Adding Variometer Functionality To A GPS

May 25, 2023 by Bryan Cockfield 10 Comments

Flying a glider, or similarly piloting a paraglider or hang glider, can all be pathways into aviation with a lower barrier of entry than powered flight. Sacrificing one’s engine does generate a few complexities, but can be rewarding as the pilot searches for various means of increasing altitude like ridge soaring or thermaling. You’ll need a special instrument called a variometer to know just how much altitude you’re gaining though, like this one which is built into commercially-available handheld GPS units.

These GPS units are normally intended for use on terra firma only, but [Oganisyan] has figured out a clever way to add this flight instrumentation to these units to help when operating a paraglider. An ATmega328 paired with a pressure sensor is added to the inside of the GPS units and communicates with an available serial interface within the units. To complete the modification, a patched firmware must be installed which adds the variometer function to the display. This upgrade is compatible with a handful of GPS units as well such as the BikePilot2+ or Falk Tiger.

For those who already own one of these GPS units, this could be a cost-effective way of obtaining a variometer, especially since commercially-available variometers tailored for this sort of application can cost around $200 to $500. It is an activity sensitive to cost, though, as it offers a much more affordable option for taking to the skies than any powered craft could, with an exception made for this powered paraglider which offers the ability for powered take off and flight extension using electric-powered props.

Thanks to [MartinO] for the tip!

A ginger cat, wearing a blue harness with a brass and wooden box on its back

Handmade GPS Tracker Keeps An Eye On Adventurous Cats

January 31, 2023 by Robin Kearey 27 Comments

One of the most convenient things about having cats is their independent lifestyle: most are happy to enjoy themselves outside all day, only coming back home when it’s time for dinner and a nap. What your cat gets up to during the day remains a mystery, unless you fit it with a GPS collar. When [Sahas Chitlange] went searching for a GPS tracker for his beloved Pumpkin, he found that none were exactly to his liking: too slow, too big, or simply unreliable. This led him to design and build his own, called Find My Cat.

Continue reading “Handmade GPS Tracker Keeps An Eye On Adventurous Cats” →

A bike computer sits on a wooden background. The back of the bike computer has a 3D printed attachment with two white translucent zip ties running through the back.

Repairing A Bike GPS With 3D Printing

October 7, 2022 by Navarre Bartz 10 Comments

We love hacks that keep gadgets out of the trash heap, and [Brieuc du Maugouër] has us covered with this 3D printable replacement mount he designed for his bike GPS.

One of the most frustrating ways a gadget can fail is when a small, but critical part of the device fails. [du Maugouër] combined a 3D printed back and four M2x6mm screws to make a robust new mount to replace the broken OEM mount on his handlebar-mounted GPS. Slots for zip tie mounting are included in case the replacement mount breaks before yet another replacement can be printed. Apparently [du Maugouër] agrees with Chief O’Brien that “in a crunch, I wouldn’t like to be caught without a second backup.” [Youtube]

It’s exciting that we’re finally in a time when 3D printed replacement parts are living up to their potential. This would be a lot easier if more manufacturers posted 3D printed design files instead of getting them pulled from 3D file platforms, but makers will find a way regardless of OEM approval.

We’ve covered a lot of bike hacks over the years including DIY Bike Computers and GPS Trackers. Do you have a project that keeps something from becoming trash or might save the world another way? There’s still time to enter the Save the World Wildcard round of the Hackaday Prize (closes October 16th).

TickTag, a tiny GPS logger with 3d printed case, LiPo battery and a 1 Euro coin for size reference

Tiny GPS Logger For The Internet Of Animals

September 18, 2022 by Abe Connelly 35 Comments

[Trichl] has created a tiny GPS logger, called ‘TickTag’, designed as an inexpensive location tracking option for animal studies. The low cost, tiny form factor, and large power density of the LiPo battery give it the ability to track large populations of small animals, including dogs and bats.

The TickTag is capable of getting 10,000 GPS fixes from its 30 mAh cell. Each unit is equipped with an L70B-M39 GPS module controlled by an Atmel ATtiny1626 microcontroller and sports a tiny AXE610124 10-pin connection header for programming and communication. GPS data is stored on a 128 kB EEPROM chip with each GPS location fix using 25 bits for latitude, 26 bits for longitude, and 29 bits for a timestamp. Add it all up and you get 10 bytes per GPS data point (25+26+29=80), giving the 10k GPS fix upper bound.

To record higher quality data and extend battery life, the TickTag can be programmed to record GPS location data using variable frequency intervals or when geofencing bounds have been crossed.

Continue reading “Tiny GPS Logger For The Internet Of Animals” →

A GPS Frequency Standard For When The Timing Has To Be Right

June 29, 2022 by Jenny List 10 Comments

A metrology geek will go to extreme lengths to ensure that their measurements are the best, their instruments the most accurate, and their calibration spot-on. There was a time when for time-and-frequency geeks this would have been a difficult job, but with the advent of GPS satellites overhead carrying super-accurate atomic clocks it’s surprisingly easy to be right on-frequency. [Land-boards] have a GPS 10 MHz clock that’s based around a set of modules.

Since many GPS modules have a 10 MHz output one might expect that this one to simply hook a socket to the module and have done, but instead it uses another of their projects, a fast edge pulse generator with the GPS output as its oscillator, as a buffer and signal conditioner. Add to that an QT Py microcontroller board to set up the GPS, and there you have a standalone 10 MHz source to rival any standard. Full details can be found on the project’s wiki, and the firmware can be found on GitHub.

Careful with your exploration of standard frequencies, for that can lead down a rabbit hole.

Around GPS In 100 Videos

June 23, 2022 by Al Williams 9 Comments

Do you know what the IODC word in GPS data means? If so, great! If not, head over to see the 32nd of [Michel van Biezen’s] 100-part video series on GPS. You probably want to watch the other 31 videos before he gets too much further ahead of you, too. [Michel] reminds you of that professor you had in college who knows a whole lot about something. In fact, scanning his YouTube channel, he knows a lot about many topics ranging from optics, chemistry, kalman filters, and lots of electronics.

There is a dedicated playlist for the GPS videos dating back to 2016. So 32 videos in about six years. So you might have a little time to catch up. While the first video is pretty introductory as you might expect, by the time you get to video 7 the topics switch to things like the C/A code, BPSK, and gory details of all the frame data, including the IODC word.

Continue reading “Around GPS In 100 Videos” →

Hackaday Podcast 170: Poop Shooting Laser, Positron Is A 3D Printer On Its Head, DIY Pulsar Capture, GPS’s Achilles Heel

May 27, 2022 by Tom Nardi 1 Comment

Join Hackaday Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi for a recap of all the best tips, hacks, and stories of the past week. We start things off with an update on Hackaday’s current slate of contests, followed by an exploration of the cutting edge in 3D printing and printables. Next up we’ll look at two achievements in detection, as commercial off-the-shelf hardware is pushed into service by unusually dedicated hackers to identify both dog poop and deep space pulsars (but not at the same time). We’ll also talk about fancy Samsung cables, homebrew soundcards, the surprising vulnerability of GPS, and the development of ratholes in your cat food.

Direct Download link

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!