Homebuilt Onewheel Uses Hoverboard Parts

March 8, 2020 by Lewin Day 6 Comments

Since Back To The Future II first screened back in 1989, people have been waiting for hoverboards to become reality. Instead, we got a dangerous two-wheeled contraption going by the same name. Wanting something a little cooler, [Bartek Plonek] decided to convert his to a one-wheel design. (Video, embedded below.)

The hack starts by machining the hub motors of the hoverboard. They’re bolted together, and used as the hub of a single larger wheel. Care is necessary to avoid cracking the motor housing during this process, as [Bartek] found during his first attempt. The wheel is then fitted to the centre of a steel frame, upon which two halves of a skateboard are attached to act as a footplate. The original hoverboard controller is still used; we’d love to know if firmware modification was required to work with the new motor configuration.

It’s a classic garage hack that results in a viable personal electric vehicle. Plus, cornering is far easier, with the DIY onewheel capable of carving back and forth quite well. We’ve seen others aim to commute using similar builds.

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Tiny Duck Hunt Looks Like Big Fun

March 8, 2020 by Kristina Panos 5 Comments

Unless you’ve held on to an old tube TV, did the hack that lets you use a light gun with an LCD via Wiimote receiver and a couple of microcontrollers, or live close to one of those adult arcades, you might be really jonesing to play Duck Hunt by now. It’s time to renew that hunting license, because [Danko] has recreated the game for NodeMCU boards, and it’s open season.

Instead of ducks, you get to shoot cute little Twitter-esque birds of varying sizes and point values, and a tiny cab-over truck if you wish. There’s a 60-second free-for-all, and then time is up and your score is displayed. As a special bonus, there’s no smug dog to laugh at you if don’t hit anything. Be sure to check out the demo and build video after the break.

This pocket console lives on a nicely-wired breadboard for now while [Danko] works on a custom PCB. He’s also planning to add support for Arduboy games in the future, and maybe a joystick instead of a D-pad of buttons.

There are a lot of myths floating around about how the old CRTs read the NES light gun, but our own [Will Sweatman] shot them down in his fascinating Duck Hunt: Reloaded write-up.

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Hackaday Links: March 8, 2020

March 8, 2020 by Dan Maloney 16 Comments

A lot of annoying little hacks are needed to keep our integer-based calendar in sync with a floating-point universe, and the big one, leap day, passed us by this week. Aside from the ignominy of adding a day to what’s already the worst month of the year, leap day has a tendency to call out programmers who take shortcuts with their code. Matt Johnson-Pint has compiled a list of 2020 leap day bugs that cropped up, ranging from cell phones showing the wrong date on February 29 to an automated streetlight system in Denmark going wonky for the day. The highest-profile issue may have been system crashes of Robinhood, the online stock trading platform. Robinhood disagrees that the issues were caused by leap day code issues, saying that it was a simple case of too many users and not enough servers. That seems likely given last week’s coronavirus-fueled trading frenzy, but let’s see what happens in 2024.

Speaking of annoying time hacks, by the time US readers see this, we will have switched to Daylight Saving Time. Aside from costing everyone a precious hour of sleep, the semiannual clock switch always seems to set off debates about the need for Daylight Saving Time. Psychologists think it’s bad for us, and it has elicited a few bugs over the years. What will this year’s switch hold? Given the way 2020 has been going so far, you’d better buckle up.
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A Wireless Controller For The Mostly Printed CNC

March 8, 2020 by Tom Nardi 26 Comments

The Mostly Printed CNC (MPCNC) is an impressive project in its own right, allowing anyone with a 3D printer and some electrical conduit to build their own fairly heavy-duty CNC platform perfect for routing. Customization is the name of the game with the MPCNC, and few machines will look the same when they’re done. But even fewer will feature a control interface nearly as slick as the wireless handset that [Steve Croot] has put together for his.

On the hardware side, the project is fairly straightforward. Inside the 3D printed enclosure is a 4.3″ Nextion touchscreen, a Mega 2560 PRO microcontroller, a nRF24L01 2.4 GHz transceiver, and a 4000 mAh 3.7 V LiPo battery with appropriate charging circuit. Besides the physical toggle switch to turn the handheld on and off, all of the device’s functions are touch controlled. For the receiver side, [Steve] is using another nRF24L01 radio and microcontroller pair to toggle relays and shuffle the appropriate G-code commands around.

