With a GPS on every smartphone, one would be forgiven for forgetting that handheld GPS units still exist. Seeking to keep accurate data on a few upcoming trips, [_Traveler] took on a custom-build that resulted in this GPS data logger.
Keeping tabs on [_Traveler] is a Ublox M8N GPS which is on full-time, logging data every 30 seconds, for up to 2.5 days. All data is saved to an SD card, with an ESP32 to act as a brain and make downloading the info more accessible via WiFi . While tracking the obvious — like position, speed, and time — this data logger also displays temperature, elevation, dawn and dusk, on an ePaper screen which is a great choice for conserving battery.
The prototyping process is neat on this one. The first complete build used point-to-point soldering on a protoboard to link several breakout modules together. After that, a PCB design embraces the same modules, with a footprint for the ESP’s castellated edges and header footprints for USB charing board, SD card board, ePaper, etc. All of this finds a hope in a 3D printed enclosure. After a fair chunk of time coding in the Arduino IDE the logger is ready for [_Traveler]’s next excursion!
As far as power consumption in the field, [_Traveler] says the GPS takes a few moments to get a proper location — with the ESP chewing through battery life all the while — and plans to tinker with it in shorter order.
Here’s something really wonderful. [Dave Akerman] wrote up the results of his attempt to use a high-altitude balloon to try to re-create a famous image of NASA’s Bruce McCandless floating freely in space with the Earth in the background. [Dave] did this in celebration of the 34th anniversary of the first untethered spacewalk, even going so far as to launch on the same day as the original event in 1984. He had excellent results, with plenty of video and images recorded by his payload.
Adhering to the actual day of the spacewalk wasn’t the only hurdle [Dave] jumped to make this happen. He tracked down an old and rare “Astronaut with MMU” (Mobile Maneuvering Unit) plastic model kit made by Revell USA and proceeded to build it and arrange for it to remain in view of the cameras. Raspberry Pi Zero Ws with cameras, LoRA hardware, action cameras, and a UBlox GPS unit all make an appearance in the balloon’s payload.
Sadly, [Bruce McCandless] passed away in late 2017, but this project is a wonderful reminder of that first untethered spacewalk. Details on the build and the payload, as well as the tracking system, are covered here on [Dave]’s blog. Videos of the launch and the inevitable balloon burst are embedded below, but more is available in the summary write-up.
The Talking Clock service is disappearing, and it’s quite possible that few of you will be aware of its passing. One of the staples of twentieth-century technology, the Talking Clock service was the only universally consumer-available source of accurate time information away from hourly radio time signals in the days before cheap radio-controlled clocks, or GPS. You’d dial (on a real dial, naturally!) a telephone number, to be greeted with a recorded voice telling you what the time would be at the following beep. Clocks were set, phone companies made a packet, and everybody was happy with their high-tech audio horology.
At its heart is a SkyTraq Venus838LPx miniature GPS module coupled to an ATMega32E5 microcontroller. The speech comes in the form of pre-recorded samples stored on an SD card. There is a small on-board amplifier to drive a single speaker. For extreme authenticity perhaps it could be attached to a GSM mobile phone module to provide a dial-up service, but he’s got everything he needs for a New Years Eve.
Want to hear what that that bit of nostalgia sounded like? Check out the quick clip below. As for modern replacements, we’ve had at least one talking clock here in the past, but not one using GPS.
We get a lot of awesome projects sent our way via the tip line. Well, mainly it seems like we get spam, but the emails that aren’t trying to sell us something are invariably awesome. Even so, it’s not often we get a tip that contains the magic phrase “determine Mach number” in its list of features. So to say we were interested in the Asgard Air Data Computer (ADC) is something of an understatement.
Now we’ll admit right up front: we aren’t 100% sure who the target audience for the Asgard is, but it certainly looks impressive. Team member [Erik] wrote into tip line with information about this very impressive project, which is able to perform a number of measurements on incoming air, such as true speed, viscosity, and temperature. The team says it has applications ranging from HVAC to measuring the performance of bicycles. We don’t know who’s going so fast on their bike that they need to measure air speed, but of course the hacker community never ceases to amaze us.
