Wireless All The Things!

Neither Tom Nardi nor I are exactly young anymore, and we can both remember a time when joysticks were actually connected with wires to the computer or console, for instance. Back then, even though wireless options were on the market, you’d still want the wired version if it was a reaction-speed game, because wireless links just used to be too slow.

Somehow, in the intervening years, and although we never even really noticed the transition as such, everything has become wireless. And that includes our own hacker projects. Sure, the ESP8266 and other WiFi-capable chips made a big difference, but I still have a soft spot in my heart for the nRF24 chipset, which made at least point-to-point wireless affordable and easy. Others will feel the same about ZigBee, but the point stands: nothing has wires anymore, except to charge back up.

The reason? As this experiment comparing the latency of many different wireless connections bears out, wireless data links have just gotten that good, to the point that the latency in the radio is on par with what you’d get over USB. And the relevant software ecosystems have made it easier to go wireless as well. Except for the extra power requirement, and for cases where you need to move a lot of data, there’s almost no reason that any of your devices need wires anymore.

Are you with us? Will you throw down your chains and go wireless?

Lawny Five Keeps Lawn Mowed, Snow Plowed

Although there’s been considerable excitement over the past half century of a Jetsons-like robotic future, outside of a few niche uses of our day-to-day lives there hasn’t been much in the way of robotic assistants coming to ease our physical household workloads. Sure, robots exist in manufacturing and other industrial settings, but the vast majority of us won’t see a robotic revolution unless we make it for ourselves. To that end, [Jim] has begun construction of a robot that can at least mow his lawn and eventually plow his driveway, among other potential tasks.

The robot, called the Lawny Five, is a tracked vehicle currently under remote control but with a planned autonomous capability. The frame includes a set of caster wheels at the front to take advantage of the differential steering of the tracks, and between everything is where the mower, plow, or other tool can sit. The attachment system is based on a 2″ receiver hitch, allowing the robot to eventually change tools at will while still preserving the usefulness of the tools in their original state. The robotic platform has been tested with the mower on a wet lawn with a 20° slope and showed no signs of struggle (and didn’t damage the grass) so it’s ready to take on more challenging tasks now as well.

With the core of the build out of the way, [Jim] is well on his way to a robotic lawnmower and potentially even an autonomous one, not to mention one with interchangeable tools that he hopes will be put to work in other ways like parking his boat in a small space by his house. For those maintaining a piece of land a little more involved than suburban turfgrass, there are other robotic platforms capable of helping out farmers with things like planting, watering, and weeding.

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Hotshot 3D Printed Hovercraft Is Devastatingly Fast

These days, it’s pretty cheap and easy to build your own little RC hovercraft. [ValRC] demonstrates just that with a hovercraft build that is surprisingly nimble, and fast to boot.

The build started with a design [ValRC] found online. It was simple enough to print and assemble, needing only a pair of a brushless motors, a speed controller, a receiver, and a servo to run the show. The design uses a plastic bag as a skirt, assembled around a 3D printed frame. That proved to be the hardest part of the build, as hot glue didn’t want to play nice with the thin garbage bag.

Even despite the challenges, once assembled, the hovercraft performed well. It readily slid around on a cushion of air, drifting across asphalt with abandon. Upgrades included a better rudder and a skirt made of thicker and more resilient plastic.  The final craft looked mesmerizing as it glided over the smooth concrete of a parking garage with ease.

A hovercraft is, honestly, one of the cooler printable projects for beginners. All you need is a simple design, some powerful motors, and you’re good to go.

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Cessna 208B Grand Caravan Flies Under Remote Control

Reliable Robotics has been working on Unmanned Aircraft Systems (UAS) since its founding in 2017, with a number of demonstrations for the FAA so far as it works towards getting the technology licensed. Most recently, it flew an unmanned Cessna 208B Grand Caravan with a pilot in a ground-based control center. This comes a few years after the company flew a Cessna Skyhawk 172 in a similar manner, demonstrating the functionality of its systems in a fairly small airplane.

Because the pilot is not in the cockpit, the aircraft needs to be equipped with not only the remote controls and camera systems, but also with automation to handle taxiing, take-off, and landings, which is demonstrated in the in-cockpit video provided by Reliable Robotics (also embedded below). Another large part of the automation is dealing with loss of remote control signal (LC2L). Initially this system will be offered only as a retrofit kit for the 9-13 seater, single-prop Cessna 208B, but Reliable Robotics claims that the system is aircraft-agnostic.

Reliable Robotics is focused on remotely piloted cargo flights, as it would save pilots from the stress of constantly traveling and hectic schedules. In addition, the potential loss of a cargo plane would be far less dramatic than an aircraft carrying passengers. That doesn’t mean passenger airplanes won’t eventually use a remote control system like this, but the certification process for something on the order of even a twin turbo-prop Dash 8 passenger plane is likely to be much more involved.

