2025 Pet Hacks Contest: Loko Tracks Fido With LoRa And GPS

Some projects start as hacks, and end as products — that’s the case for [Akio Sato]’s project Loko, the LoRa/GPS tracker that was entered in our 2025 Pet Hacks Contest. The project dates all the way back to 2019 on Hackaday.io, and through its logs you can see its evolution up to the announcement that Loko is available from SeeedStudio.

It’s not a device necessarily limited to pets. In fact, the original use case appears to have been a backup locator beacon for lost drones. But it’s still a good fit for the contest none-the-less: at 12 grams, the tiny tracking device won’t bother even the most diminutive of pups, and will fit on any collar at only 30 mm x 23 mm. The “ground station” that pairs with your phone is a bit bigger, of course, but unless you have a Newfoundlander or a St. Bernard you’re likely bigger than fido. The devices use LoRa to provide a range up to 15 km — maybe better if you can loop them into a LoRaWAN. Depending on how often you pin the tracker, it can apparently last for as long as 270 days, which we really hope you won’t need to track a missing pet.

The hardware is based around Seeed’s Wio-E5 LoRa chip, which packages an STM32 with a LoRA radio. The firmware is written in MicroPython, and everything is available via GitHub under the MIT license. Though the code for the mobile app that interfaces with that hardware doesn’t appear to be in the repository at the moment. (There are folders, but they’re disappointingly empty.) The apps are available free on the iOS App Store and Google Play, however.

There’s still plenty of time to submit your own hacks to the Pet Hacks Contest, so please do! You have until May 10th, so if you haven’t started yet, it’s not too late to get hacking.

DIY Yagi Antenna Sends LoRa Signals Farther

LoRa gear can be great for doing radio communications in a light-weight and low-power way. However, it can also work over great distances if you have the right hardware—and the right antennas in particular. [taste_the_code] has been experimenting in this regard, and whipped up a simple Yagi antenna that can work at distances of up to 40 kilometers.

The basic mathematics behind the Yagi antenna are well understood. To that end, [taste_the_code] used a simple online calculator to determine the correct dimensions to build a Yagi out of 2 mm diameter wire that was tuned for the relevant frequency of 868 MHz. The build uses a 3D printed boom with holes for inserting each individual wire element in the right spot—with little measuring required once the wires are cut, since the print is dimensionally accurate. It was then just a matter of wiring it up to the right connector to suit the gear.

The antenna was tested with a Reyas RYLR998 module acting as a base station, with the DIY Yagi hooked up to a RYLR993 module in the field. In testing, [taste_the_code] was able to communicate reliably from 40 kilometers away.

We’ve featured some other unique LoRa antenna builds before, too.

Continue reading “DIY Yagi Antenna Sends LoRa Signals Farther”

Taylorator Makes Mischief On The Airwaves

[Stephen] recently wrote in to share his experiments with using the LimeSDR mini to conduct a bit of piracy on the airwaves, and though we can’t immediately think of a legitimate application for spamming the full FM broadcast band simultaneously, we can’t help but be fascinated by the technique. Called the Taylorator, as it was originally intended to carpet bomb the dial with the collected works of Taylor Swift on every channel, the code makes for some interesting reading if you’re interested in the transmission-side of software defined radio (SDR).

The write-up talks about the logistics of FM modulation, and how quickly the computational demands stack up when you’re trying to push out 100 different audio streams at once. It takes a desktop-class CPU to pull it off in real-time, and eats up nearly 4 GB of RAM.

You could use this project to play a different episode of the Hackaday Podcast on every FM channel at once, but we wouldn’t recommend it. As [Stephen] touches on at the end of the post, this is almost certainly illegal no matter where you happen to live. That said, if you keep the power low enough so as not to broadcast anything beyond your home lab, it’s unlikely anyone will ever find out.

Continue reading “Taylorator Makes Mischief On The Airwaves”

Before GPS There Was LORAN

We found it nostalgic to watch [ve3iku] fire up an old Loran-A receiver and, as you can see in the video below, he got it working. If you aren’t familiar with LORAN, it was a common radio navigation technique before GPS took over everything.

LORAN — an acronym for Long Range Navigation — was a US byproduct of World War II and was similar in many ways to Britain’s Gee system. However, LORAN operated at lower frequencies to improve its range. It was instrumental in helping convoys cross the Atlantic and also found use in the Pacific theater.

Continue reading “Before GPS There Was LORAN”

A LoRa Rain Gauge From The Ground Up

It’s a fair bet that most of us have a ton of wireless doo-dads around the house, from garage door remotes to wireless thermometers. Each of these gadgets seems to have its own idea about how to encode data and transmit it, all those dedicated receivers seem wasteful. Wouldn’t it be great to use existing RF infrastructure to connect your wireless stuff?

[Malte Pöggel] thinks so, and this LoRa rain gauge is the result. The build starts with a commercially available rain transmitter, easily found on the cheap as an accessory for a wireless weather station and already equipped with an ISM band transmitter. The rain-collection funnel and tipping-bucket mechanism were perfectly usable, and the space vacated by the existing circuit boards left plenty of room to play, not to mention a perfectly usable battery compartment. [Malte] used an ATmega328P microcontroller to count the tipping of the bucket, either through the original reed switch or via Hall Effect or magnetoresistive sensors. An RFM95W LoRa module takes care of connecting into [Malte]’s LoRaWAN gateway, and there’s an option to add a barometric pressure and temperature sensor, either by adding the BMP280 chip directly to the board or by adding a cheap I2C module, for those who don’t relish SMD soldering.

[Malte] put a lot of work into power optimization, and it shows. A pair of AA batteries should last at least three years, and the range is up to a kilometer—far more than the original ISM connection could have managed. Sure, this could have been accomplished with a LoRa module and some jumper wires, but this looks like a fantastic way to get your feet wet in LoRa design. You could even print your own tipping bucket collector and modify the electronics if you wanted.

Tiny LoRa GPS Node Relies On ESP32

Sometimes you need to create a satellite navigation tracking device that communicates via a low-power mesh network. [Powerfeatherdev] was in just that situation, and they whipped up a particularly compact solution to do the job.

As you might have guessed based on the name of its creator, this build is based around the ESP32-S3 PowerFeather board. The PowerFeather has the benefit of robust power management features, which makes it perfect for a power-sipping project that’s intended to run for a long time. It can even run on solar power and manage battery levels if so desired. The GPS and LoRa gear is all mounted on a secondary “wing” PCB that slots directly on to the PowerFeather like a Arduino shield or Raspberry Pi HAT. The whole assembly is barely larger than a AA battery.

It’s basically a super-small GPS tracker that transmits over LoRa, while being optimized for maximum run time on limited power from a small lithium-ion cell. If you’re needing to do some long-duration, low-power tracking task for a project, this might be right up your alley.

LoRa is a useful technology for radio communications, as we’ve been saying for some time. Meanwhile, if you’ve got your own nifty radio comms build, or anything in that general milleu, don’t hesitate to drop us a line!

WiFi Meets LoRa For Long Range

What do you get when you cross WiFi and LoRa? Researchers in China have been doing this, and they call the result WiLo. They claim to get reliable connections over about half a kilometer. Typical WiFi runs 40 to 60 meters, barring any Pringle’s cans or other exotic tricks.

According to [Michelle Hampson] writing in IEEE Spectrum, the researchers manipulated Wi-Fi’s OFDM multiplexing to emulate LoRa’s chirp-spreading signal. The advantage is that existing WiFi hardware can use the protocol to increase range.

Continue reading “WiFi Meets LoRa For Long Range”