Production Update and Topside Design Improvements (Trident Kickstarter Update #21)

Original post : May 18, 2017

Hello everyone!

First off, we’re still on track with regards to the schedule we laid out in our last update.

As we enter the second half of May, many parts of the production ramp-up process will be happening rapidly, so we’ll try our best to keep you up to speed. In this relatively short update, I’d like to focus on the development of our WiFi Topside Module. As we described several updates ago, this is a part we’ve put a lot of energy into designing right. Making a box with a WiFi radio inside may seem simple, but creating a system with the versatility to handle a wide variety of conditions has required careful planning and execution. The design process for this subsystem has been a long and winding road, but we’re very proud of where we’ve arrived.

Thermal dissipation has been one of the key challenges we've faced in designing the WiFi Topside Module. The electronics onboard the Topside consume nearly five watts, which in such a small package creates quite a bit of concentrated heat that can easily exceed the limitations of some of the onboard chips. After observing troublesome temperature values on some of our initial prototypes, we decided to do more in-depth thermal analysis and realized that we’d need to significantly increase the enclosure’s external surface area to keep the system cool in warm conditions. The result is a topside design with radiative fins that is much more effective at removing heat from the system.

OpenROV Trident
Computer rendering of new WiFi Topside Module (physical parts are being manufactured now)

We’ve been doing lots of empirical testing with prototypes of the new design and so far it seems that our thermal budget is now a lot more in check than it was previously. Additionally, we’ve increased the thickness of the WiFi Topside so that it will float should it ever inadvertently get pulled into the water.

You may also notice that there is now a small rubber flap on the new Topside just above the status lights:

OpenROV Trident
Rendering of waterproof cover for the USB port on the new WiFi Topside Module

This flap covers a USB port we’ve added which can be used for secondary network connections to devices such as smartphones or routers (via Ethernet to USB adapter). We added this port to help make the system more reliably updatable. It will also support network connections for live internet streaming and internet control once those features are ready. The details of this system are still being developed, but it’s something we think will add a lot of value and capability.

Even without a towable design, maximizing signal quality and range of the WiFi Topside Module has been a very high priority for us. We originally selected a WiFi radio that is commonly used for embedded systems that require wireless networking capabilities, and we were fairly happy with its performance during early tests in the lab. Once we started running the system through our field testing program, however, we found that in very populated places with lots of WiFi signals, our connection quality would diminish rapidly to the point of being almost unusable. The only practical way to increase the performance of the WiFi system was to switch to an entirely new radio that could support more advanced networking features, so that’s what we decided to do. Although this change has increased our Bill of Materials cost, it has proven to be more than worth it from a user experience standpoint. Trident’s WiFi Topside Module now features a dual-band (2.4GHz + 5GHz) radio that has significantly more computing power than before and a greatly increased range. It is impossible to say what the exact range of any given radio system is because that depends on many external factors, but we expect the system to now work dependably even when it is in populated areas, and we expect the range to be comparable to that of a good home WiFi router when out in the field. Our goal is to build a system that works solidly in demanding field conditions, and the new WiFi Topside Module we've designed is an important part of that.

We should have a lot to talk about in our next update. Over the course of the next few weeks, we are expecting to receive the final parts for the first DVT production run of Trident, including injection molded parts, motors, batteries, cameras, and motherboards. Getting everything to line up has been no easy task from a project management standpoint - even as this is being typed many of us are busy traveling to factory floors to inspect the production process of each subsystem. What we’ve learned so far is that many of our suppliers are as enthusiastic about the product as we are. We have the advantage of building something really cool, and that has made it much easier to work with people when things get challenging.

So far, everything is still on track to start our DVT run next month. We plan to start shipping Tridents shortly after - beginning with Kickstarter pledges and followed by pre-orders in the order they were received.

One last thing… for those of you in the Bay Area who just can’t wait to try flying a Trident, we are at Bay Area Maker Faire this weekend with several Trident prototypes available to fly! Piloting in a small pool may not do the vehicle justice the way a lake or an ocean would, but it will be a great opportunity to see how it feels to control the vehicle. We encourage you to stop by!

That’s it for now - we look forward to sending out another update with details about our first parts soon!

As always, thanks for your support,

Eric