A Fresh Linux For The Most Unexpected Platform – The Nintendo 64

January 1, 2021 by 24 Comments

Though it was famously started by Linus Torvalds as “a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones“, the Linux kernel and surrounding operating system ecosystems have been ported to numerous architectures beyond their x86 roots. It’s therefore not unusual to hear of new ports for unsupported platforms, but it is extremely unexpected to hear of one when the platform is a games console from the mid-1990s. But that’s what [Lauri Kasanen] has done, announcing a fresh Linux port for the Nintendo 64.

This isn’t a Linux from 1996 either. The port builds on an up-to-date kernel version 5.10 with his N64 branch and a tantalising possibility that it might be incorporated into the main Linux source for the MIPS-64 processor architecture. That’s right, the Nintendo 64 could be an officially supported Linux platform.

It would be stretching the story a long way to call this any kind of distro, for what he’s produced is a bootloader that loads the kernel and creates a terminal with busybox loaded. With this on your flashcart you won’t be replacing that Raspberry Pi any time soon, so why other than [Lauri]’s “because I can” would you be interested in it? He supplies the answer and it lies in the emulation scene, because having a Linux for the platform makes it so much easier to port other software to it. If this tickles your fancy you can see the source in his GitHub repository, and we’re certainly looking forward to what the community will do with it.

We are more used to seeing the N64 as a subject for case-modding, whether it be as a handheld or a an all-in-one console.

Via Phoronix, and thanks [David Beckershoff] for the tip.

Header image: Evan-Amos, Public domain.

DIY Injection Molding Press

January 1, 2021 by 24 Comments

While 3D printing has now become easily accessible and cheap, there are still several use cases where you need the advantages offered by injection molding, even for small batch runs. Professional small-batch injection molding can be pretty expensive, and buying a manual machine can cost quite a bit. Of course, there are a number of DIY injection molding projects to choose from, but they usually involve a fair amount of tools and labour. [Bolzbrain] wanted to bypass all of the heavy cutting, welding and frame assembly work, so he’s built himself a DIY Injection Molding Press for cheap using an off the shelf, six ton hydraulic press. At final count, he ended up spending about €150 for the machine and another €120 for tools to build the machine. He also managed to locate a cheap, local CNC service that gave him a good deal on machining the Dies. But of course you can’t put a price on the lessons learnt and the satisfaction of having built it by hand.

Choosing the hydraulic press is a great idea as it provides the high pressure needed for the job without the operator having to exert a lot of effort, which is a big drawback with some of the other DIY machines. As a bonus, the structural frame is quite sturdy and well suited for this purpose. The other main part of such a machine is the heated injection block and there are several different ways of doing it. After some amount of studying probable solutions, he decided to build a heated aluminium block through which the plastic granules can be rammed using the hydraulic piston. Heating is provided by a pair of 500W heaters and a type ‘k’ thermocouple does temperature sensing. An industrial PID controller adjusts the block temperature via a solid state relay. Overall, the electrical and mechanical layout cannot get any simpler.

[Bolzbrain] did a great job of documenting his build over a series of videos and more wizened hackers watching them will squirm in their seats spotting the numerous fails. He bought the cheapest pedestal drill machine that he could buy and watching the drill struggle while making a 26mm hole in the aluminium block is quite jarring.

The electrical wiring has a lot of scope for improvement – with 220V AC heaters, exposed wiring and jury rigged panel held up with a pair of clamps. Installing and removing the die is a task and requires a lot of fiddling with several C-clamps — something which needs to be repeated for every shot. Maybe toggle clamps could help him to ease die fixing and removal. Once he figures out about mold release agents and wall draft angles, he won’t have to struggle trying to remove the molded article from the die. Then there’s the issue of proper runner design so that the thermo-plastic can quickly fill the mold cavity completely without any pockets.

But in the end, all that matters is that he is getting reasonably good molded parts for his purposes. With more tweaking and incremental improvements, we’re sure he’ll get better results. The video after the break is a short overview of his build, but the project page has a series of detailed videos covering all aspects of the project. And if you’d like to get an introduction to desktop injection molding, check out “Benchtop Injection Molding for the Home Gamer”

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The Internet Of Christmas Tree Watering

January 1, 2021 by 5 Comments

There’s nothing quite like a real Christmas tree, but as anyone who’s had one will know there’s also nothing like the quantity of needles that a real tree can shed when it runs short of water. It’s a problem [RK] has tackled, with a Christmas tree water level monitor that has integration with Adafruit’s cloud service to give a handy phone notification when more watering is required.

The real interest in this project lies in the sensor development path. There are multiple ways of water level sensing from floats and switches through resistive and light scattering techniques, but he’s taken the brave step of using a capacitive approach. Water can be used as a dielectric between two parallel metal plates, and the level of the water varies the capacitance. Sadly the water from your tap is also a pretty good conductor, so the first attempt at a capacitive sensor was not effective. This was remedied with a polythene “sock” for each electrode constructed with the help of a heat sealer. The measurement circuit was simply a capacitive divider fed with a square wave, from which an Adafruit Huzzah board could easily derive an amplitude reading that was proportional to the water level. The board then sends its readings to Adafruit.io, from which a message can be sent to a Slack channel with the notification enabled. All in all a very handy solution.

Plant care is a long-running theme in Hackaday projects, but not all of them need a microcontroller.

