If you have equipment on site, you may want to connect to them. Once upon a time, this was difficult to do and required telephone lines or specialized radio equipment. Cellular data is common now, but even cellular data is not ubiquitous. If you have cash, you can pay some satellite companies to carry your data, but this is usually expensive and has its own challenges.
The era of satellite constellations is changing this. Of course, everyone has heard of Starlink now, which provides satellite Internet through many satellites much smaller than traditional telecommunications satellites. But they are not the only people in town.
A company called Swarm has been established A set of 1/4U CubeSats In low orbit. They provide ground stations using omnidirectional antennas and subscription access programs for small amounts of data.They send us Review unit, Although I have not used the system in actual projects, the kit is impressive.
The Swarm “tile” is a miniature radio that can communicate two-way with small satellites in low earth orbit. This small device is mounted on the PCB and can control its power consumption and communicate with your system through a standard 3.3V UART connection. However, its GPS module does require a small antenna, and may even require a smaller antenna. Small, in this case, is about a medium-sized portable walkie-talkie antenna. There is a half-wave antenna that does not require a ground plane and a shorter antenna that requires a ground plane.
The system can get rid of small antennas because the satellite is in low earth orbit. However, this also means that you don’t always have satellite overhead. The company claims that they will eventually have more coverage, but even then, the tiles may retain your data until a satellite is found. Therefore, for real-time data, this may not be your answer.
Since these devices are made to enter the field, battery life is often an issue. According to the manual, the device uses up to 1A when sending and 35mA when receiving. In standby mode, the power consumption is reduced to 0.022mA.
The cost of the tile itself is just over $100. Then there is service. At $60 per year, each device can get 750 data packages per month. Each data packet can hold up to 192 bytes. Even for the longest months, this is enough for two sachets a day. Of course, if you need more data or more frequent access, that’s another matter. You can stack up to 4 data plans on one device, so $20 per month can get you 3,000 data packages per month.
Not all data packets are created equal. You can have up to 10 downlink packets per day, and up to 60 of the 750 downlink packets allocated per month. So if you really need two-way, you should think about it carefully. Obviously, this is not the correct service. For example, a system for remotely controlling the liquid level of a storage tank needs to exchange two-way commands and data in real time multiple times per hour. But, for example, an alarm system that checks once a day, sends data packets when closed, and accepts infrequent commands to change the arming/disarming time may be suitable.
You see that the usual way for connecting devices to communicate via satellite is via VSAT (Very Small Aperture Terminal) with a 2-3 foot dish antenna. These tend to be expensive and very picky to set up. The advantage is that the satellite does not move, so once you set it up, that’s it (unless your antenna is moving). You can always access the satellite. Of course, delay is also important.
However, you can find VSAT almost anywhere. For example, stores use it to keep the point-of-sale terminal connected. Many lottery machines also use VSAT. Power companies and natural gas pipelines use VSAT to collect data from remote areas.
However, VSAT does not seem to be a direct competitor of Swarm. If you need a real network connection, you can’t really use Swarm. But if you only need a small amount of infrequently used data, Swarm may be much cheaper than VSAT terminals and easier to deploy. In our opinion, the real competitor is cheap cellular modems. Of course, cellular does no good to your data collection buoy in the middle of the ocean. So Swarm is not for everyone, but for some projects, it may be worth a look.
There are other companies trying to become the satellite provider of choice for IoT applications.Have Oktek, Aobo Communication, Kepler Communications, with fleet There is no doubt that there are other competitors. StarLink may also become a participant in this field, but so far, it has caused a sensation in providing Internet connectivity. There are also many traditional names, such as Hughes, GlobalStar and Iridium, which have some IoT products on the market, or at least have already announced them. However, compared to some other options, Swarm seems very friendly to hackers.
The evaluation kit is very rugged and is housed in a waterproof (IP68) enclosure with batteries, solar panels and ESP32 host. There is also a sturdy tripod. The price of $500 is not cheap, but the quality is shown, and it feels like it shouldn’t cost less.Have Installation video from the company If you are looking for more detailed information about the process.
There is a rubber dome switch to turn it on, and the OLED display shows some initial data. The SNR number and red LED on the display told me that the noise was too loud to successfully communicate with the satellite indoors, but sitting on the terrace, the light turned green. I did not install a tripod, which seems to be ok.
However, the green LED does not mean that the device is actually talking to the satellite. Fortunately, the predictor showed that I was almost two hours away from the passage of the satellite. The company said that by 2022, they plan to have all 92 satellites activated, which will give them “almost constant” coverage. However, once I installed the satellite overhead, everything went as you wished.
The evaluation kit has a serial connection to the ESP32, but because it is in a waterproof housing, it is easier to use WiFi. We noticed that WiFi has a limited range, which may be to reduce the noise of the satellite receiver.
The box will periodically send its GPS location and some other data, and use the web interface to send a short email, although it is obvious that this will eventually exhaust your data plan. By default, the data is displayed on the website, and you can get JSON from the web service. You can also view GPS data on the map, which is only interesting when you are moving.
Of course, everything is put on hold until you see a satellite above your head.You can enter your location into A website See when the upcoming pass is suitable for you.
If you communicate directly with the tile, you will find that it uses a NEMA style communication string, just like GPS.Obviously, there is Some unusual commands, But the data format is the same.
What will you use it for?
When you first start thinking about what you can do with satellite data, your imagination will go crazy. Then you have to go back to Earth-so to speak-when you realize that you have to strictly limit your data and you cannot expect it to be even close to real time.
I have a feeling that satellite data is one of the things that sounds better than most applications.If you are within range of a cellular network, then May be cheaper than you thinkHowever, for those applications that will go to without cell towers before, if you can live within its limits, Swarm may be the answer.