Have you ever been on a dive with your Trident and wished you could share your experience with someone across the world? We definitely have. It’s rare that you find great dive sites near a strong WiFi signal so we’ve come up with this guide on how to use a 4G LTE mobile router to stream live video from the Trident Underwater Drone to the internet. We've seen some great dive sites around the world with "full bars" and coverage maps growing quickly these days we have high hopes for the future of live-streaming from underwater with your drone.
Trident was designed using standard networking infrastructure and ports so that it can be used in tandem with existing infrastructure. This guide focuses on taking advantage of this architecture to stream your pilot screen live over 4G. It works best when you are diving in an area with strong 4G LTE signal and when your audience has a strong internet connection such as at home, in the office, or in a classroom.
When planning your dives, consider that for some 4G bandwidth can be pretty expensive. We typically use about 30 MB per minute of streaming. A full hour dive would end up being around 2 GB.
Under normal operation, Trident uses WiFi to connect directly to an Android device. In this case, we are setting up second network that is connected to both your Android device and your Trident. For this to work, Trident needs to be connected to a router directly with an Ethernet cable. You will need the following items to get started:
A 4G LTE Mobile Router
You will need a 4G LTE router that has WiFi and an Ethernet port, preferably with its own battery power. It also helps to have jacks for external antennas for low-signal areas. We recommend the Netgear Nighthawk M1 Gigabit LTE Mobile Router which works very well for this and is under $250 on Amazon.
You will need to have a data plan and an accompanying SIM card. We purchased our Nighthawk M1 through AT&T and using our existing data plan. The Nighthawk M1 can be purchased "unlocked" as well. If you plan on using this internationally it's important to get the router that works in your location. It's unclear whether models made for sale in one location will work in another. To be sure you can find one that works, you can use this reference page.
Pro tip— if you know where you want to dive, check out the OpenSignal App for maps of coverage (that are crowd-sourced). You can find which carrier might be stronger in a given area.
USB to Ethernet Adapter
You will also need a USB to Ethernet adapter and an Ethernet cable. A word of caution here: an adapter can use a few different embedded chip that require its own drivers, some of which aren't supported on the Trident Topside.
One of the most common chips used by these adapters is the RTL8152, which is supported. There are likely others that do work, but we have not tested them. Note that the RTL8153 may not work as it is a USB3.0 based device and the RTL8152 is designed for USB2.0.
The CableCreations CD0131 is one of the ones that is confirmed to work.
Streaming App Installed on Your Device
More on this below, but it’s good to have the streaming an app installed, tested, and ready to go before you get to the field.
The Latest OpenROV Cockpit App and Trident Software/Firmware
Head over to our blog post about how to update your app and accompanying software/firmware.
The order of operations is important for success. Following these instructions closely will help minimize errors.
The only out-of-the-box setting we needed to change on our Nighthawk M1 was to disable the option for the Ethernet connection to go into “standby” mode if it was not active. Other than that we were good to go. If you are configuring your own mobile router, some basic guidelines are:
Peel up the rubber USB cover on the Topside to reveal a USB port. Connect the USB to Ethernet adapter to the Topside. Connect the Ethernet cable to the adapter and to the Ethernet port in the mobile router. A diagram of this is shown below.
Once all of the cables are connected, turn on your mobile router. Wait a minute and then turn on Trident by connecting the tether to the tether port as normal. After a normal boot up routine, you should see only two of the three of the green LEDs on the topside light up.
Be careful to keep any water from splashing onto the topside when the rubber USB port protector is not in place as this keeps the Trident Topside water resistant.
Turn on your Android device and connect to your mobile router’s WiFi network. Make sure to NOT connect to the Trident WiFi network as you would usually (should be something like TRIDENT-ABCD).
Make sure mobile data and Bluetooth are off.
After connecting to your mobile router’s WiFi, check to see if your Android device has a decent internet connection. You can run a speed test or use an app.
Open the OpenROV Cockpit App. You should be able to pilot your Trident normally. If you cannot see or connect to your Trident as usual, you may have an issue somewhere. The best fix is to power-down Trident, check the physical connections, and start it again. You can log into the mobile router’s manager / admin console and see if Trident is connected on the LAN (wired connection) and is assigned an IP address correctly. When everything is working properly you will see two devices connected representing the Trident system. Your Android device should appear connected via wireless and be assigned an IP address on the same network.
Since we’re basically streaming our Android device’s screen, finding an app that will do this isn’t too difficult and it’s important to pick one that suits your needs and your audience. Our two favorites are below and we will add others as they become vetted
Twitch (at the time of writing this) is not able to stream your Android screen directly. We used Streamlabs as a workaround and found it to be really great. Twitch is designed for streaming games so there’s a buffer that creates a few-second delay but smooths out the video tremendously. This is important if there’s poor connectivity on the viewer’s side. The audio is good and we were able to send and receive chat messages through the app as well. Streamlabs has a good number of advanced features and also streams to YouTube.
If you’re streaming to Twitch, make sure you have two-factor authentication turned on for your Twitch account.
Pros: Smooth video, flexibility, good audio, built-in chat, and multi-platform streaming.
Cons: Not as intuitive or fast to get started, long delay.
Best used for: Streaming a dive as a one-way broadcast to a dispersed audience.
The Zoom Cloud Meetings app was really easy to get started. The screen sharing was quick and intuitive and we were able to invite people relatively easily. A lot of people are already familiar with the webinar / web conferencing interface and terminology so it didn’t take a lot to get the whole Sofar office watching quickly. A big disadvantage, however, was a choppy video for those with bad internet connection on the client side. This would get worse with a bad 4G connection as well. The upside is that you can give the microphone or video screen to participants really easily and without any delays.
Pros: Low latency, ability to switch between users for audio / video, easy to use, can send out calendar invites.
Cons: Choppy video, difficult to share link while streaming.
Best used for: Creating a webinar for a targeted audience that will contribute or participate with audio and/or video.