If you want to listen to satellites, you have to be able to track them as they pass over the sky. When I first started tracking amateur satellites, computing the satellite’s location in the sky was a part of the challenge. Nowadays, that’s trivial. What’s left over are all the extremely important real-world details. Let’s take a look at a typical ham satellite tracking setup and see how it all ties together.
Rotators for Steering
The popularity of robotics, 3D printing, and CNC machines has resulted in a deluge of affordable electric motors and drivers. It’s hard to imagine that an electric motor for rotating an antenna would be anything special, but in fact, antenna rotators are non-trivial engineering designs. Most of the challenges are mechanical, not electrical — the antennas that they drive can be huge, have significant wind loading and rotational inertial, and just downright weigh a lot. A rotator design has to consider bearings, weather exposure, all kinds of loads, not just rotational. And usually a brake is required to keep the antenna pointed in windy conditions.
There’s been a 70-some year history of these mechanisms from back in the 1950s when Cornell Dubilier Electronics, the company you know as a capcacitor manufacturer, began making these rotators for television antennas in the 1950s. I was a little surprised to see that the rotator systems you can buy today are not very different from the ones we used in the 1980s, other than improved electronic controls. Continue reading “Tracking Satellites: The Nitty Gritty Details”
The smartphone is perhaps the signature device of our modern lives. For most of the population it is never more than an arm’s length away, it’s on your person more than any other device in your life. Smartphones are packed with all sorts of radios and ways to communicate wireless. [Amine Mansouri] built an ESP8266 based tracking device that takes advantage of this.
Most WiFi-enabled devices will send out “probe requests” frames trying to search for the SSIDs they were connected to. These packets contain the device MAC address as well as the SSIDs you’ve connected to. Using about 12 components, [Amine] laid out a small board in Eagle. By putting the ESP8266 in monitor mode, the probe frames can be logged and uploaded. The code can be updated OTA making it easy to service while in the field.
With permission from his local library, eight repeater boards were scattered throughout the building to forward the probe packets to where the tracker could pick them up. A simple web interface was built that allows the library to figure out how many people are in the library and how often they frequent the premises.
While an awesome project with open-source code on Github, it is important to stress how important is it to get permission to do this kind of tracking. While some phones implement MAC randomization, there are still many out in the wild that don’t. While this is similar to another project that listens to radio signals to determine the coming and going of ships and planes, tracking people with this sort of granularity is in a different category altogether.
Thanks [Amine] for sending this one in!
There’s a laundry list of ways that humans are polluting the earth, and even though it might not look like it from the surface, the oceans seem to bear the brunt of our waste. Some research suggests that plastic doesn’t fully degrade as it ages, but instead breaks down into smaller and smaller bits that will be somewhere the in environment for such a long time it could be characterized in layman’s terms as forever.
Not only does waste of all kinds make its way to the oceans by rivers or simply by outright dumping, but commercial fishing gear is estimated to comprise around 10% of the waste in the great blue seas, and one of the four nonprofits help guide this year’s Hackaday Prize is looking to eliminate some of that waste and ensure it doesn’t cause other problems for marine life. This was the challenge for the Conservation X Labs dream team, three people who were each awarded a $6,000 micro-grant to work full time for two months on the problem.
It isn’t about simply collecting waste in the ocean, but rather about limiting the time that potentially harmful but necessary fishing equipment is in the water in the first place. For this two-month challenge, this team focused on long lines used by professional fishing operations to attach buoys to gear like lobster pots or crab traps. These ropes are a danger to large ocean animals such as whales when they get tangled in them and, if the lines detach from the traps, the traps themselves continue to trap and kill marine life for as long as they are lost underwater. This “ghost gear” is harmful in many different ways, and reducing its time in the water or “soak time” was the goal for the project.
Let’s take a closer look at their work after the break, and we can also see the video report they filed as the project wrapped up.
Continue reading “Untethered: Fishing Without Lines”
Modern society has brought us all kinds of wonders, including rapid intercontinental travel, easy information access, and decreased costs for most consumer goods thanks to numerous supply chains. When those supply chains break down as a result of a natural disaster or other emergency, however, the disaster’s effects can be compounded without access to necessary supplies. That’s the focus of Field Ready, a nonprofit that sets up small-scale manufacturing in places without access to supply chains, or whose access has been recently disrupted.
