Low Power Mode For Custom GPS Tracker

March 28, 2022 by Bryan Cockfield 19 Comments

GPS has been a game-changing technology for all kinds of areas. Shipping, navigation, and even synchronization of clocks have become tremendously easier thanks to GPS. As a result of its widespread use, the cost of components is also low enough that almost anyone can build their own GPS device, and [Akio Sato] has taken this to the extreme with efforts to build a GPS tracker that uses the tiniest amount of power.

This GPS tracker is just the first part of this build, known as the air station. It uses a few tricks in order to get up to 30 days of use out of a single coin cell battery. First, it is extremely small and uses a minimum of components. Second, it uses LoRa, a low-power radio networking method, to communicate its location to the second part of this build, the ground station. The air station grabs GPS information and sends it over LoRa networks to the ground station which means it doesn’t need a cellular connection to operate, and everything is bundled together in a waterproof, shock-resistant durable case.

[Akio Sato] imagines this unit would be particularly useful for recovering drones or other small aircraft that can easily get themselves lost. He’s started a crowdfunding page for it as well. With such a long battery life, it’s almost certain that the operator could recover their vessel before the batteries run out of energy. It could also be put to use tracking things that have a tendency to get stolen.

Vacuum “Tube” Might Replace GPS One Day

November 15, 2021 by Al Williams 27 Comments

GPS and similar satellite navigation systems changed everything. The modern generation is far less likely to have had to fold a service station map or ask someone for directions on the side of the road. But GPS isn’t perfect. You need to see the sky, for one thing. For another, an adversary could jam or take down your satellites. Even a natural disaster could temporarily or permanently knock out your access to the satellites.

The people at Sandia National Labs worry about things like that and they want to replace GPS with quantum accelerometers and gyroscopes. The problem: those things take expensive and bulky vacuum systems and lasers. Sandia, however, has had a sealed device about the size of an avocado that weighs about a pound that could possibly do the job. Their goal is to see it work without maintenance for four more years.

This is no ordinary vacuum tube, though. It is made of titanium and sapphire. By itself, the device doesn’t do much of anything, but it shows that rubidium can be contained in a sealed chamber with no additional pumping. These quantum sensors aren’t anything new, but a tiny self-contained cold-atom sensor can pave the way for putting these sensors in vehicles like ships, aircraft, and ground vehicles. Submarines, which don’t usually have a clear shot at the sky without floating an antenna, are also candidates for the new technology.

A navigation system based on this technology uses a laser to cool the subject atoms and then measures their movements. This allows very precise determination of acceleration and rotation which allows for a more precise inertial navigation system.

If you need a refresher on how GPS works, we can explain it. If you think the idea of a module containing rubidium is far-fetched, don’t forget you can already get them for precision clock work.

Gladys West Modelled The Earth So That We Can Have GPS

August 3, 2021 by Al Williams 19 Comments

The name Gladys West is probably unfamiliar, but she was part of creating something you probably use often enough: GPS. You wouldn’t think a child who grew up on a sharecropping farm would wind up as an influential mathematician, but perhaps watching her father work very hard for very little and her mother working for a tobacco company made her realize that she wanted more for herself. Early on, she decided that education was the way out. She made it all the way to the Naval Surface Warfare Center.

While she was there she changed the world with — no kidding — mathematics. While she didn’t single-handedly invent satellite navigation, her work was critical to the systems we take for granted today.

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Keep An Eye On Your Bike With This DIY GPS Tracker

May 14, 2021 by Lewin Day 31 Comments

Owning a bike and commuting on it regularly is a great way to end up with your bike getting stolen, unfortunately. It can be a frustrating experience, and it can be particularly difficult to track a bike down once it’s vanished. [Johan] didn’t want to be caught out, however, and thus built a compact GPS tracker to give himself a fighting chance to hang on to his ride.

It’s built around the Arduino MKR GSM, a special Arduino built specifically for Internet of Things project. Sporting a cellular modem onboard, it can communicate with GSM and 3G networks out of the box. It’s paired with the MKR GPS shield to determine the bike’s location, and a ADXL345 3-axis accelerometer to detect movement. When unauthorised movement is detected, the tracker can send out text messages via cellular connection in order to help the owner track down the missing bike.

The tracker goes for a stealth installation, giving up the deterrent factor in order to lessen the chance of a thief damaging or disabling the hardware. It’s a project that should give [Johan] some peace of mind, though of course knowing where the bike is, and getting it back, are two different things entirely. We’ve seen creative techniques to build trackers for cats, too. It used to be the case that such “tracking devices” were the preserve of movies alone, but no longer. If you’ve got your own build, be sure to let us know on the tipline!

