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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resin printed pulsejet engine in operation

A Detonation Engine Prototyped Using Resin Printing

August 29, 2022 by Dave Rowntree 5 Comments

Over the years [Integza] has blown up or melted many types of jet engine, including the humble pulsejet. Earlier improvements revolved around pumping in more fuel, or forced air intakes, but now it’s time for a bit more refinement of the idea, and he takes a sidestep towards the more controllable detonation engine. His latest experiment (video, embedded below) attempts to dial-in the concept a little more. First he built a prototype from a set of resin printed parts, with associated tubing and gas control valves, and a long acrylic tube to send the exhaust down. Control of the butane and air injection, as well as triggering of the spark-ignition, are handled by an Arduino — although he could have just used a 555 timer — driving a few solid state relays. This provided some repeatable control of the pulse rate. This is a journey towards a very interesting engine design, known as the rotating detonation engine. This will be very interesting to see, if he can get it to work.

supersonic exhaust plume from a pulsejet engine — Supersonic exhaust plume with the characteristic ‘mushroom’ shape

Detonation engines operate due to the pressure part of the general thrust equation, where the action is in the detonative combustion. Detonative combustion takes place at constant pressure, which theoretically should lead to a greater efficiency than boring old deflagration, but the risks are somewhat higher. Apparently this is tricky to achieve with a fuel/air mix, as there just isn’t enough oomph in the mixture. [Integza] did try adding a Shchelkin spiral (we call them springs around here) which acts to slow down the combustion and shorten the time taken for it to transition from deflagration to detonation.

It sort of worked, but not well enough, so running with butane and pure oxygen was the way forward. This proved the basic idea worked, and the final step was to rebuild the whole thing in metal, with CNC machined end plates and some box section clamped with a few bolts. This appeared to work reasonably well at around 10 pulses/sec with some measurable thrust, but not a lot. More work to be done we think.

We hinted at earlier work on forced-air pulsejets, so here that is. Of course, whilst we’re on the subject of pulsejets, we can’t not mention [Colinfurze] and his pulsejet go kart.

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2022 Hackaday Prize: Boondock Echo Connects Your Radios With The Cloud

August 27, 2022 by Dave Rowntree 6 Comments

[Mark J Hughes] volunteers as a part of a local community fire watch which coordinates by radio. The La Habra Heights region of Los Angeles is an area of peaks and valleys, which makes direct radio connections challenging. Repeaters work well for range improvement, but in such areas, there is no good place to locate these. [Mark] says that during an emergency (such as a wildfire) the radio usage explodes, with him regularly tracking as many as eight radio frequencies and trying to make sense of it, whilst working out how to send the information on and to whom.

This led him together with collaborator [Kaushlesh Chandel] to create Project Boondock Echo, to help alleviate some of the stress of it all. The concept is to use a cheap Baofeng radio to feed into a gateway based around an ESP32 audio development kit. Mount this in a box with a LiPo based power supply, and you’ve got yourself a movable radio-to-cloud time-shift audio recorder.

By placing one or more of these units in the properties of several of the community group radio operators, all messages can be captured to an audio file, tagged with the radio frequency and time of transmission, and uploaded to a central server. From there they can be retrieved by anybody with access, no matter the physical location, only an internet connection is needed.

The next trick that can be performed, is to reverse the process and queue up previous recordings, and send it back over the cloud to remote locations for re-transmission via radio into the field. This is obviously a massive asset, because wherever there is some urbanization, there is likely an internet connection. With the addition of a Boondock Echo unit, anyone that has a receiver within a few miles can be fully connected with what’s going on outside the range of direct radio communications.

Source for the ESP32’s firmware as well as the web side of things can found on the project Boondock Echo GitHub, complete with some STLs for a 3D printed box to sit it in. Like always, there’s more than one way to solve a particular problem. Here’s an amateur radio repeater based using an RTL-SDR and a Raspberry Pi.