[FacelessTech] was recently charmed by one of our prized possessions as a kid — the Magic 8-Ball — and decided to have a go at making a digital version. Though there is no icosahedron or mysterious fluid inside, the end result is still without a doubt quite cool, especially for a project made on a whim with parts on hand.
It’s not just an 8-ball, it also functions as a 6-sided die and a direct decider of yes/no questions. Underneath that Nokia 5110 screen there’s an Arduino Pro Mini and a 3-axis gyro. Almost everything is done through the gyro, including setting the screen contrast when the eight ball is first powered on. As much we as love that aspect, we really like that [FacelessTech] included a GX-12 connector for easy FTDI programming. It’s a tidy, completely open-source build, and there’s even a PCB. What’s not to like? Be sure to check out the video after the break to see it in action.
As cool as sculptural LED cubes are, the only thing you can really do is look at them. They’re not going to stand up to a lot of handling, and as tedious as it is to bend all those leads when building them, you probably wouldn’t want to mess with them anyway.
As you will see in the excellent build video that makes this build look challenging instead of impossible, the cube gets permanently sealed up with solder joints. Most but not all of these transfer power, ground, and data around the faces.
Once the cube is together, [moekoe] uses pogo pins to program it, and can charge the little LiPo inside through contact pads. We love the idea of using a cubical printed jig to help solder the PCB edges together, but not as much as we love [moekoe]’s home-brewed SMT soldering setup.
There’s a new development board in town from Adafruit, and it’s called the CLUE. This tiny board can be programmed in Arduino or CircuitPython, and it is absolutely stuffed with sensors and functionality, including Bluetooth. It’s essentially a BBC Micro:bit with more sensors, a screen, and a much beefier processor. Sound interesting? Let’s get out the magnifying glass and take a look, shall we?
(Editor’s note: Adafruit ran out of the first alpha run of the hardware. While we didn’t run into any bugs, the next versions will presumably have even fewer, but will also cost $40 instead of $30. That said, they’re giving out 3,000 of them to attendants of PyCon in April, so you might also get your hands on one that way.)
First and foremost, there’s the form factor — if that bottom edge looks familiar, that’s because the CLUE is designed to work with micro:bit robot kits and anything else with that edge connector, like the CRICKIT for micro:bit, or the Bit:Bot from Seeed Studios. This is big news for the micro:bit ecosystem, and not just because the CLUE brings tons of sensors and a screen to the scene, although a 1.3″ screen at 240×240 resolution is nothing to sneeze at.
The main brain is a Nordic nRF52840, so you can pair it to your phone and stream your collected data. Or, use it to get two CLUE boards talking to each other. This is a major upgrade from the micro:bit’s nRF51822 — the CLUE is four times faster, has four times the flash memory, and has sixteen times as much RAM. We hope someone can find a way to make them into short-range messaging machines with Q10 keyboards.
Your garden variety car generally comes with four wheels, plus a spare in the boot. It’s a number landed upon after much consideration, with few vehicles deviating from the norm. That doesn’t mean there aren’t other possibilities however, and [RCLifeOn] decided to experiment in just such a manner.
The result is a gyro-stabilized two-wheeled RC car, or as we might have put it, a motorcycle of sorts. A brushless motor drives the rear wheel, while steering up front is handled by a servo controlling the front wheel. A large spinning disc acts as a gyro in the center of the vehicle, and it’s all packaged in a simple 3D printed frame.
Results are impressive, with the gyro making a demonstrable difference to the vehicle’s performance. While it can be driven without the gyro enabled, it requires continual steering corrections to stay upright. With the gyro spun up, it rides much more like a bicycle, with few stability issues.
There’s no doubting the wonders that micro-electromechanical systems (MEMS) technology have brought to the world. With MEMS chips, your phone can detect the slightest movement, turning it into a sensitive sensor platform that can almost anticipate what you’re going to do next. Actually, it’s kind of creepy when you think about it.
But before nano-scale MEMS inertial sensing came along, lots of products needed to know their ups from their downs, and many turned to products such as this vibrating piezoelectric gyroscope that [Kerry Wong] found in an old camcorder. The video below shows a teardown of the sensor, huge by MEMS standards but still a marvel of micro-engineering. The device is classified as a Coriolis vibratory gyroscope (CVG) which, as the name implies, uses the Coriolis effect to sense rotation. In this device, [Kerry] found that a long, narrow piezoelectric element spans the long axis of the sensor, suspended from what appears to be four flexible arms. [Kerry] probed the innards of the sensor while powered up and discovered a 22 kHz signal on the piezo element; this vibrates the bar in one plane so that when it rotates, it exerts a force on the support arms that can be detected. Indeed, [Kerry] hooked the output of the sensor to a wonderfully old-school VOM whose needle wiggled with the slightest movement of the sensor.
Sadly, MEMS made this kind of sensor obsolete, but we appreciate the look under the hood. And really, MEMS chips are using the same principle to detect motion, just on a much smaller scale. Want the MEMS basics? [Al] has you covered.
Sometimes a successful project isn’t only about making sure all the electrons are in the right place at the right time, or building something that won’t collapse under its own weight. A lot of projects involve a fair amount of social engineering to be counted as a success, especially those that might result in arrest and incarceration if built as originally planned. Such projects are often referred to as “the fun ones.”
For the past few months, we’ve been following [Bitluni]’s DIY electric scooter build, which had been following the usual trajectory for these things – take a stock unpowered scooter, replace the rear wheel with a 250 W hub motor, add an ESC, battery, and throttle, and away you go. Things took a very interesting turn, however, when his street testing ran afoul of German law, which limits small electric vehicles to a yawn-inducing 6 kph. Unwilling to bore himself to death thus, [Bitluni] found a workaround: vehicles that are only assisted by an electric motor have a much more reasonable speed limit of 25 kph. So he added an Arduino with a gyro and accelerometer module and wrote a program to only power the wheel after the rider has kicked the scooter along a few times – no throttle needed. The motor stops after a bit, needing another push or two to kick it back on. A brake lever kills the motor, as does laying the scooter on its side. It’s quite a clever design, and while it might not keep the Polizei at bay, you can’t say he didn’t try.
Everyone remembers popping their first wheelie on a bike. It’s an exhilarating moment when you figure out just the right mechanics to get balanced over the rear axle for a few glorious seconds of being the coolest kid on the block. Then gravity takes over, and you either learn how to dismount the bike over the rear wheel, or more likely end up looking at the sky wondering how you got on the ground.
Had only this wheelie cheating device been available way back when, many of us could have avoided that ignominious fate. [Tom Stanton]’s quest for the perfect wheelie led him to the design, which is actually pretty simple. The basic idea is to apply the brakes automatically when the bike reaches the critical angle beyond which one dares not go. The brakes slow the bike, the front wheel comes down, and the brakes release to allow you to continue pumping along with the wheelie. The angle is read by an accelerometer hooked to an Arduino, and the rear brake lever is pulled by a hobby servo. We honestly thought the servo would have nowhere near the torque needed, but in fact it did a fine job. As with most of [Tom]’s build his design process had a lot of fits and starts, but that’s all part of the learning. Was it worth it? We’ll let [Tom] discuss that in the video, but suffice it to say that he never hit the pavement in his field testing, although he appeared to be wheelie-proficient going into the project.