RC Lawnmower Is Built To Last

August 2, 2022 by 17 Comments

Mowing the lawn is one of those tasks that someone will always be optimizing or automating. To allow him to mow the lawn while seated comfortably in the shade, [Workshop from Scratch] built an RC Lawnmower in his signature solid steel frame style.

The chassis consists of a heavy welded steel frame from square tubing, with a pair of knobbly go-kart wheels on the back and large caster wheels on the front. The actual grass-cutting part is a 173cc petrol lawnmower engine with a steel hull, mounted on an articulating subframe which can be remotely raised and lowered using a linear actuator. The rear wheels are attached to a pair of custom sprocket hubs, driven via chain by two 200 W geared DC motors to allow skid steering.

The motors and electronics are powered by a set of 18 Ah lead-acid batteries wired in parallel. The petrol engine can also charge the batteries, but its current isn’t enough to keep up while mowing. However, it does help to extend the range. All the electronics are housed in a plastic enclosure with a power switch, key start for the engine, and battery charge indicator on the lid. The power from the batteries runs through a pair of automotive relays connected to the power switch and a set of fuses for protection. For safety [Workshop from Scratch] wired a relay to the engines’ coil to shut it off remotely, or when the radio link to the controller is lost. An action cam was also mounted on the electronics box to stream a first-person view to a smartphone over WiFi.

Overall this is a very well built project, especially mechanically, and looks like the perfect platform for further self-driving using Ardurover. [rctestflight] has demonstrated the capabilities of the open source autopilot with several rovers, including a tiny lawnmower that cuts grass with Exacto blades.

Continue reading “RC Lawnmower Is Built To Last” →

The Rollercoaster Of Developing The Ultimate Hackable Keyboard

August 2, 2022 by 14 Comments

When designing anything with “hackable” in the punchline, scope creep is an integral part of the process. You end up trying to create something to potentially be an infinite number of things for an infinite number of users. [Zack Freedman] is going really deep down the rabbit hole with his MiRage keyboard and has been documenting the progress in his usual entertaining style, with some cautionary notes included.

The most fascinating tale from this come about as a result of adding RGB LEDs beneath the keys, while still allowing everything to function when the keyboard is split in two. Thanks to an IO expander chip in one side of the board, a standard TRRS audio cable is enough to link both sides together. But the addition of addressable LEDs meant more lines were required.

[Zack] thought he had found a solution in the form of SATA cables, but it turns out all SATA cables internally connect pins 1,3, and 7, making them useless for this application. He realized he had no choice but to add a second microcontroller to the “dumb” side of the keyboard and return to I2C over a TRRS cable. However, the RP2040-based Seeed XIAO’s I2C absolutely refused to play along. After a fortnight of frustrating debugging, it turns out there was a bug in the pin definitions. Fortunately, this also revealed that the XIAO had an undocumented secondary I2C interface, which he plans to configure as a peripheral to make the keyboard almost infinitely expandable with additional keys.

An earlier version of the MiRage featured tactile OLED displays, but it turns out the thin panes of glass don’t handle repeated flexing well, so they had to be scrapped. In their place came a touchscreen E-paper display, but now this seems to be evolving into a pluggable module for any input device that your heart desires, including possibly a haptic SmartKnob. Another major update are PCB footprints that support both CHOC and MX switches.

It all started with the MiRage V1 keyboard intended to for use in an updated version of [Zack]’s cyberdeck. After realizing how many people were interested in the keyboard but not the cyberdeck, he shifted focus to refining the MiRage.

This project still has some way to go, so we’ll certainly be keeping our eye on it. In the meantime, we’ve recently covered another exceptionally customizable keyboard that might catch your fancy.

Continue reading “The Rollercoaster Of Developing The Ultimate Hackable Keyboard” →

Toyota’s Cartridge Helps Make Hydrogen Portable

August 2, 2022 by 139 Comments

Hydrogen has long been touted as the solution to cleaning up road transport. When used in fuel cells, the only emissions from its use are water, and it eliminates the slow recharging problem of battery-electric vehicles. It’s also been put forth as a replacement for everything from natural gas supplies to laptop batteries.

Toyota has been pushing hard for hydrogen technology, and has worked to develop vehicles and infrastructure to this end. The company’s latest efforts involve a toteable hydrogen cartridge – letting you take hydrogen power on the go!

Continue reading “Toyota’s Cartridge Helps Make Hydrogen Portable” →

Homemade SawStop Attachment Is Just About As Sketchy As It Sounds

August 2, 2022 by 56 Comments

TL;DR — when [Colin Furze] is your “safety inspector,” you really should be reconsidering your project goals.

Most of us have probably by now seen the SawStop brand of self-stopping table saw, which detects when something meatier than wood has the bad taste to touch the spinning blade, more or less instantly stopping it and preventing sudden traumatic amputations. It’s an outstanding idea, and we’d love to see the technology built into all table saws. But alas, SawStop saws are priced out of reach for many woodworkers, which left [Ruth Amos] to roll her own DIY version of the system.

It should be stated right off the bat that none of what [Ruth] does here is a good idea, and that everything shown is really just a proof of concept. The basis for her build was a somewhat flimsy-looking contractor-style saw, to which [Ruth] attached an Arduino set up to detect when something conductive touches the blade. She shares no particulars on the sensing method, but our guess is capacitive coupling. She then sets about experimenting with a series of above-table gizmos to arrest the blade, with limited success, plus all the attachments would make the saw essentially useless. But working above the table does make sense in the prototyping phase, and allowed her to figure out what wouldn’t work.

