 5, since I predominately fly 5" quads. It was perfectly suited for the HDZero Freestyle , as it supported three sizes of mounting points (20/25/30mm), and the Freestyle VTX needs the 30mm spacing mount points because it’s a big boy. The build went together well, with a SpeedyBee F405 FC/ESC combo and Radiomaster RP1 to round out the electronics, and I have now flown that quad for several flights at my clubs local field. Preliminary range tests indicate that 25mw is fine for the main area I fly in, but I’ll most likely fly at 200mw as that will easily fly the full length of the field without any signal strength issues (and since this is the Freestyle VTX, that isn’t near it’s maximum power). I was blown away with the with the difference in the picture - things were just so much clearer and sharp than they were with analog, and how flyable the system was when the signal was getting marginal. It has been quite enjoyable being actually able to just pull up the source code for the main goggles firmware when trying to figure out why certain things work or don’t work, and to see the fixes and new features being added regularly to the code, as well as considering wether to make changes to the code for my own needs, or as a pull request contribution.

So, as things stand right now, the HDZero Goggles have a lot of potential. The HDZero digital system itself is already reasonably well established, and a lot of racers seem to love it due to the low and consistent latency of the link, while having better video quality than analog. Plus, it is still continuing to develop, as indicated by a firmare update taht came out just before I received the goggles to added a new 1080p30 mode to the system generally. Once the analog kinks are ironed out, I think the goggles will clearly be the best in class for analog and digital, whether that be HDZero, Walksnail, or whatever comes next. I found the open source nature of the software appealing, as just like with EdgeTX, ExpressLRS or any other OSS project, if it doesn’t do what you want, you can change it yourself, or get someone to do it for you.

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