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Variable-Nozzle Ducted Fan Provides Fluid Dynamics Lessons

Any student new to the principles of fluid dynamics will be familiar with Bernoulli’s principle and the Venturi effect, where the speed of a liquid or gas increases when the size of the conduit it flows through decreases. When applying this principle to real-world applications, though, it can get a bit more complex than a student may learn about at first, mostly due to the shortcomings of tangible objects when compared to their textbook ideals. [Mech Ninja] discovered this while developing a ducted fan based around an RC motor.

The ducted fan is meant to be a stand-in for a model jet engine, based around a high-powered motor generally designed for drone racing. Most of the build is 3D printed including duct system, but in order to improve the efficiency and thrust beyond simple ducting, [Mech Ninja] designed and built a variable nozzle to more finely control the “exhaust” of his engine. This system is also 3D printed and can restrict or open up the outflow of the ducted fan, much like a real jet engine would. It uses two servos connected to collars on the outside of the engine. When the servos move the collars, a set of flaps linked to the collars can choke or expand the opening at the rear of the engine.

This is where some of the complexity of real-life designs comes into play, though. After testing the system with a load cell under a few different scenarios, the efficiency and thrust weren’t always better than the original design without the variable nozzle. [Mech Ninja] suspects that this is due to the gaps between the flaps, allowing air to escape and disrupting the efficient laminar flow of the air leaving the fan, and plans to build an improved version in the future. Fluid dynamics can be a fairly complex arena to design within, sometimes going in surprising directions like this ducted fan that turned out better than the theory would have predicted, at least until they accounted for all the variables in the design.

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RF Remote Made Easy

The 433 MHz spectrum is a little bit of an oddball. It’s one of the few areas of the radio spectrum which is nearly universally unlicensed Outside of the US, it’s an open playground for devices that adhere to the power restrictions and other guidelines about best practices. IoT devices operate here, as well as security systems and, of course, remote controls. And, using a few off-the-shelf parts [hesam.moshiri] shows us how to take advantage of this piece of spectrum by designing and building a programmable and versatile 4-channel 433 MHz remote control.

Built around an ATmega8 microcontroller, making it easy to work with Arduino sketches, and with a 2×8 character LCD for ease-of-use when not connected to a computer, the wireless switching device can store up to 80 remote control codes in its EEPROM memory. This was one of the harder parts for [hesam] to sort out, but using structures to store the data for the codes eventually solved the problems. A simple GUI makes using it with whatever remote happens to be on hand fairly straightforward, including the ability to record codes from existing remotes on the fly and also to associate those codes with specific actions.

Schematics and a bill of materials are available on the project’s page, making this fairly accessible to those looking to add some wireless connectivity to a project, home automation system, or IoT device. It’s mainly set up as a switching device, but with some modifications could be put to work doing more complex tasks. The 433 MHz spectrum is an exciting place to be, too, and things like setting up entire security systems using it are not too far removed from a switching device like this.

[Editor’s note: As many mentioned in the comments, 433 MHz is a licensed ham band in the USA (ITU Region 2), so you can’t use it without a license. (Get one, it’s easy.)  In the USA, the equivalent band is at 315 MHz, which is why garage door remotes usually come with a 315/433 choice. Either way, check your local laws before you transmit.]

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Hackaday Prize 2023: OMOTE Universal Remote

A good universal remote can help tame today’s complex home entertainment systems, combining both classic IR and more modern WiFi and Bluetooth connectivity with programmable functions that allow the user to execute multi-step operations with a single button. Unfortunately, programming them often involves the use of clunky proprietary software.

Which is why [Maximilian Kern] has developed the OMOTE. This open source universal remote is powered by the ESP32, and features the usual collection of physical buttons in addition to a 2.8” 320 x 240 touchscreen with a responsive graphical interface that can display more advanced user interfaces. Everything is packed into an ergonomic 3D printed case that gives it an exceptionally professional look.

The remote’s USB-C port can be used to recharge the internal 2,000 mAhA battery, as well as reprogram the ESP32’s firmware via a CH340C serial chip. The battery life is estimated to be about six months given the considerable low-power capabilities of the ESP32, which includes the use of a LIS3DH 3-axis accelerometer to keep the hardware in sleep mode until it’s picked up.

The software side is still in development, so the IR codes for the remote are currently hardcoded and its WiFi capabilities are limited to MQTT. But in the future, [Maximilian] imagines a web-based configuration interface that runs on the ESP32 and lets you add codes and setup the remote via your phone or desktop.

It looks like the hardware is more or less complete, so presumably the focus from here on out will be bringing the software across the finish line. Don’t worry, there’s still plenty of time — since it’s an entry into the Gearing Up challenge of the 2023 Hackaday Prize, the judges won’t pick the finalists until August 8th.

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