In the end, it was an electromagnetic clutch from an electric lawnmower that seemed to do the trick, albeit at the expense of heavy mods to the saw and a considerable increase in the system’s angular momentum. Nonetheless, the blade stops pretty close to instantly in the old hot dog test. It doesn’t drop the blade below the table, of course, and the hot dog is a little worse for the wear, but it’s still pretty impressive.

We’ve discussed SawStop’s technology before and why it isn’t perhaps as widely available as it should be, if you’re curious.

Continue reading “Homemade SawStop Attachment Is Just About As Sketchy As It Sounds” →

An illuminated MCH2022 sign composed of large LED letters

Mutually Crafted Happiness: How MCH2022 Happened

August 2, 2022 by 16 Comments

Just a few days ago, MCH2022, a six day long hacker camp in Netherlands, has concluded – bringing about three thousand hackers together to hang out. It was my first trip to a large hacker camp like this, as I’ve only been to smaller ones, and this story is coming from someone who’s only now encountering the complexity and intricacy of one. This is the story of how it’s run on the inside.

MCH2022 is the successor of a hacker camp series in the Netherlands – you might’ve heard of the the previous one, SHA, organized in 2017. The “MCH” part officially stands for May Contain Hackers – and those, it absolutely did contain. An event for hackers of all kinds to rest, meet each other, and hang out – long overdue, and in fact, delayed for a year due to the everpresent pandemic. This wasn’t a conference-like event where you’d expect a schedule, catering and entertainment – a lot of what made MCH cool was each hacker’s unique input.

Just like many other camps similar to this, it was a volunteer-organized event – there’s no company standing behind it, save for a few sponsors with no influence on decisionmaking; it’s an event by hackers, for hackers. The Netherlands has a healthy culture of hackerspaces, with plenty of cooperation between them, and forming a self-organized network of volunteers, that cooperation works magic. Continue reading “Mutually Crafted Happiness: How MCH2022 Happened” →

The GameTank Is The Latest And Greatest 8-bit Game Console

August 2, 2022 by 15 Comments

The NES, Atari 2600, the Apple II, the Commodore 64 and the TurboGrafx-16 are just some of the many game consoles and home computers built around the 6502 CPU. And while the 6502 has been pretty much obsolete since the mid-’90s, that hasn’t stopped hackers from building new systems with it in the 21st century. Today we can even show you an entirely new 6502-based game console: the GameTank, designed and built by [Clyde Shaffer].

The GameTank was designed to be easy to build by anyone, and is therefore largely constructed from DIP chips that can be bought new at any component distributor. The main CPU is a WD65C02 running at 3.5 MHz, assisted by a 6522 I/O controller and 32 kB of RAM. Composite video is generated by a clever circuit made out of discrete logic chips. The video card comes with DMA for fast transfers and even includes a blitter, which enables it to move images around the screen quickly without loading the CPU.

For the controllers, [Clyde] decided to go for the more-or-less industry standard DE-9 connector gamepads as used on the Sega Genesis and various Atari consoles. He also made his own controller, a 3D printed one with four directional buttons, three action buttons and a start button. The buttons are implemented with Cherry MX Clear switches — an unusual choice for a gamepad perhaps, but they’re apparently very comfortable for long gaming sessions.

The console itself is also housed in a printed enclosure with a design reminiscent of the Nintendo 64. Game cartridges are inserted at the top and contain an EEPROM chip that can be written with a special programmer. The cartridge port also brings out several internal signals and can therefore be used as an expansion port, similar to the way Super NES cartridges could accommodate enhancement chips.

Games currently available include Tetris, the office-themed platformer Cubicle Knight, a Zelda-style adventure named Accursed Fiend, and a remake of the classic viral animation Bad Apple. [Clyde] provides a comprehensive stack of tools and example code and invites anyone interested to help develop more software for the platform. There’s also a hardware-accurate emulator, which is not only useful if you’re writing new code for the system but also if you simply want to try out the existing games in your browser.

Rolling your own 6502 system is great fun, and we’ve seen several examples over the years: some are built with huge bundles of wire, some are come with a clever programming language, some are so tiny they fit on your wrist, and some are simply beautifully made.

Continue reading “The GameTank Is The Latest And Greatest 8-bit Game Console” →

Hoverboard Powered Sofa Is Fun And A Bit Dangerous

August 2, 2022 by 8 Comments

Discarded hoverboards are a great source of free high torque motors for hacking. This can include crazy but fun projects like this hoverboard-driven IKEA sofa, as demonstrated by [Bitluni] and his friends at xHain Hackerspace in Berlin.

With a couple of dead hoverboards in various conditions and a working e-bike battery, the group started exploring different options to put together a usable drivetrain. The first attempt involved commanding the motor drivers directly by intercepting communication from the gyro-based controller. The 9-bit communication protocol was a tough nut to crack, so they tried (and failed) to use the gyro-boards directly as the controllers. In the process of researching they discovered someone had created alternative firmware for the hoverboard controllers to allow control with a Wii Nunchuck. There is even a web-based config tool for compiling the firmware.

With some wood spacers screwed to the bottom of the sofa, the hoverboard motors could be attached by simply screwing their enclosure to the bottom of the couch and adding a section of PVC pipe between the halves for wiring. Caster wheels were added to the rear corners of the sofa to complete the chassis. The motors were very sensitive to control inputs on the Nunchuck, so riding the couch tended to rapidly turn into a rodeo event. The couch also wasn’t made to carry its load on the outer corners, so it had to be reinforced with plywood after it started cracking.

We’ve seen plenty of hacks that involve hoverboard motors, including an electric skateboard with mecanum wheels and a surprisingly practical e-bike conversion.

Continue reading “Hoverboard Powered Sofa Is Fun And A Bit Dangerous” →