If you’ve ever been configuring a router or other network device and noticed that you can set up IPv4 and IPv6, you might have wondered what happened to IPv5. Well, thanks to [Navek], you don’t have to wonder anymore. Just watch the video below.
We will warn you of two things. First, the video takes a long time to get around to what IPv5 was. In addition, if you keep reading, there will be spoilers.
You’ve doubtless seen those ubiquitous clock modules, especially when setting clocks for daylight savings time. You know the ones: a single AA battery, a wheel to set the time, and two or three hands to show the time. They are cheap and work well enough. But [Playful Technology] wanted to control the hands with an Arduino directly and, in the process, he shows us how these modules work.
If you’ve never studied the inside of these clock modules, you may be surprised about how they actually work. A crystal oscillator pulses a relatively large electromagnet. A small plastic gear has a magnetic ring and sits near the electromagnet.
Each time the polarity of the electromagnet flips, the ring turns 180 degrees to face the opposite magnetic pole to the electromagnet. This turns the attached gear which is meshed with other gears to divide the rotation rate down to once per 24 hours, once per hour, and once per minute. Pretty clever.
That makes it easy to control the hands. You simply detach the electromagnet from the rest of the circuit and control it yourself. The module he used had a mechanical limitation that prevents the hands from moving well at more than about 100 times normal speed.
We wondered how he made the hands reverse and, apparently, there is a way to get the drive gear to move in reverse, but it isn’t always reliable. Of course, you could also replace the drive mechanism with something like an RC servo or other motor and it sounds like he has done this and plans to show it off in another video.
We’ve seen the opposite trick before, too. If you really want an easy-to-control analog clock, try this one Continue reading “Clock Mechanism Goes Crazy For Arduino”
It’s been a busy week in space news, and very little of it was good. We’ll start with the one winner of the week, Firefly’s Blue Ghost Mission 1, which landed successfully on the Moon’s surface on March 2. The lander is part of NASA’s Commercial Lunar Payload Services program and carries ten scientific payloads, including a GPS/GNSS receiver that successfully tracked signals from Earth-orbiting satellites. All of the scientific payloads have completed their missions, which is good because the lander isn’t designed to withstand the long, cold lunar night only a few days away. The landing makes Firefly the first commercial outfit to successfully soft-land something on the Moon, and being the first at anything is always a big deal.
Small cylindrical parts are often formed through deep drawing — a process by which a punch forms the finished piece from a flat sheet of metal using a forming die. If it sounds like that stresses the metal, it does. But researchers at Fraunhofer have found a way to reduce friction protecting both the material and the tools that do the forming. The process — known as VibroDraw — uses ultrasonic vibrations at around 500 Hz.
Researchers claim a 20% reduction in friction now, and it may be possible to go even further. With less friction, it is possible to do a deeper draw in a single stage. It also creates less heat which is good for tool life and prevents overheating lubricant. The process has a patent if you want more details. You might need to brush up on your German, though. Unsurprisingly, the vibrations are from a piezoelectric transducer.
Copper is soft enough to use 3D printed dies. We don’t know if this technique would help with that or not. Then there’s hydroforming. If you have any results using ultrasonics with these or any other techniques, be sure to let us know.
What would you do with dozens and dozens of outdated Chromebooks that are no longer getting updates from the Google Mothership? It’s a situation that plenty of schools will have to deal with in the near future, and we can only help that those institutions have students as clever as [Varun Biniwale] and his friend [Aksel Salmi] to lean on — as they managed to recycle ten of these outdated laptops into an impressive video display.
There’s actually two write-ups for this particular story, with [Varun] documenting the modification of the Chromebooks and the software developed to play the video between them, and [Aksel] covering how the hardware was ultimately attached to the wall via bespoke 3D printed mounting brackets.
Continue reading “Old Chromebooks Get Second Life As Video Wall”
Getting a robot to stand on two wheels without tipping over involves a challenging dance with the laws of physics. Self-balancing robots are a great way to get into control systems, sensor fusion, and embedded programming. This build by [mircemk] shows how to make one with just a few common components, an Arduino, and a bit of patience fine-tuning the PID controller.
At the heart of the bot is the MPU6050 – a combo accelerometer/gyroscope sensor that keeps track of tilt and movement. An Arduino Uno takes this data, runs it through a PID loop, and commands an L298N motor driver to adjust the speed and direction of two DC motors. The power comes from two Li-ion batteries feeding everything with enough juice to keep it upright. The rest of the magic lies in the tuning.
PID (Proportional-Integral-Derivative) control is what makes the robot stay balanced. Kp (proportional gain) determines how aggressively the motors respond to tilting. Kd (derivative gain) dampens oscillations, and Ki (integral gain) helps correct slow drifts. Set them wrong, and your bot either wobbles like a confused penguin or falls flat on its face. A good trick is to start with only Kp, then slowly add Kd and Ki until it stabilizes. Then don’t forget to calibrate your MPU6050; each sensor has unique offsets that need to be compensated in the code.
Once dialed in, the result is a robot that looks like it defies gravity. Whether you’re hacking it for fun, turning it into a segway-like ride, or using it as a learning tool, a balancing bot is a great way to sharpen your control system skills. For more inspiration, check out this earlier attempt from 2022, or these self-balancing robots (one with a little work) from a year before that. You can read up on [mircemk]’s project details here.
SD cards & the much smaller microSD cards are found on many devices, with the card often accessible from outside the enclosure. Unfortunately there’s a solid chance that especially small microSD cards will find their way past the microSD card reader slot and into the enclosure. This is what happened to [Rob] of the SevenFortyOne Radios and Repairs channel on YouTube with a NanoVNA unit. While shaking the unit, you can clearly hear the microSD card rattling inside, courtesy of the rather large gap above the card slot.
After a quick teardown and extracting the lost microSD card, the solution to prevent this is a simple bit of foam stuck on top of the microSD card slot, so that the too large opening in the enclosure is now fully blocked. It’s clearly a bit of a design fail in this particular NanoVNA unit, worsened by the tiny size of the card and having to use a fingernail to push the card into the slot as it’s so far inside the enclosure.
While [Rob] seems to blame himself for this event, we’d chalk it mostly up to poor design. It’s an issue that’s seen with certain SBC enclosures and various gadgets too, where losing a microSD card is pretty much a matter of time, and hugely fiddly at the best of times. That said, what is your preferred way of handling microSD card insertion & removal in devices like these?
Continue reading “Fixing An Unpleasant SD Card Slot Issue In A NanoVNA”