The Open Source Mars Rover, One Year Later

July 2, 2020 by Tom Nardi 18 Comments

As the name implies, here at Hackaday we strive to bring you interesting projects every single day. But that doesn’t necessarily mean a project only gets one day to grace these storied pages. Quite the opposite, in fact. We’re always happy to revisit a project and find out how far it’s evolved since we last crossed paths with it, especially when the creators themselves reach out to give us an update.

Which is exactly what happened when [Jakob Krantz] recently wrote in to get us up to speed on this incredible open source rover project. We first saw this 3D printed Curiosity inspired robot a little less than a year ago, and at that point it was essentially just a big box with the distinctive NASA rocker-bogie suspension bolted on. Now it not only looks a lot closer to the Martian rovers that inspired it, but it’s also learned a number of new tricks that really take this project to the next level.

The articulated head and grabber arm don’t just help sell the Curiosity look, they’re actually functional. [Jakob] notes that he doesn’t have kinematics integrated yet, so moving the arm around is more for show than practical application, but in the future it should be able to reach out and grab objects. With the new cameras in the head, he’ll even be able to get a first person view of what he’s picking up.

Last year [Jakob] was using a standard RC transmitter to drive the rover around, but he’s since put together a custom controller that’s truly a thing of beauty. It uses an ESP32 and LoRa module to communicate with matching hardware inside the rover, as well as a smartphone clipped onto the top that’s displaying telemetry and video over WiFi. The controller is actually its own separate project, so even if you aren’t in the market for a scaled down Mars rover, its controller could come in handy for your next robotics project.

Presumably the multi-mission radioisotope thermoelectric generator (MMRTG) on the back of the rover is just pretend….but with this guy, we’re not so sure. Give him another year, and who knows.

An Off-The-Grid Instant Messaging Plattform

July 2, 2020 by Moritz v. Sivers 19 Comments

Having an open-source communication device that is independent of any network and works without fees sounds like a hacker’s dream come true. Well, this is exactly what [bobricius]’ is aiming at with his Armawatch and Armachat devices.

Recently, [bobricius] built a LoRa based instant messaging device named Armachat. The gadget is controlled by a SAMD21 MCU with native USB and includes a QWERTY keyboard and an LCD display. Communication is based on an RFM95 LoRa transceiver which can reach a range of up to 2 km under ideal conditions. [bobricius] is a wiz when it comes to PCB design and one thing that makes his projects look so good is how he often uses PCBs as enclosures.

Armachat came in two form factors a large desktop and a smaller pocket version. The new Armawatch is another downsized version that perfectly fits on your arm by using a smaller display and keyboard. [bobricius] also did a lot of work on the firmware which now features a message delivery confirmation and the possibility to automatically resend undelivered messages. Future improvements will include message encryption, a store-and-forward function, and GPS position parsing. [bobricius] is also working on completing his portfolio of communicators with a credit-card-sized version.

LoRa is the go-to technology for off-the-grid communication devices and there are already other ongoing projects for using it to construct a mesh network.

Capture The Flag, Along With The Game Data

June 18, 2020 by Kristina Panos 7 Comments

With events of all sizes on hold and live sports mostly up in the air, it’s a great time to think of new ways to entertain ourselves within our local circles. Bonus points if the activity involves running around outside, and/or secretly doubles as a team-building exercise, like [KarelBousson]’s modernized version of Capture the Flag.

Much like the original, the point of this game is to capture the case and keep it for as long as possible before the other team steals it away. Here, the approach is much more scientific: the box knows exactly who has it and for how long, and the teams get points based on the time the case spends in any player’s possession.

Each player carries an RFID tag to distinguish them from each other. Inside the case is an Arduino Mega with a LoRa shield and a GPS unit. Whenever the game is afoot, the case communicates its position to an external Raspi running the game server.

If you haven’t met LoRa yet, check out this seven-part introductory tutorial.

Custom Firmware Makes A LoRA-Enabled HAB Tracker Watch

May 6, 2020 by Donald Papp 4 Comments

High Altitude Balloons (HAB) are a great way to get all kinds of data and shoot great photos and video, but what goes up must come down. Once the equipment has landed, one must track it down. GPS and LoRA, with its long wireless range and ease of use, are invaluable tools in tracking payloads that have returned to Earth. [Dave Akerman] has made handheld receivers to guide him to payloads, but wanted something even smaller; ideally something that could be worn on the wrist.

One day he came across the affordable LilyGo T-Watch which includes GPS and LoRA functionality, and he started getting ideas. The watch has the features, but the stock firmware didn’t measure up. Not to be deterred, [Dave] wrote new firmware to turn the device into a wrist-worn GPS and LoRA chase watch.

Not only is the new firmware functional, but it’s got a wonderful user interface. GitHub repository for the new firmware is here, and you can see the UI in action in the brief video embedded below.