But what really makes this project shine is the software. As you can see in the video after the break, [Steve] has done an absolutely phenomenal job with the user interface on this controller. The themed boot screen and concise iconography give the controller a very professional look, and the ability to jog the machine around using taps on a virtual workspace helps keep the touch interface from being a gimmick.

We’ve seen some impressive custom-built CNC controllers over the years, but between the mostly off-the-shelf hardware used and impressive UI, we think [Steve] has created something unique. It looks like he’s keeping the source code to himself for the time being, but hopefully he sees fit to release it in the future; a project of this caliber deserves to become more than a one-off creation.

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Bus Sniffing Leads To New Display For Vintage Casio

March 8, 2020 by Tom Nardi 11 Comments

Despite his best efforts to repair the LCD on his Casio FX-702P, it soon became clear to [Andrew Menadue] that it was a dead-end. Rather than toss this relatively valuable device in the trash, he wondered if would be possible to replace the LCD with a more modern display. Knowing that reverse engineering the LCD panel itself would be quite a challenge, he decided instead to focus his efforts on decoding the communications between the calculator’s processor and display controller.

With his logic analyzer connected to the Casio’s four bit bus [Andrew] was able to capture a sequence of bytes during startup that looked promising, although it didn’t quite make sense at first. He had to reverse the order of each nibble, pair them back up into bytes, and then consult the FX-702P’s character map as the device doesn’t use ASCII. This allowed him to decode the message “READY”, and proved the concept was viable.

Of course a calculator with a logic analyzer permanently attached to it isn’t exactly ideal, so he started work on something a bit more compact. Armed with plenty of display controller data dumps, [Andrew] wrote some code for a STM32 “Blue Pill” ARM Cortex M3 microcontroller that would sniff and decode the data in near real-time. In the video after the break you can see there’s a slight delay between when he pushes a button and when the corresponding character comes up on the LCD below, but it’s certainly usable.

Unfortunately, the hardware he’s created for this hack is just slightly too large to fit inside the calculator proper. The new LCD is also nowhere near the size and shape that would be required to replace the original one. But none of that really matters. While [Andrew] says he could certainly make the electronics smaller, the goal was never to restore the calculator to like-new condition. Sometimes it’s more about the journey than the destination.

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Robot Fights Fire With IR

March 8, 2020 by Kristina Panos 7 Comments

Fighting fire with robots may take jobs away from humans, but it can also save lives. [Mell Bell Electronics] has built a (supervised) kid-friendly version of a firefighting robot that extinguishes flames by chasing them down and blowing them out.

This hyper-vigilant robot is always on the lookout for fire, and doesn’t waste movement on anything else. As soon as it detects the presence of a flame, it centers itself on the source and speeds over to snuff it out with a fan made from a propeller and a DC motor.

Here comes the science: fire emits infrared light, and hobbyist flame sensors use IR to, well, detect fire. This fire bot has three of these flame sensors across the front that output digital data to what has got to be the world’s smallest Arduino – the ATmega32U4-based PICO board that [Mell Bell] just so happens to sell. Cover your mouth and nose and crawl along the floor toward the break to see how responsive this thing is.

Firefighters aren’t the only brave humans involved in the process of keeping the forests standing, or who feel the rising pressure of automation. Hackaday’s own [Tom Nardi] wrote a piece on a dying breed called fire lookouts that will no doubt ignite your interest.

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Velocity Based Training, With A Camera

March 8, 2020 by Jenny List 3 Comments

In the world of weight training, the buzzword of the moment is VBT, or Velocity Based Training. This involves sensors being used to measure the speed and position of a weight as it moves through each repetition, and thus provide instant feedback for the athlete and glean information from which they can work upon their training routine. Typically the sensors involved may be accelerometers, but [Kris] has taken a different tack using a webcam and machine vision to do the same job.

The barbell has a green disc attached to its end, and the software tracks it and measures the velocity. It issues a warning when the velocity of a repetition drops below a preset level, telling the athlete to stop their set before pushing themselves too far. Under the hood is a Python script and OpenCV, and the write-up in his GitHub repository takes us through its camera calibration to remove the effects of distortion, and set-up. All calibration of distances within the image is made through the known size of the green disc, allowing the software to accurately chart the distance through which it travels.

We’ve not seen a machine vision approach to weight training before, but we have seen one using accelerometers. Maybe this project will re-ignite interest in this field.