That energy storage is a hot topic is hardly a surprise to anyone these days. Even so, energy storage can take a lot of different forms, some of which are more relevant to the utility provider (like grid-level storage), while others are relevant to business and home owners (e.g. whole-house storage), and yet other technologies live in this tense zone between utility and personal interest, such as (electric) vehicle-to-grid.
For utilities a lot of noise is being made about shiny new technologies, such as hydrogen-based storage, while home- and business owners are pondering on the benefits of relying solely on the utility’s generosity with feed-in tariffs, versus charging a big battery from the solar panels on the roof and using the produced power themselves. Ultimately the questions here are which technologies will indeed live up to their promises, and which a home owner may want to invest in.
A spectrum visualizer is always a fun project, but we really liked [Yannick99]’s take on it since it uses seven IN-13 Nixie tubes for the display. The tubes, of course, need high voltage so part of the project is a high voltage power supply. The spectrum part is a little more ordinary using an op amp and an MSGEQ7 filter IC.
The chip feeds a microcontroller and the microcontroller, with a little help, drives the tubes. The results are great, as you can see in the video below. There are several other videos showing the testing and prototyping, too. The MSGEQ7 is a cute chip that offloads the usual FFT logic from the microcontroller. It does all the work and communicates in a very unusual way. You reset the device and then pulse the strobe input. This causes an analog voltage to appear on the output pin corresponding to the 63 Hz band level. Another strobe pulse selects the next band and you just repeat indefinitely, something the microcontroller is good at.
The only issue, of course, is locating IN-13 tubes. They are around if you look for them, but they may not be cheap. Expect to pay about $20 each for them, more or less. We wondered if you could make an LED look-alike replacement. If you are wondering about the lifespan of these tubes, someone’s already done the testing.
We see tons of projects with the infamous “Blue Pill” STM32 boards. They are cheap and plentiful and have a lot of great features, or at least they were before the chip shortage. I recently picked up a “Black Pill”, which is very similar but has an even more powerful processor. For a few bucks, you get an ARM CPU that can run at 100 MHz (but with USB, probably 96 MHz). There’s 512 kB of flash and 128 kB of RAM. There’s a USB type C port, and even a button and an LED onboard. The thing fits on a breadboard and you can program it with a cheap STLink dongle which costs about $10.
The Black Pill module on a breadboard.
Of course, you then have to consider the software. The STM32Cube stuff is a lot to set up and learn but it does let you do just about anything you can imagine. Then there is the STM32Duino plug-in that lets you use it as a beefy Arduino. That works and is easy enough to set up. However, there’s also Mbed. The only problem is that Mbed doesn’t work right out of the box. Turns out, though, it isn’t that hard to set up. I’ll show you how easy it is to get things going and, next time, I’ll show you a practical example of a USB peripheral that uses the mBed RTOS features.
First Steps
Obviously, you are going to need a Black Pill. There are at least two choices but for as cheap as they are there is little reason not to get the STM32F411 version that has more memory. The DIP form factor will fit in whatever breadboard you happen to have and a USB C cable will power the board so unless you are driving a lot of external circuitry, you probably don’t need an external supply.
[PeriscopeFilms] on YouTube has many old TV adverts and US government reels archived on their channel, with some really interesting subjects to dive in to. This first one we’re highlighting here is a 1958 film about NASA Soldering Techniques (Video, embedded below), which has some fascinating details about how things were done during the Space Race, and presumably, continue to be done. The overall message about cleanliness couldn’t really be any clearer if they tried — it’s so critical it looks like those chaps in the film spend far more time brushing and cleaning than actually wielding those super clean soldering irons.
Of particular note are some of the details of wire stripping and jointing with components, such as the use of a hot-wire device to remove the insulation from wire, rather than use the kind of stripper we have lying around that cuts into the insulation and slightly distorts the wire in the process. That just won’t do. If they did have to use a cutting-type stripper, it must be precisely the right size for job, and calibrated daily.
The road to the Moon is paved with calibrated wire strippers.
When soldering a pre-tinned wire to a leaded component, a clamp is required to prevent movement of the wire, as is a thermal shunt on the component lead to protect the delicate component from excess heat. They even specify how much to wrap a wire around a terminal to be soldered, never bending the wire more than 180 degrees.
The bottom line in all this is, is that the work must be as perfect as is possible, as there is very little chance of sending someone up to fix a dodgy soldering job, once the assembly is hurtling around the planet. They call it too much of a science to be called an art and too much art to be called a science, and we can sure appreciate that.
Soundbars are a rather strange category of speaker, most typically used with televisions to add some punch that the drivers crammed into a flatscreen TV simply can’t match. [Matt] of DIY Perks wanted a soundbar that was better suited to use on a computer desk rather than in a loungeroom, and set about creating one.
Regular soundbars aren’t great for a computer desk as they tend to deliver sound directed at one’s chest rather than one’s ears. [Matt]’s design instead angles its speakers slightly upwards, aimed at the user’s head as it should be. The build uses reclaimed wooden flooring for a cheap source of pretty wood that isn’t as ugly or flaky as MDF.
The design acts as a monitor stand and keyboard hutch, raising the screen to a comfortable height for viewing. The speakers themselves are in acoustic enclosures mounted on either side, also helping to provide good stereo separation. A subwoofer is also built into the shelf to add some bass response, with an impressively-neat bass chamber design. Finished off with some LED lights and a USB hub, the design delivers great sound along with a lovely desk environment for getting work done.
Hackers love 7-segment displays, and will gladly wax lyrical about the silly words you can almost spell on them and so on. Less appreciated are their bigger cousins, the fourteen and sixteen segment displays, which get all alphanumeric about things and are thus much easier for humans to read. You can even build the former out of Lego, as [ord] demonstrates.
A look at the mechanism driving the display.
The “segments” are made up of Lego shafts that are pushed up through a yellow matrix of holes when they are switched “on.” A full seven motors are used to make the single-character display work, each one driving two segments. Two Lego Powered Up controller bricks are required to drive everything going on here, making the final design not just mechanically complicated, but electronically complicated as well.
Amusingly, those don’t come cheap, either; the parts total cost of this build is likely somewhere between $50-100 US. You probably don’t want to build an entire scrolling message board using this design, even if it does look resplendent in black and taxi yellow.
Hacking these days means everything from someone guessing your password and spamming your contacts with toxic links, to wide-scale offensive cyberattacks against infrastructure by sophisticated operators backed by nation states. When it comes to hacking satellites, though, [Didelot Maurice-Michel] found himself tangling with some hardware belonging to the European Space Agency.
As part of an event called HackCYSAT, hackers were invited to attack the ESA’s OPS-SAT, a CubeSat intended to demonstrate improved techniques for mission control and more advanced satellite hardware. The computer hardware on board is ten times more powerful than other existing ESA satellites, and aims to take satellite technology on a new leap forward.
