Aluminium-Sulphur Batteries For Local Grid Storage?

September 5, 2022 by Dave Rowntree 45 Comments

Lithium-Sulphur batteries have been on the cusp of commercial availability for a little while now, but nothing much has hit the shelves as of yet. There are still issues with lifetime due to cell degradation, and news about developments seems to be drying up a little. Not to worry, because MIT have come along with a new battery technology using some of the most available and cheap materials found on this planet of ours. The Aluminium-Sulphur battery developed has very promising characteristics for use with static and automotive applications, specifically its scalability and its incredible charge/discharge performance.

The cell is based upon electrodes constructed from aluminium metal and sulphur, with a electrolyte of molten catenated chloro-aluminate salts. With an operating temperature of around 100 degrees Celsius, you’re not going to want this in a mobile phone anytime soon, but that’s not the goal. The goal is the smoothing out of renewable energy sources, and localised electricity grid balancing. A major use case would be the mass charging of battery electric vehicles. As the number of charge points increases at any given location, so does the peak current needed from the grid. Aluminium-Sulphur batteries are touted to offer the solution to ease this, with their high peak discharge current capability enabling a much higher peak power delivery at the point of use.
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KittyOS: Writing A Toy OS For The ATmega168 From Scratch

September 5, 2022 by Dave Rowntree 6 Comments

Writing an operating system for a computing platform is one of those non-trivial tasks few people actually need to do, regardless of whether it’s for a small microcontroller or a larger general-purpose computer. Many of us spend a large amount of our time working on producing robust code for embedded systems, occasionally diving deeper into the abstraction when we’re stuck on a problem. Quite often this work is sitting on top of an RTOS, which we consider a solved problem. [Jonathan Diamond] had picked up a fair bit of knowledge of some of the low-level AVR black magic, as well as some details of how operating systems work internally, and so decided to have a crack a building a toy operating system called KittyOS, for the learning experience alone.

[Jonathan] hastens to add that this is not a practical OS, but a learning platform that needs a few more bells and whistles added to be useful. Aimed at the 8-bit AVR ATmega168 with its mere 16kB of flash and 1kB of SRAM, the diminutive chip can still perform more than well enough to host the rudimentary OS — up to four application tasks, and some basic system call support.

Already, KittyOS sports preemptive multitasking, with prioritization and support for applications written in C. Hardware support is a bit limited, with just serial I/O and a spot of GPIO, but that’s more than enough for a demonstrator. Applications can be loaded into any of the four available slots, with per-slot run state control, using the Python-based host interface. The post is a long one, with an absolute ton of the gory details we love around these parts, and we’re very glad [Jonathan] took the time to make a proper write-up as well as a demonstration video, which can be found after the break.

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GP2040: A Configurable Game Pad Firmware

September 4, 2022 by Dave Rowntree 12 Comments

[feralAI] and fellow GitHub contributors present for your viewing pleasure GP2040: an open source game pad firmware for RP2040-based hardware. The dual-core RP2040 is a good platform to use for gaming inputs, as there is plenty of CPU grunt to get sub-1 ms USB polling time, regardless of any other tasks the controller may be performing. Currently the firmware supports PC, Android, RPi, Nintendo Switch, PS3, PS4 (legacy mode), and the sweet MiSTer FPGA-based retro-gaming platform.

The firmware supports the older DirectInput API and the newer shiny (but rather restrictive) XInput API (no, it’s not the old X11 input extension with the same name) — as well as the usual controller features like SOCD cleaning, D-pad mapping, and RGB support for additional distractions. There is even support for those tiny OLED displays (SSD1306 and friends), although we can’t think of a use case for that at the moment. Configuration is particularly interesting, however, as it is based upon an embedded web application. This is where the pin mappings to your actual hardware are defined, as well as all that RGB bling, if you so desire.

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This Pico-W IoT Starter Project Gets You Into Home Assistant Quick As A Flash

September 3, 2022 by Dave Rowntree 20 Comments

Many of us hacker types with some hardware knowledge and a smattering of embedded experience would like to get into home automation, but there can be quite a learning curve. If you’re looking for a hackable starting point; something to deploy, learn about and then later expand upon, then look no further than the PicoW Home Assistant Starter project from [Danilo Campos].

The project is based upon the arduino-pico core, which supports a whole pile of RP2040-based boards, so you don’t need to restrict yourself to the “official” Pico-W, so long as you have working networking, Wi-Fi or otherwise. Integration is provided by the arduino-home-assistant library, which acts as the bridge between your sensors and other widgets, MQTT, and thence the network beyond. Events and sensor data on the end-point are packaged up with MQTT and published out to the broker via the network provided, all for minimal initial effort. Once you’ve got the basic connectivity to your Home Assistant instance working, there are many code examples in the arduino-home-assistant GitHub page to give you a helping start to connect whatever tickles your fancy.

It turns out we’ve covered HA quite a bit on these fair pages, like for example, these sweet automated window blinds. Another hack uses load cells under the bed legs to detect if someone is in bed or not, and if this isn’t your thing, maybe your idea of a home assistant is a bit more like this one?

