Open-Source Farming Robot Now Includes Simulations

March 17, 2022 by Bryan Cockfield 14 Comments

Farming is a challenge under even the best of circumstances. Almost all conventional farmers use some combination of tillers, combines, seeders and plows to help get the difficult job done, but for those like [Taylor] who do not farm large industrial monocultures, more specialized tools are needed. While we’ve featured the Acorn open source farming robot before, it’s back now with new and improved features and a simulation mode to help rapidly improve the platform’s software.

The first of the two new physical features includes a fail-safe braking system. Since the robot uses electric geared hub motors for propulsion, the braking system consists of two normally closed relays which short the motor leads in emergency situations. This makes the motors see an extremely high load and stops them from turning. The robot also has been given advanced navigation facilities so that it can follow custom complex routes. And finally, [Taylor] created a simulation mode so that the robot’s entire software stack can be run in Docker and tested inside a simulation without using the actual robot.

For farmers who are looking to buck unsustainable modern agricultural practices while maintaining profitable farms, a platform like Acorn could be invaluable. With the ability to survey, seed, harvest, and even weed, it could perform every task of larger agricultural machinery. Of course, if you want to learn more about it, you can check out our earlier feature on this futuristic farming machine.

A PNG Based Circuit Simulator

February 16, 2022 by Matthew Carlson 12 Comments

We’re sure thousands of hours have been spent in Minecraft implementing digital logic. Inspired by that, [lynnpepin] created a digital logic simulator named Reso that is based on pixels rather than voxels.

There are a few clever things here. First, different colors represent different parts. There are three different colors of wire, output and input wires, XOR gates, and AND gates. OR gates are just output wires, which or all the input wires together. By implementing these gates, Reso is, by definition, Turing complete. Since it’s just a PNG, it is trivial to open it up in GIMP and copy and paste one bit of the circuit multiple times. The different color wires are mainly to help route in a 2d plane, as you don’t have vias. Currently, the image compiles into a graph that is executed. [Lynn] chose code readability and ease of prototyping over premature optimization, so the code isn’t particularly fast. But it is pretty fun, squinting at the pixels that make up the adders and clocks he has on his blog. After giving Reso your image, it outputs a series of images that enumerate the state for several states.

The code is available on Github, and a Rust version has already been written that offers some impressive speed improvements at the expense of not being at feature parity yet. If MS-Paint isn’t your IDE of choice, perhaps a more Javascript-based digital logic simulator might be more to your taste.

Remoticon 2021: Uri Shaked Reverses The ESP32 WiFi

December 30, 2021 by Elliot Williams 9 Comments

You know how when you’re working on a project, other side quests pop up left and right? You can choose to handle them briefly and summarily, or you can dive into them as projects in their own right. Well, Uri Shaked is the author of Wokwi, an online Arduino simulator that allows you to test our your code on emulated hardware. (It’s very, very cool.) Back in the day, Arduino meant AVR, and he put in some awesome effort on reverse engineering that chip in order to emulate it successfully. But then “Arduino” means so much more than just AVR these days, so Uri had to tackle the STM32 ARM chips and even the recent RP2040.

Arduino runs on the ESP32, too, so Uri put on his reverse engineering hat (literally) and took aim at that chip as well. But the ESP32 is a ton more complicated than any of these other microcontrollers, being based not only on the slightly niche Xtensa chip, but also having onboard WiFi and its associated binary firmware. Reverse engineering the ESP32’s WiFi is the side-quest that Uri embarks on, totally crushes, and documents for us in this standout Remoticon 2021 talk. Continue reading “Remoticon 2021: Uri Shaked Reverses The ESP32 WiFi” →

Mechanical Linkage CAD For Everyone

October 21, 2021 by Al Williams 32 Comments

As much as some of us don’t like it, building things for real requires some mechanical component. Maybe it is something as simple as an enclosure or even feet for a PCB, but unless you only write software or play with simulators, you’ll eventually have to build something. It is a slippery slope between drilling holes for a front panel and attempting to build things that move. Sometimes that’s as simple as a hinge and a spring, or maybe it is a full-blown robot articulated arm. That’s why [RectorSquid] built Linkage, a “program that lets you design and edit a two-dimensional mechanism and then simulate the movement of that mechanism” (that quote is from the documentation.

The program has had a few versions and is currently up past 3.15. To get an idea of the program’s capabilities, the first video below shows an older version simulating a ball lift. The second video shows the actual mechanism built from the design. The associated YouTube channel has more recent videos, too, showing a variety of simulations.

Continue reading “Mechanical Linkage CAD For Everyone” →

ZeroBug: From Simulation To Smooth Walking

July 21, 2021 by Danie Conradie 9 Comments

Thanks to 3D printing and cheap hobby servos, building you’re own small walking robot is not particularly difficult, but getting them to walk smoothly can be an entirely different story. Knowing this from experience, [Max.K] tackled the software side first by creating a virtual simulation of his ZeroBug hexapod, before building it.

