Building A Low-Cost Satellite Tracker

Looking up at the sky just after sunset or just before sunrise will reveal a fairly staggering amount of satellites orbiting overhead, from tiny cubesats to the International Space Station. Of course these satellites are always around, and even though you’ll need specific conditions to view them with the naked eye, with the right radio antenna and only a few dollars in electronics you can see exactly which ones are flying by at any time.

[Josh] aka [Ham Radio Crash Course] is demonstrating this build on his channel and showing every step needed to get something like this working. The first part is finding the correct LoRa module, which will be the bulk of the cost of this project. Unlike those used for most Meshtastic nodes, this one needs to be built for the 433 MHz band. The software running on this module is from TinyGS, which we have featured here before, and which allows a quick and easy setup to listen in to these types of satellites. This build goes much further into detail on building the antenna, though, and also covers some other ancillary tasks like mounting it somewhere outdoors.

With all of that out of the way, though, the setup is able to track hundreds of satellites on very little hardware, as well as display information about each of them. We’d always favor a build that lets us gather data like this directly over using something like a satellite tracking app, although those do have their place. And of course, with slightly more compute and a more directed antenna there is all kinds of other data beaming down that we can listen in on as well, although that’s not always the intent.

Continue reading “Building A Low-Cost Satellite Tracker”

Announcing The 2025 Hackaday Superconference Communicator Badge

It’s the moment you hard-core hardware nerds have been waiting for: the reveal of the 2025 Hackaday Supercon Communicator Badge. And this year, we’ve outdone ourselves, but that’s thanks to help from stellar collaboration with folks from the community, and help from sponsors. This badge is bigger than the sum of its parts, and we’ve planned for it to be useful for you to hack on in the afterlife. Indeed, as always, you are going to be the final collaborator, so we can’t wait to see what you’ll do with it.

We’re going out – wide out – on a limb and trying to create a dense mesh network of badges talking to each other at Supercon. It’s going to be like a badge-hosted collection of chat rooms, as connected as we can make them without talking over each other.

You look up a topic, say Retro Computing or SAO trading, punch in the channel number on the numpad, and your badge starts listening to everything going on around that topic. But they also listen to everything else, and repeat anything they hear on to their neighbors. Like IRC, but LoRa.

Continue reading “Announcing The 2025 Hackaday Superconference Communicator Badge”

A photo of the HAT with the LoRa module and relay visible on the top

LoRaSense Pi Hat Aims To Kick Start IoT Projects

[Avi Gupta] recently sent in their LoRaSense RGB Pi HAT project. This “HAT” (Hardware Attached to Top) is for any Raspberry Pi with 40-pin header. The core of the build is the custom printed circuit board which houses the components and interconnects. The components include an SHT31 temperature and humidity sensor, an SX1278 LoRa module, and a 10 amp 220 VAC relay. The interconnects include support for UART, I2C, SPI, and WS2812B RGB LED interfaces as well as a stackable header for daisy chaining HATs.

The attached components in combination support a wide range of use cases. Possible uses for this Raspberry Pi HAT include smart home systems, agricultural projects, industrial monitoring, smart greenhouse, remote weather stations, or alerting systems. You can detect weather conditions, send and receive information, switch mains powered loads, and use RGB LEDs for status and alerting.

If you’re interested in LoRa technology be sure to read about the Yagi antenna that sends LoRa signals farther.

Two For The Price Of One: BornHack 2024 And 2025 Badges

BornHack is a week-long summer hacker camp in a forest on the Danish island of Fyn, that consistently delivers a very pleasant experience for those prepared to make the journey. This year’s version was the tenth iteration of the camp and it finished a week ago, and having returned exhausted and dried my camping gear after a Biblical rainstorm on the last day, it’s time to take a look at the badges. In case you are surprised by the plural, indeed, this event had not one badge but two. Last year’s badge suffered some logistical issues and arrived too late for the camp, so as a special treat it was there alongside the 2025 badge for holders of BornHack 2024 tickets. So without further ado, it’s time to open the pack for Hackaday and see what fun awaits us. Continue reading “Two For The Price Of One: BornHack 2024 And 2025 Badges”

Hands On: The Hacker Pager

It should come as no surprise that the hacker community has embraced the Meshtastic project. It’s got a little bit of everything we hold dear: high quality open source software, fantastic documentation, a roll-your-own hardware ethos, and just a dash of counterculture. An off-grid communications network cobbled together from cheap parts, some of which being strategically hidden within the urban sprawl by rogue operators, certainly sounds like the sort of thing you’d read about it in a William Gibson novel.

