Messaging On Signal Via The ESP32

July 5, 2021 by Zoe Skyforest 15 Comments

Signal is a popular encrypted messaging app, typically used on smartphones. The cross-platform service can now be used via the ESP32, however, thanks to the work of [Dharmik] and [Tirth].

The demonstration is simple, using an ESP32 microcontroller fitted with two push buttons. When one button is pushed, it increments a counter and sends a Signal message noting the current count. The other button sends an image as a Signal message.

The project relies on a Signal bot to deliver an API key that enables the project to work. Messages are sent by making HTTP requests with this key to the CallMeBot.com server. With the API key as authentication, users can only send messages to their own number, keeping the system safe from spammers.

While the demonstration is basic, it merely serves to illustrate how the project works. The aim was to allow home automation and other Internet of Things systems to send Signal messages, and through this method, it’s now possible. The highly security conscious likely won’t want to rely on a random third party server, but for those tinkering around, it may not be such a big deal.

The Internet of Things has a long history with self-messaging projects; we featured the Twittering Toaster back in 2008! Video after the break.

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Could Airships Make A Comeback With New Hybrid Designs?

July 1, 2021 by Zoe Skyforest 101 Comments

Airships. Slow, difficult to land, and highly flammable when they’re full of hydrogen. These days, they’re considered more of a historical curiosity rather than a useful method of transport.

Hybrid Air Vehicles are a UK-based startup working to create a modern take on the airship concept. The goal is to create cleaner air transport for short-hop routes, while also solving many of the issues with the airship concept with a drastic redesign from the ground up. Their vehicle that will do all this goes by the name of Airlander 10. But is it enough to bring airships back to the skies?

A Hybrid Technology

Airlander 10 seen taking off during its first flight.

The Airlander 10 is not a lighter-than-air craft like traditional airships. Instead, the vehicle uses the buoyancy from its helium envelope to create only 60-80% of its lift. The rest of the left is generated aerodynamically by air passing over the eliptical shape of the airship’s body. This lift can also be further augmented by two diesel-powered ducted fans on the sides of the airship, which can pivot to assist with takeoff and landing. Two further fixed ducted fans on the rear provide the primary propulsion for the craft.

The hybrid approach brings several benefits over the traditional airship model. Chief among them is that as the Airlander 10 is heavier than air, it need not vent helium throughout flight to avoid becoming positively buoyant as fuel burns off, nor does it need to vent helium to land. However, it still maintains the capability to loiter for incredibly long periods in the sky as it needs to burn very little fuel to stay aloft. Reportedly, it is capable of five days when manned, and even longer durations if operated in an unmanned configuration. Using helium for lift instead of solely relying on engine thrust and wings means that it is much more fuel efficient than traditional fixed-wing airliners. The company’s own estimates suggest the Airlander 10 could slash emissions on short-haul air routes by up to 90%. The gentle take-off and landing characteristics also mean the vehicle doesn’t require traditional airport facilities, making it possible to operate more easily in remote areas, on grass, sand, or even water. Continue reading “Could Airships Make A Comeback With New Hybrid Designs?” →

China’s Mars Rover Goes Exploring

June 30, 2021 by Zoe Skyforest 20 Comments

China’s space program has big goals and is already starting to achieve them. Recently, the China National Space Administration has landed its first rover on Mars, and begun to explore the surface of the red planet.

It’s a huge step, and something only previously achieved successfully by NASA. Let’s take a look at the Chinese project, its goals, and see how it compares to the American rovers that have also roamed so far away.

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Retrofitting Fast Charging To A Nissan Leaf EV

June 28, 2021 by Zoe Skyforest 21 Comments

Electric cars have been around for a while now, and thus they’re starting to get chopped up and modded just like any other car. [Daniel Öster] is one such person doing the work, and recently posted his efforts to retrofit fast charging to an base-model Nissan Leaf that didn’t ship with the feature.

[Daniel] uses special high-voltage insulated tools when working on EVs for safety.

It’s an involved swap, requiring the substitution of several parts and surgery on the wiring loom. Cost of components was just 700 euros but the swap required 20 hours of labor. The vehicle in question is an early model Leaf that was already fitted with an upgraded 40 kWh battery, and the owner desired an upgrade to CHAdeMO fast charging to better use the larger pack.