Continue reading “Custom Firmware Makes A LoRA-Enabled HAB Tracker Watch” →

A LoRa IM-Me For The End Of The World

April 25, 2020 by Jenny List 25 Comments

Enshrined in the hacker hall of fame, the IM-Me was an instant messaging toy that turned out to be extremely hackable. You could easily ditch its instant messaging platform to turn it into a little spectrum analyser. Of course what’s old is new again, and in this age where we no longer have the Nokia 3110, the Sidekick, or even Blackberries, how shall we get our fix of those wireless gadgets with physical keyboards?

What would happen if a hacker had a go at creating one of those? [Bobricius]’ Armachat is an instant messaging platform that uses LoRa as its over-the-air protocol, and is powered by a Microchip ATSAMD21x18 ARM Cortex M0 microcontroller alongside an RFM95 LoRa module.

The IM-Me, a free text chat device in the age of per-message charges, was the sweat heart of hardware hacking back in 2010

There are two versions of the device for hand and pocket, both of which come with QWERTY keyboards made with momentary-action switches, 18650 cell power, and LCD screens. The idea is that it could form a robust communication system when many others have failed.

As it stands they have a simple text messaging app in the firmware, but there are other features yet to come. Perhaps the most interesting is a possible store-and-forward meshing system in the future, which would make this a powerful comms tool in so many circumstances. Both of [Bobricius’] devices can be seen in the video below the break — no word from him on the possibility of a pink case option. Meanwhile [Bobricius] has appeared on these pages many times before. With so many to choose from it’s hard to pick one, but his Nixie-like LED display is quite memorable.

Continue reading “A LoRa IM-Me For The End Of The World” →

High Power LoRa And Tropospheric Reflection Experiments

March 21, 2020 by Jenny List 29 Comments

We’re used to LoRa as a free-to-use digital radio protocol allowing not-very-high data rate communications over distances of a few miles. It’s made all kinds of distributed sensor systems a breeze, and some experimenters have made an art of achieving communication over hundreds of miles. But what would happen if you took a brute-force approach to LoRa and simply wound up the power?

In a bid to test its efficiency at bouncing off the troposphere in normal conditions, [Inductive Twig] hooked up a HamShield 70cm LoRa shield to an 80W power amplifier and a high-gain Yagi antenna pointing directly upwards mounted with ingenuity on a spade, and drove around looking at the received result. With an effective radiated power of 1500W this wasn’t your normal LoRa, instead being operated with LoRa as an amateur radio mode.

For those not familiar with radio propagation, radio waves bounce off some surprising things. In this case the aim was to bounce them off the troposphere, but while radio amateurs and LoRa distance chasers wait until weather conditions deliver a so-called “lift” in which the troposphere is especially reflective, here the experiment was performed under normal flat conditions. The result characterizes LoRa’s possibilities for everyday extreme-range mode rather than chasing records, and in that there were some interesting results. The reflected signal was receivable in bursts with low but consistent signal strength, with the limiting factor during the test as that they ran out of land upon which to drive in the southernmost peninsula of New Jersey. We’ve heard of War-Driving for open WiFi… does this car dashboard setup count as LoRa-Driving?

LoRa is designed as a protocol tolerant of low signal levels and some packet loss, so this experiment is an interesting demonstration of its possibilities when used at higher powers under a licensed transmission. It shouldn’t be possible to use the 70cm band for reliable tropospheric propagation under non-lift conditions, but this shows that it can be done. Meanwhile, take a look at a previous attempt to push LoRa using a balloon.

LoRa Mesh Network With Off-the-Shelf Hardware

February 26, 2020 by Tom Nardi 29 Comments

An ideal application for mesh networking is off-grid communication; when there’s no cellular reception and WiFi won’t reach, wide-area technologies like LoRa can be used to create ad hoc wireless networks. Whether you’re enjoying the outdoors with friends or conducting a rescue operation, a cheap and small gadget that will allow you to create such a network and communicate over it would be a very welcome addition to your pack.

That’s exactly the goal of the Meshtastic project, which aims to take off-the-shelf ESP32 LoRa development boards and turn them into affordable mesh network communicators. All you need to do is buy one of the supported boards, install the firmware, and starting meshing. An Android application that will allow you to use the mesh network to send basic text messages is now available as an alpha release, and eventually you’ll be able to run Signal over the LoRa link.

Navigating to another node in the network.

Developer [Kevin Hester] tells us that these are still the very early days, and there’s plenty of work yet to be done. In fact, he’s actively looking to bring a few like-minded individuals onto the project. So if you have experience with the ESP32 or mobile application development, and conducting private communications over long-range wireless networks sounds like your kind of party, this might be your lucky day.

From a user’s perspective, this project is extremely approachable. You don’t need to put any custom hardware together, outside of perhaps 3D printing a case for your particular board. The first time around you’ll need to flash the firmware with esptool.py, but after that, [Kevin] says future updates can be handled by the smartphone application.

Incidentally, the primary difference between the two boards is that the larger and more expensive one includes GPS. The mesh networking side of things will work with either board, but if everyone in your group has the GPS-equipped version, each user will be able to see the position of everyone else in the network.

This isn’t the first time we’ve seen LoRa used to establish off-grid communications, and it surely won’t be the last. The technology is perfect for getting devices talking where there isn’t any existing infrastructure, and we’re excited to see more examples of how it can be used in this capacity.