Open Source Pizza Compass Will Show You The Way

April 28, 2021 by Tom Nardi 18 Comments

In Pirates of the Caribbean, Captain Jack Sparrow has an enchanted compass that points to what the holder wants most in life. The Pizza Compass created by [Joe Grand] is basically the same thing, except it’s powered by a Particle Boron instead of a voodoo spell. Though depending on who’s holding the thing, we imagine they’d even point in the same direction.

[Joe] was tasked by Wired to design and produce the Pizza Compass in three weeks, a process which was documented in the video below. Being the Badgelife luminary that he is, the final product looks far more attractive than it has any business being. In addition to the Particle Boron that slots in on the back of the handheld PCB, there’s a GlobalTop PA6H GPS module, a LSM303DLHC compass, and eight NeoPixels that correspond to the points on the silkscreen compass.

Using the device is simple, just press the button and then walk around trying to keep the top-most LED lit. Behind the scenes, the Boron is pulling down the coordinates of the closest pizza place as reported by Google’s API, and comparing that to the user’s current GPS location. In practice that means the Pizza Compass isn’t concerned with nuances like streets or buildings, so its up to the user to figure out how best to stay on the desired heading. So rather than just following some turn-by-turn directions, there’s some proper navigation involved if you want that fresh slice.

If you don’t like pizza, you could reprogram the compass to point to whatever quest-worthy resource you wish. As explained at the end of the video, [Joe] wanted this to be an open source project so it could easily be adapted for different tasks by the community. Though honestly, it’s pretty weird if you don’t like pizza.

We’ve actually covered a very similar device in the past that would point the user to the closest White Castle or Five Guys, but with all due respect to that project, the Pizza Compass is in another league. When you’ve got the talent and experience of [Joe Grand] on the team, even the most mundane of gadgets ends up looking like a piece of art.

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High-Altitude Balloon Tracker Does Landing Prediction With Pi Pico

March 10, 2021 by Donald Papp 1 Comment

[Dave Akerman]’s ongoing high altitude balloon (HAB) work is outstanding, and we’re all enriched by the fact that he documents his work like he does. Recently, [Dave] wrote about his balloon tracker based on the Raspberry Pi Pico, whose capabilities brought a couple interesting features to the table.

In a way, HAB trackers have a fairly simple job: read sensors such as GPS and constantly relay that data to someone on the ground so that the balloon’s location can be tracked, and the hardware recovered when it ultimately returns to Earth. There are a lot of different ways to do this tracking, and one thing [Dave] enjoys is getting his hands on a new board and making a HAB tracker out of it. That’s exactly what he has done with the Raspberry Pi Pico.

Nothing builds familiarity like actually using a part, and the Pico had some useful things to contribute to a HAB tracker application. For one thing, the Pico has an onboard buck-boost converter that allows it to be powered from a relatively wide voltage range (~1.8 V to 5.5 V), so running it directly from batteries is both possible and desirable from a tracker perspective. But a really useful feature was possible thanks to the large amount of memory on the Pico: dynamic landing prediction.

[Dave] does landing prediction prior to launch based on environmental conditions, but it’s always better if the HAB tracker can also calculate its own prediction based on actual observed events and conditions. A typical microcontroller board like an Arduino doesn’t have enough memory to store the required data upon which to do such calculations, but the Pico does so easily. [Dave]’s new board transmits an updated landing site prediction along with all the rest of the telemetry, making the retrieval process much more reliable.

Want to see a completely different approach to HAB recovery? Check out a payload guided by steerable parachutes.

Reliable Frequency Reference From GPS

February 28, 2021 by Bryan Cockfield 35 Comments

GPS technology is a marvel of the modern world. Not only can we reliably locate positions on the planet with remarkable accuracy and relatively inexpensive hardware, but plenty of non-location-based features of the technology are available for other uses as well. GPS can be used for things like time servers, since the satellites require precise timing in order to triangulate a position, and as a result they can also be used for things like this incredibly accurate frequency reference.

This project is what’s known as a GPSDO, or GPS-disciplined oscillator. Typically they use a normal oscillator, like a crystal, and improve its accuracy by pairing it with the timing signal from a GPS satellite. This one is a standalone model built by [Szabolcs Szigeti] who based the build around an STM32 board. The goal of the project was purely educational, as GPSDOs of various types are widely available, but [Szabolcs] was able to build exactly what he wanted into this one including a custom power supply, simple standalone UI, and no distribution amplifier.

The build goes into a good bit of detail on the design and operation of the device, and all of the PCB schematics and source code are available on the projects GitHub page if you want to build your own. There are plenty of other projects out there that make use of GPS-based time for its high accuracy, too, like this one which ties a GPS time standard directly to a Raspberry Pi.