As part of this year’s Hackaday Prize, a each of our four nonprofit partners outline specific needs that became the targets of a design and build challenge. Field Ready was one of those nonprofits, and for the challenge they focused on quality control for their distributed manufacturing system. We took a look at Field Ready back in June to explore some of the unique challenges associated with their work, which included customers potentially not knowing that a product they procured came from Field Ready in the first place, leading to very little feedback on the performance of the products and nowhere to turn when replacements are needed.
The challenge was met by a dream team whose members each received a $6,000 microgrant to work full time on the project. The’ve just made their report on an easier way of tracking all of the products produced, and identifying them even for those not in the organization. As a result, Field Ready has a much improved manufacturing and supply process which allows them to gather more data and get better feedback from users of their equipment. Join us after the break for a closer look at the system and to watch the team’s presentation video.
Continue reading “Quality Control, Done Anywhere”
We all know that version one of a project is usually a stinker, at least in retrospect. Sure, it gets the basic idea into concrete form, but all it really does is set the stage for a version two. That’s better, but still not quite there. Version three is where the magic all comes together.
At least that’s how things transpired on [Shane Wighton]’s quest to build the perfect basketball robot. His first version was a passive backboard that redirected incoming shots based on its paraboloid shape. As cool as the math was that determined the board’s shape, it conspicuously lacked any complicated systems like motors and machine vision — you know, the fun stuff. Version two had all these elaborations and grabbed off-target shots a lot better, but still, it had a limited working envelope.
Enter version three, seen in action in the video below. Taking a page from [Mark Rober]’s playbook, [Shane] built a wickedly overengineered CoreXY-style robot to cover his shop wall. Everything was built with the lightest possible materials to keep inertia to a minimum and ensure the target ends up in the right place as quickly as possible. [Shane] even figured out how to mount the motor that tilts the backboard on the frame rather than to the carriage. A Kinect does depth-detection duty on the incoming ball — or the builder’s head — and drains pretty much every shot it can reach.
[Shane] has been doing some great work automating away the jobs of pro athletes. In addition to basketball, he has tackled both golf and baseball, bringing explosive power to each. We’re looking forward to versions two and three on both of those builds as well.
Continue reading “Third Time’s A Charm For This Basketball-Catching Robot”
Flying a quadcopter or other drone can be pretty exciting, especially when using the video signal to do the flying. It’s almost like a real-life video game or flight simulator in a way, except the aircraft is physically real. To bring this experience even closer to the reality of flying, [Kevin] implemented stereo vision on his quadcopter which also adds an impressive amount of functionality to his drone.
While he doesn’t use this particular setup for drone racing or virtual reality, there are some other interesting things that [Kevin] is able to do with it. The cameras, both ESP32 camera modules, can make use of their combined stereo vision capability to determine distances to objects. By leveraging cloud computing services from Amazon to offload some of the processing demands, the quadcopter is able to recognize faces and keep the drone flying at a fixed distance from that face without needing power-hungry computing onboard.
There are a lot of other abilities that this drone unlocks by offloading its resource-hungry tasks to the cloud. It can be flown by using a smartphone or tablet, and has its own web client where its user can observe the facial recognition being performed. Presumably it wouldn’t be too difficult to use this drone for other tasks where having stereoscopic vision is a requirement.
Thanks to [Ilya Mikhelson], a professor at Northwestern University, for this tip about a student’s project.
High Altitude Balloons (HAB) are a great way to get all kinds of data and shoot great photos and video, but what goes up must come down. Once the equipment has landed, one must track it down. GPS and LoRA, with its long wireless range and ease of use, are invaluable tools in tracking payloads that have returned to Earth. [Dave Akerman] has made handheld receivers to guide him to payloads, but wanted something even smaller; ideally something that could be worn on the wrist.
One day he came across the affordable LilyGo T-Watch which includes GPS and LoRA functionality, and he started getting ideas. The watch has the features, but the stock firmware didn’t measure up. Not to be deterred, [Dave] wrote new firmware to turn the device into a wrist-worn GPS and LoRA chase watch.
Not only is the new firmware functional, but it’s got a wonderful user interface. GitHub repository for the new firmware is here, and you can see the UI in action in the brief video embedded below.
Continue reading “Custom Firmware Makes A LoRA-Enabled HAB Tracker Watch”