Even if you don’t have a jet fighter that could benefit from a high performance ADC such as Asgard, you have to be impressed by the incredible work the team has done not only designing and building it, but documenting it. From the impeccably designed 3D printed case to the stacked PCB internals, every aspect of Asgard screams professional hardware.
Data collected from Asgard can be stored on the internal micro SD if the device is to be used in stand-alone mode, or you can connect to it over USB or Bluetooth thanks to the HC-05 module. The team has even put together some scripts to merge the Asgard’s generated air data with GPS position information.
SpaceX just concluded 2017 by launching 10 Iridium NEXT satellites. A footnote on the launch was the “hosted payload” on board each of the satellites: a small box of equipment from Aireon. They will track every aircraft around the world in real-time, something that has been technically possible but nobody claimed they could do it economically until now.
Challenge one: avoid adding cost to aircraft. Instead of using expensive satcom or adding dedicated gear, Aireon listen to ADS-B equipment already installed as part of international air traffic control modernization. But since ADS-B was designed for aircraft-to-aircraft and aircraft-to-ground, Aireon had some challenges to overcome. Like the fact ADS-B antenna is commonly mounted on the belly of an aircraft blocking direct path to satellite.
Challenge two: hear ADS-B everywhere and do it for less. Today we can track aircraft when they are flying over land, but out in the middle of the ocean, there are no receivers in range except possibly other aircraft. Aireon needed a lot of low-orbit satellites to ensure you are in range no matter where you are. Piggybacking on Iridium gives them coverage at a fraction of the cost of building their own satellites.
The main components tucked inside of the 3D printed case of the locator are an Adafruit Trinket, a GPS receiver, and a compass module. The Adafruit NeoPixel Ring is of course front and center, serving as the device’s display. To power the device there’s an old battery, a LiPo charger circuit, and a 5V converter.
One of the goals for the project was that it could be constructed out of things [Sean] already had laying around, so some concessions had to be made. The Trinket ended up having too few pins, the compass lacks an accelerometer, and the switches and buttons are a bit clunky for the build. But in the end it comes together well enough to get the job done, and at least he was able to clear some stuff out of his parts bins.
To allow its owner to disassemble and potentially rebuild it into something else later, no soldered joints were used in the construction of the locator. Everything is done with jumper wires, which lead to some interesting problem solving such as using a strip of pin header as a bus bar of sorts. A bit of heat shrink over the bundle holds everything together and prevents shorts.
GPS jammers are easily available on the Internet. No, we’re not linking to them. Nevertheless, GPS jammers are frequently used by truck drivers and other people with a company car that don’t want their employer tracking their every movement. Do these devices work? Are they worth the $25 it costs to buy one? That’s what [phasenoise] wanted to find out.
These tiny little self-contained boxes spew RF at around 1575.42 MHz, the same frequency used by GPS satellites in high Earth orbit. Those signals coming from GPS satellites are very, very weak, and it’s relatively easy to overpower them with noise. That’s pretty much the block diagram for these cheap GPS jammers — put some noise on the right frequency, and your phone or your boss’s GPS tracker simply won’t function. Note that this is a very low-tech attack; far more sophisticated GPS jamming and spoofing techniques can theoretically land a drone safely.
[phasenoise]’s teardown of the GPS jammer he found on unmentionable websites shows the device is incredibly simple. There are a few 555s in there creating low-frequency noise. This feeds a VCO with a range of between 1466-1590 MHz. The output of the VCO is then sent to a big ‘ol RF transistor for amplification and out through a quarter wave antenna. It may be RF wizardry, but this is a very simple circuit.
The output of this circuit was measured, and to the surprise of many, there were no spurious emissions or harmonics — this jammer will not disable your cellphone or your WiFi, only your GPS. The range of this device is estimated at 15-30 meters in the open, which is good enough if you’re a trucker. In the canyons of skyscrapers, this range could extend to hundreds of meters.
It should be said again that you should not buy or use a GPS jammer. Just don’t do it. If you need to build one, though, they’re pretty easy to design as [phasenoise]’s teardown demonstrates.