But while the DIY nature of Meshtastic is one of its most endearing features for folks like us, it can also be seen as one of its weak spots. Right now, the guidance for those looking to get started is to pick a compatible microcontroller development board, 3D print a case for it, screw on an antenna from AliExpress, flash your creation with the latest firmware, and then spend some quality time with the documentation and configuration tools to actually get it on the air. No great challenge for the average Hackaday reader, but a big ask for the weekend adventurer that’s just looking for a way to keep in touch with their friends while camping.

Quality hardware that offers a turn-key experience will be critical to elevating Meshtastic from a hobbyist’s pastime to something that could actually be fielded for applications such as search and rescue. Plus, let’s be honest, even those of us who like to put together our own gadgets can appreciate a more consumer-oriented piece of hardware from time to time. Especially if that hardware happens to be open source and designed to empower the user rather than hold them back.

Enter the Hacker Pager from exploitee.rs. As the name implies, it’s still very much a device intended for hackers — a piece of hardware designed for the halls of DEF CON rather than trekking through the wilderness. But it’s also an important step towards a new generation of Meshtastic hardware that meets the high standard of quality set by the software itself.

Continue reading “Hands On: The Hacker Pager”

Video Cable Becomes Transmitter With TEMPEST-LoRa

EFI from cables is something every ham loves to hate. What if you modulated, that, though, using an ordinary cable as an antenna? If you used something ubiquitous like a video cable, you might have a very interesting exploit– which is exactly what [Xieyang Sun] and their colleagues have done with TEMPEST-LoRa, a technique to encode LoRa packets into video files.

The concept is pretty simple: a specially-constructed video file contains information to be broadcast via LoRa– the graphics card and the video cable serve as the Tx, and the Rx is any LoRa module. Either VGA or HDMI cables can be used, though the images to create the LoRa signal are obviously going to differ in each case. The only restriction is that the display resolution must be 1080×1920@60Hz, and the video has to play fullscreen. Fullscreen video might make this technique easy to spot if used in an exploit, but on the other hand, the display does not have to be turned on at the time of transmission. If employed by blackhats, one imagines syncing this to power management so the video plays whenever the screen blanks. 

This image sends LoRa. Credit: TEMPEST-LoRa

According to the pre-print, a maximum transmission distance of 81.7m was achieved, and at 21.6 kbps. That’s not blazing fast, sure, but transmission out of a totally air-gapped machine even at dialup speeds is impressive. Code is on the GitHub under an MIT license, though [Xieyang Sun] and the team are white hats, so they point out that it’s provided for academic use. There is a demo video, but as it is on bilbili we don’t have an easy way to embed it. The work has been accepted to the ACM Conference on Computer and Communications Security (2025), so if you’re at the event in Taiwan be sure to check it out. 

We’ve seen similar hacks before, like this one that uses an ethernet cable as an antenna. Getting away from RF, others have used fan noise, or even the once-ubiquitous HDD light. (And here we thought casemakers were just cheaping out when they left those off– no, it’s security!)

Thanks to [Xieyang Sun] for the tip! We’ll be checking the tips line for word from you, just as soon as we finish wrapping ferrites around all our cables.

Cat at the door

2025 Pet Hacks Contest: Cat At The Door

This Pet Hacks Contest entry from [Andrea] opens the door to a great collaboration of sensors to solve a problem. The Cat At The Door project’s name is a bit of a giveaway to its purpose, but this project has something for everyone, from radar to e-ink, LoRa to 3D printing. He wanted a sensor to watch the door his cats frequent and when one of his cats were detected have an alert sent to where he is in the house

There are several ways you can detect a cat, in this project [Andrea] went with mmWave radar, and this is ideal for sensing a cat as it allows the sensor to sit protected inside, it works day or night, and it doesn’t stop working should the cat stand still. In his project log he has a chapter going into what he did to dial in the settings on the LD2410C radar board.

How do you know if you’re detecting your cat, some other cat, a large squirrel, or a small child? It helps if you first give your cats a MAC address, in the form of a BLE tag. Once the radar detects presence of a suspected cat, the ESP32-S3 starts looking over Bluetooth, and if a known tag is found it will identify which cat or cats are outside waiting.

Once the known cat has been identified, it’s time to notify [Andrea] that his cat is waiting for his door opening abilities. To do this he selected an ESP32 board that includes a SX1262 LoRa module for communicating with the portable notification device. This battery powered device has a low power e-paper display showing you which cat, as well as an audio buzzer to help alert you.

To read more details about this project head over to the GitHub page to check out all the details. Including a very impressive 80 page step-by-step guide showing you step by step how to make your own. Also, be sure to check out the other entries into the 2025 Pet Hacks Contest.

Continue reading “2025 Pet Hacks Contest: Cat At The Door”