Domino Layer Lets You Focus On Toppling

January 1, 2021 by 12 Comments

Knocking dominoes down is a fun pastime for a rainy afternoon, but setting them all up can be a drag. Thankfully, [Lewis] of [DIY Machines] has built a helpful machine to do the job for you, letting you focus on the fun part instead!

The machine is run by an Arduino Uno, that can be pre-programmed with a layout or controlled over Bluetooth in real time. It uses a geared-down DC motor to drive around a smooth surface, with a servo for steering. A second servo is used to turn a carousel loaded with up to 130 dominoes, allowing the machine to lay long runs without needing a refill. It’s designed to be easy to change so multiple carousels can be printed to quickly run courses of extended lengths.

The build is a great example of a machine capable of doing a tricky task with ease, thanks to 3D printing and smart design. We’re particularly impressed with the simple domino transport mechanism integrated into the drive system without requiring extra motors or servos. It’s not the first domino layer we’ve seen, either. Video after the break.

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Number Bases Stretch The Mind

January 1, 2021 by 22 Comments

Some of us might solve crossword puzzles or Sudoko games to exercise our minds, but [Nathan Nichols] plays with exotic number systems to keep the brain cells in shape. He wrote the Hanoi C99 library while in high school, implementing several of his favorites.

We have all been using decimal (base 10) and duodecimal (base 12, as in clocks) since before grade school. Us computer geeks are also adept at various computer-friendly systems like binary, octal, and hexadecimal. The true nerds among us will be familiar with systems like vigesimal (base 20 Mayan numerals) and sexagesimal (base 60 Babylonian numbers). We ourselves espoused the virtues of seximal (base 6) a couple of years ago. But if you really want to stretch your mind, take a dive into the weird number systems that [Nathan] has been exploring.

Negabinary (base -2)

The lowest level of weirdness in the group, this one is almost normal. Its the same as binary, except the bit weights have alternating signs: { 1, -2, 4, -8, ... }.

Binarions (base -1+i)

Or base -1+j if you studied electrical engineering. The use of complex numbers as radices was proposed by Donald Knuth way back in 1955. We find it really hard to imagine this one being helpful.

Fibonacci base

Numbers can also be represented by the summation of a sequence of Fibonacci numbers. Using this system, a number can sometimes be represented more than one way, so watch out.

Stern-Brocot tree

A number is represented by its path down the Stern-Brocot tree. One feature of this system is that numbers can be exact. For example, the Stern-Brocot tree representation of one-third has a finite number of digits.

While [Nathan]’s library only performs conversion at input or output, we wonder if someone will take this further and implement an arithmetic unit inside an FPGA. Besides being a fun exercise, it would baffle someone casually trying to reverse engineer your secret calculations. Let us know of any strange number systems you have used or encountered.

Transforming Drone Can Be A Square Or A Dragon

January 1, 2021 by 8 Comments

When flying drones in and around structures, the size of the drone is generally limited by the openings you want to fit through. Researchers at the University of Tokyo got around this problem by using an articulating structure for the drone frame, allowing the drone to transform from a large square to a narrow, elongated form to fit through smaller gaps.

The drone is called DRAGON, which is somehow an acronym for the tongue twisting description “Dual-Rotor Embedded Multilink Robot with the Ability of Multi-Degree-of-Freedom Aerial Transformation“. The drone consists of four segments, with a 2-DOF actuated joint between each segment. A pair of ducted fan motors are attached to the middle of each segment with a 2-DOF gimbal that allows it to direct thrust in any direction relative to the segment. For normal flight the segments would be arranged in the square shape, with minimal movement between the segments. When a small gap is encountered, as demonstrated in the video after the break, the segments rearrange into a dragon-like shape, that can pass through a gap in any plane.

Each segment has its own power source and controller, and the control software required to make everything work together is rather complex. The full research paper is unfortunately behind a paywall. The small diameter of the propellers, and all the added components would be a severe limiting factor in terms of lifting capacity and flight time, but the concept is to definitely interesting.

The idea of shape shifting robots has been around for a while, and can become even more interesting when the different segment can detach and reattach themselves to become modular robots. The 2016 Hackaday Grand Prize winner DTTO is a perfect example of this, although it did lack the ability to fly. Continue reading “Transforming Drone Can Be A Square Or A Dragon” →

DIY 8-Bit Computer Knows All The Tricks

December 31, 2020 by 12 Comments

Some projects are a rite of passage within their respected fields. For computer science, building one’s own computer from scratch is certainly among those projects. Of course, we’re not talking about buying components online and snapping together a modern x86 machine. We mean building something closer to a fully-programmable 8-bit computer from the ground up, like this one from [Federico] based on 74LS logic chips.

The computer was designed and built from scratch which is impressive enough, but [Federico] completed this project in about a month as well. It can be programmed manually through DIP switches or via a USB connection to another computer, and also includes an adjustable clock which can perform steps anywhere from 1 Hz to 32 kHz. Complete with a 1024 byte memory, a capable ALU, four seven-segment LEDs and (in the second version of the computer) a 2×16 LCD disply, this 8-bit computer has it all.

Not only is this a capable machine designed by someone who clearly knows his way around a logic chip, but [Federico] has also made the code and schematics available on his GitHub page. It’s worth a read even without building your own, but if you want to go that route without printing an enormous PCB you can always follow the breadboard route.

Thanks to [killergeek] for the tip!

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