Learning from his previous experience building a quadruped, ZeroBug started life in Processing as a simple stick figure, which gradually increased in complexity as [Max.K] figured out how to make it walk properly. He first developed the required movement sequence for the tip of each leg, and then added joints and calculated the actuator movements using reverse kinematics. Using the results of the simulations, he designed the mechanics and pulled it back into the simulation for final validation.

Each leg uses three micro servos which are controlled by an STM32F103 on a custom PCB, which handles all the motion calculations. It receives commands over UART from a python script running on a Raspberry Pi Zero. This allows for user control over a web interface using WiFi, or from a gamepad using a Bluetooth connection. [Max.K] also added a pincer to the front to allow it to interact with its environment. Video after the break.

The final product moves a lot smoother than most other servo-driven hexapods we’ve seen, and the entire project is well documented. The electronics and software are available on GitHub and the mechanics on Thingiverse.

Continue reading “ZeroBug: From Simulation To Smooth Walking” →

A Look Back On A Decade Of Kerbal Space Program

July 19, 2021 by Tom Nardi 24 Comments

Just a few weeks before Atlantis embarked on the final flight of the Space Shuttle program in 2011, a small Mexican company by the name of Squad quietly released Kerbal Space Program (KSP) onto an unsuspecting world. Until that point the company had only developed websites and multi-media installations. Kerbal wasn’t even an official company initiative, it started as a side project by one of their employees, Felipe Falanghe. The sandbox game allowed players to cobble together rockets from an inventory of modular components and attempt to put them into orbit around the planet Kerbin. It was immediately addictive.

There was no story to follow, or enemies to battle. The closest thing to a score counter was the altimeter that showed how far your craft was above the planet’s surface, and the only way to “win” was to put its little green occupant, the titular Kerbal, back on the ground in one piece. The game’s challenge came not from puzzles or scripted events, but from the game’s accurate (if slightly simplified) application of orbital mechanics and Newtonian dynamics. Building a rocket and getting it into orbit in KSP isn’t difficult because the developers baked some arbitrary limitations into their virtual world; the game is hard for the same reasons putting a rocket into orbit around the Earth is hard.

Over the years official updates added new components for players to build with and planets to explore, and an incredible array of community developed add-ons and modifications expanded the scope of the game even further. KSP would go on to be played by millions, and seeing a valuable opportunity to connect with future engineers, both NASA and the ESA helped develop expansions for the game that allowed players to recreate their real-world vehicles and missions.

But now after a decade of continuous development, with ports to multiple operating systems and game consoles, Squad is bringing this chapter of the KSP adventure to a close. To celebrate the game’s 10th anniversary on June 24th, they released “On Final Approach”, the game’s last official update. Attention will now be focused on the game’s ambitious sequel, which will expand the basic formula with the addition of interstellar travel and planetary colonies, currently slated for release in 2022.

Of course, this isn’t the end. Millions of “classic” KSP players will still be slinging their Kerbals into Hohmann transfer orbits for years to come, and the talented community of mod developers will undoubtedly help keep the game fresh with unofficial updates. But the end of official support is a major turning point, and it seems a perfect time to reminisce on the impact this revolutionary game has had on the engineering and space communities.

Continue reading “A Look Back On A Decade Of Kerbal Space Program“ →

Emulating A Power Grid

June 26, 2021 by Bryan Cockfield 23 Comments

The electric power grid, as it exists today, was designed about a century ago to accommodate large, dispersed power plants owned and controlled by the utilities themselves. At the time this seemed like a great idea, but as technology and society have progressed the power grid remains stubbornly rooted in this past. Efforts to modify it to accommodate solar and wind farms, electric cars, and other modern technology need to take great effort to work with the ancient grid setup, often requiring intricate modeling like this visual power grid emulator.

The model is known as LEGOS, the Lite Emulator of Grid Operations, and comes from researchers at RWTH Aachen University. Its goal is to simulate a modern power grid with various generation sources and loads such as homes, offices, or hospitals. It uses a DC circuit to simulate power flow, which is visualized with LEDs. The entire model is modular, so components can be added or subtracted easily to quickly show how the power flow changes as a result of modifications to the grid. There is also a robust automation layer to the entire project, allowing real-time data acquisition of the model to be gathered and analyzed using an open source cloud service called FIWARE.

In order to modernize the grid, simulations like these are needed to make sure there are no knock-on effects of adding or changing such a complex system in ways it was never intended to be changed. Researchers in Europe like the ones developing LEGOS are ahead of the curve, as smart grid technology continues to filter in to all areas of the modern electrical infrastructure. It could also find uses for modeling power grids in areas where changes to the grid can happen rapidly as a result of natural disasters.