from the earth-control-to-major-tom dept.
Arthur T Knackerbracket has processed the following story:
If you have devices out in the field, you probably want to connect with them. There was a time when that was hard to do, requiring telephone wires or specialized radio gear. Now cellular data is prevalent, but even cellular isn’t everywhere. If you have the cash, you can pay a number of satellite companies to carry your data, but that’s generally pricey and has its own challenges.
The age of satellite constellations is changing that. Of course everyone by now has heard of Starlink which is offering satellite internet via numerous satellites that are much smaller than traditional telecom satellites. But they’re not the only came[sic] in town.
A company called Swarm has put up a constellation of 1/4U cube satellites in low orbits. They offer a ground station that uses an omni antenna and a subscription access program for small amounts of data. They sent us a unit to review, and while I haven’t used the system in a real project yet, the kit was pretty impressive.
The Swarm “tile” is a tiny radio that can talk bi-directionally with small satellites in low Earth orbit. The little unit is made to mount on a PCB, can control its power consumption, and talks to your system via a standard 3.3V UART connection. It does, however, require a small antenna and maybe even a smaller antenna for its GPS module. Small, in this case, is about a mid-size handy talkie antenna. There is a half-wave antenna that doesn’t need a ground plane and a shorter antenna that does need a ground plane.
The system can get away with the small antenna because the satellites are in low Earth orbit. However, that also means you don’t always have a satellite overhead. The company claims they will eventually have more coverage but even then, the tile may hold on to your data until it finds a satellite. So for real-time data, this is probably not your answer.
Since these devices are made to go into the field, battery life is often a concern. According to the manual, the device uses up to 1A when transmitting, and up to 35mA on receive. In standby mode, the power draw drops to .022mA.
The tile itself costs just over $100. Then there’s the service. For $60 a year you get 750 data packets per device per month. Each packet can hold up to 192 bytes per packet. That’s enough for two packets a day for even the longest months. Of course, if you need more data or you need more frequent access, that’s something else. You can stack up to 4 data plans on one device, so $20 per month would get you 3,000 packets per month.