Cutting The Grass With Frickin’ Lasers

September 2, 2022 by Dave Rowntree 29 Comments

We techie types are quite often much more comfortable in front of a keyboard knocking out code, than out in the yard splitting logs for winter, and even the little jobs like cutting the grass are sometimes just too much like hard manual labour for our liking. The obvious solution is a robot mower, but they’re kinda boring, with their low-tech spinning metal blades. What we need is a big frickin’ laser. YouTuber [rctestflight] has been experimenting with using a 40W blue diode laser module to cut the weeds, (Video, embedded below) and it sort of works, albeit in a rather dangerous fashion.

The first test used a fixed assembly, mounting the laser to a camera lens, upon a rotating gear driven by a small stepper motor. An Arduino controls the beam scanning, very slowly, burning the grass in its sights. But with a range limited to around eight feet best case, sitting in one spot just isn’t going to cut it. (sorry) The obvious next step was to mount one of the tested laser modules onto a moveable platform. After tweaking one of his earlier projects — a tracked rover — with a new gearbox design, it could now drive slow enough to be useful for this slow task. The laser was mounted to a simple linear rail slider, with an attempt at a vacuum pickup system to suck up the clippings, removing them from the beam path, and stopping them impeding the cutting efficiency of the laser.

Obviously this vacuum idea didn’t work, and since the contraption takes the best part of a week to cut just one small area, we reckon it would likely be growing faster than that! Still, it must have been fun to build it anyway. It just goes to show that despite the march of technological progress, maybe the boring old spinning blades of old are still the best way to get the job done.

Lawnmowing is clearly one of those jobs we love to hate, and do so with hacks. Here’s a way to prevent your mower sucking up foreign bodies and hurling them at you at ballistic speeds, and for those who really want to be hands off, add RTK-GPS to a robot mower, and just leave it to do the dirty work.

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Finished pipe crimper made from recycled parts

Making A Pipe Crimper From Scrap

August 30, 2022 by Dave Rowntree 19 Comments

We love upcycling around these parts — taking what would be a pile of rusty scrap and turning it into something useful — and this project from YouTuber [Hands on Table] is no different. Starting with a pair of solid looking sprockets, one big, one small, and some matching chain, a few lumps of roughly hewn steel plate were machined to form some additional parts. A concentric (rear mounted) plate was temporarily welded to the sprocket so matching radial slots could be milled, before it was removed. Next, the sprocket was machined on the inside to add a smooth edge for the crimping fingers (is that the correct term? We’re going with it!) to engage with.

These fingers started life as an off the shelf 3/8″ HSS tool bit, ground down by hand, to produce the desired crimping profile. A small piece of steel was welded on to each, to allow a small spring to act on the finger, enabling it to retract at the end of the crimping action. We did spot the steel plate being held in place with a small magnet, prior to welding. The heat from that would likely kill off the magnetic field in a short space of time, but they’re so cheap as to be disposable items anyway.

A small ring rides on top of the assembly, bolted to the fixed rear plate. The prevents the crimping fingers from falling out . The fingers are constrained by the slots in the rear plate, so the result is that they can only move radially. As the big sprocket is rotated, they get progressively pushed towards the center, giving that nice, even crimping action. Extra mechanical advantage is provided by driving the small sprocket with a wrench. Super simple stuff, and by the looks of the device in action, pretty effective at crimping the hose fittings it was intended for.

Taking one thing and turning it into something else may well be the very essence of hacking. We’ve seen many hacky upcycling efforts, such as this bench disk sander built from a dryer machine motor. Of course, upcycling is not limited to machines, tools and electronic doodads. Here a trapper hat made out of an old skirt. And why not?

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A Beautiful DIY Guided Saw

August 30, 2022 by Dave Rowntree 19 Comments

[JSK-koubou] has quite the talent for creative woodwork, particularly building interesting tools or improving existing ones. This recent project (multiple build videos below: part 1, part 2, and part 3) is a very flexible type of guided pull saw, whereby a fine-toothed saw blade is fixed in the bed, and the workpiece is pulled over it it. By fixing it at a shallow angle, and enabling the blade to be raised up through the bed, the workpiece can be progressively cut by simply pulling it over the blade, then winding it up a little until the final cut length is achieved.

From a construction perspective, the tool is all-metal, built from a collection of the off-the-shelf parts, and thick, hand-cut aluminium alloy plate, nary a CNC tool in sight. The only unusual component is the saw blade itself, which might be a bit tricky to track down if you were so inclined to reproduce the build. It appears (well if you believe the auto-translation by Google Lens, anyway) to be a spare blade for a commercial guide saw available in Japan at least.

We found it particularly pleasing to see the use of a home-built anodizing setup to give it a bit of a jazzy color scheme for some of the plates, just because. Like with many of the build videos from this YouTuber, it is well worth watching all of them, if only just to gather a few ideas for one’s own workspace, if you can stop yourself getting distracted looking at all the other neat tools he uses on the way.

DIY tool builds are not uncommon in these parts, here’s a neat DIY combo table-based project, and here’s a homebrew auto-lowering metal bandsaw which could be a real timesaver.

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