The swap required the power distribution unit to be replaced, and the CHAdeMO port to be installed in the front of the car. The vehicle control module (VCM) also had to be opened in order to run a wire to a relay to activate the fast charging subsystem. Finally, wires had to be spliced to get everything to play nicely between the car and the fast charger.

[Daniel] had the benefit of quality forum resources and a Nissan Leaf that already had CHAdeMO to reference, which helped a lot. At the end of the day, the fast charger worked first time, much to [Daniel]’s relief. We’ve featured his work before, too. Video after the break.

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Turning A MIG Welder Into A Metal 3D Printer

June 27, 2021 by Zoe Skyforest 70 Comments

Metal 3D printers are, by and large, many times more expensive than their FDM and resin-based brethren. It’s a shame, because there’s plenty of projects that would benefit from being able to produce more heat-resistant metal parts with additive fabrication methods. [Integza]’s rocketry projects are one such example, so he decided to explore turning a MIG welder into a 3D printer for his own nefarious purposes. (Video, embedded below.)

The build is as simple as you could possibly imagine. A plastic adapter was printed to affix a MIG welding nozzle to an existing Elegoo Neptune 2 3D printer. Unfortunately, early attempts failed quickly as the heat from the welding nozzle melted the adapter. However, with a new design that held the nozzle handle far from the hot end, the ersatz metal 3D printer was able to run for much longer.

Useful parts weren’t on the cards, however, with [Integza] facing repeated issues with the steel bed warping from the heat of the welding process. While a thicker steel base plate would help, it’s likely that warping could still happen with enough heat input so more engineering may be needed. It’s not a new concept by any means, and results are typically rough, but it’s one we’d like to see developed further regardless.

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Coding A Custom Driver For The Adafruit Mini Thermal Printer

June 26, 2021 by Zoe Skyforest 6 Comments

Thermal printers are cool… or, uh, warm actually. They use heat to make images, so they never need ink and they print on receipt rolls. The thermal printer available from Adafruit is a particularly tasty example, as it comes fully documented for the budding hacker. [Ed] is one such person, who set about writing his own driver to use the hardware with Linux on a Raspberry Pi.

The project came about as [Ed] didn’t like the halftone output from the standard Adafruit CUPS driver. Thus, a dithering-capable driver was needed instead. The first step of the project was to get dithering working via running such an algorithm into a custom driver, as well as to vary the heating time of the print head to gain greyscale capability. From there, the driver was integrated with CUPS and could be used with the Linux lp command. Finally, measures to deal with the paper running out were coded in as well.

It’s a fun dive into the nitty-gritty of talking to printers at the low level, something that few of us think about when printing concert tickets in a rush. There’s a lot that goes on to get a page to print successfully, and [Ed]’s work leaves us more respect for everything that goes on to get an image on the paper. The driver is available for keen tinkerers over at Github.

Meanwhile, consider a thermal printer for all your banner-printing needs.

Casting A Simple 3D Print In Aluminium

June 25, 2021 by Zoe Skyforest 21 Comments

3D printing with plastics and resins is great for quickly prototyping parts with all manner of geometries, but strength and durability of the parts produced is often limited. One way around this is to use your 3D printed parts as patterns for casting in something tougher like aluminium. That’s precisely what [Brian Oltrogge] did to produce an attractive wall hook from a 3D printed design.

The process starts with the design and printing of a wall hook, with [Brian] taking care to include the proper draft angles to allow the pattern to be properly removed from the mold. The print is carefully sanded down and post-processed to be highly smooth, so that it doesn’t spoil the mold when its removed for the casting process. From there, a sand casting mold is built around the pattern using sodium silicate in a 3-4% mix by weight with fine masonry sand. Once ready, the pattern is removed, and the mold is assembled, ready for the pour.

[Brian] completes the process with a simple gravity casting method using molten aluminium. The part is then removed from the mold, and filed down to improve the surface finish from the sand casting process. It’s then polished up to a nice shine and hung on the wall.

[Brian] does a great job of explaining the basics of what it takes to get gravity casting right; draft angles in particular are something often ignored by beginners, yet are crucial to getting good results. You needn’t just settle for casting inanimate objects though; we’ve featured DIY casting processes for gears before, too. Video after the break.

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