Raspberry Pi 4 Benchmarks: 32- Vs 64-bits

January 28, 2020 by 58 Comments

[Matteo] bought a new Raspberry Pi 4. Why not? You get a quad-core ARM processor, up to 4 GB of RAM, and a gigabit Ethernet port for $35 $35-55. However, the default operating system is still a 32-bit system and doesn’t take advantage of the Pi 4’s 64-bit capable CPU. So he installed a light version of 64-bit Debian and ran some benchmarks for the Raspberry Pi 4 running both 32-bit and 64-bit operating systems.

It really shouldn’t be surprising that the 64-bit OS did better in nearly every test. If anything is surprising, it may be that the difference is so pronounced. Some of the benchmarks, like Dhrystones, probably don’t relate much to real-life usage. But some things, like computing a hash, is something you probably do pretty often in normal usage, and the timing difference is pronounced.

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New Part Day: SK6812 Mini-E. A Hand Solderable Neopixel Compatible LED!

January 28, 2020 by 23 Comments

Normally when we give you a New Part Day piece, it concerns a component that you will have never seen before. The subject of this find by [Robert Fitzsimons] then is a slight departure from that norm, given that the SK6812 Mini-E is a WS2812 or Neopixel compatible multi-colour LED of a type that has been available for a while now.

What makes this component new though is its packaging. The Mini-E variant of the SK6812 only appeared last year and has now found its way through to smaller order quantities on AliExpress. Its special feature is that it has a set of flat leads rather than the usual pads on the underside of the package. This means that unlike its predecessors it is readily hand solderable, as he demonstrates by attaching a set of leads to one.

The leads emerge halfway up the side of the device, which seems designed to be mounted recessed within a PCB hole. He demonstrates this with a piece of stripboard, and remarks that they would make a good choice for many small projects such as Shitty Add-On boards.

We’ve touched the leadless SK6812s a few times before, along the way remarking that in some respects they are better than the WS2812 they follow.

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A Miniature Laptop You Can Build Yourself

January 27, 2020 by 15 Comments

Over the last couple of years, we’ve seen more and more hackers building their own custom computers. We’re not just talking casemods here; enabled by advancements in desktop 3D printing and increasingly powerful boards such as the Raspberry Pi 4, these are machines designed and built from the ground up to meet the creator’s particular set of needs and desires.

A perfect example of this trend is the Rasptop 2.0, a remarkably practical design for a 3D printed miniature laptop. Despite the name, you don’t even need to use the Raspberry Pi if you don’t want to. Creator [Morgan Lowe] has designed the Rasptop to take other single board computers (SBCs) such as the Asus Tinker Board or even the Intel Atom powered Up Board. So whether you want an energy efficient ARM machine running Linux for development, or a mobile Windows box for on the go gaming, you can use the same printed parts.

At the most basic level, the Rasptop 2.0 is just a hollow box with a hinged compartment for a screen mounted on top. You’re free to equip it with whatever hardware you chose. If you’re after maximum runtime you could fill all the free space with batteries, or maybe install multiple hard drives if you’re a data horder in need of a mobile terminal. Even the various SBCs that [Morgan] has tested are really just suggestions. The choice is yours.

Perhaps also our favorite feature of the Rasptop is how he worked a keyboard into the design. Rather than just leaving a big rectangle in the STL for you to shove a mobile keyboard into, the top surface is designed to mount the PCB and membrane keypad of one of those mini wireless keyboards you see on all the import sites. Aside from the fact it’s a good deal chunkier than what we expect from modern mobile devices, it has a very finished and professional overall look.

Of course if you’d rather use all these powerful tools to build a computer that’s somewhat farther off the beaten track, your design could abandon the traditional computer form factors altogether.

The Options For Low Cost ROV Tethers

January 27, 2020 by 22 Comments

Wireless connections are cool and all, but sometimes you just need a bit of copper. This interesting article on SV Seeker discusses the various ways of making a tether for a remotely operated vehicle (ROV). They experimented with a number of different cables, including gel-filled Cat 5 designed for burial and wrapping the cable in polypropylene rope to keep it protected and buoyant. They also looked at using a single core solid coax cable with an Ethernet to coax converter on either end wrapped in stretch webbing. The upside of using coax would be the length: it can handle over a mile of cable, which should be more than enough for this project. The downside is that they found that the coax stretches under strain, messing with the signal.

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Carbide3D Router Teardown And Testing

January 27, 2020 by 6 Comments

On the face of it, you’d think a small router would be pretty simple. After all, what is it other than a spinning motor? However, that motor has to handle some pretty serious torque depending on what you are routing. [Baki1] had his Carbide3D router die in the middle of a project, so he did what any of us would do. He tore it open.

In addition to showing off its insides, he also tried to figure out what was wrong with it. It looks like a blown triac was the culprit, and we assume that part 2 will be the repair and how that actually worked out.

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One Chip Does It All In This MacGuyver Synth

January 27, 2020 by 33 Comments

When you think of simple synths, what components come to mind? All you really need to make one is an oscillator, an amplifier, and some kind of input such that you can play different notes. Our favorite go-to for churning out square waves is probably the 40106 IC, which has six inverting Schmitt triggers, and then usually a 386 to amplify the output.

But it’s possible to go even simpler than that, and school is in session with [Jule] giving the lesson. [Jule]’s little analog synth uses a single IC for both the oscillator and the amplifier — a TL072 op-amp. The rest is made of purely discrete components.

[Jule] says those momentary switches are sub-par, and will add a vibrato effect if properly wiggled while pressed. To us, the buttons looks pretty nice, and much easier to jam out with than the ones with 1/8″ diameter actuators. Plus, whenever you press multiple buttons, the additive resistance unlocks the synth’s inner R2D2 voice. We really see no downsides here.

By default, this is an eight-button synth tuned to C major. But there’s a surprise — you can plug different capacitors into a piece of header and change the octave on the fly. Check it out after the break.

Making pitch-correct frequencies requires weird resistor values, which we can usually satisfy with two resistors in series. But wait, what’s up with resistor values, anyway? And why do they have a color code?

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Supercon Keynote: Megan Wachs Breaks Down RISC-V

January 27, 2020 by 17 Comments

The 2019 Hackaday Superconference kicked off with a marvelous, and marvelously geeky, keynote talk on the subject of RISC-V by Dr. Megan Wachs. She is VP of Engineering at SiFive, a company that makes RISC-V processors in silicon, but the talk is a much more general introduction to the RISC-V open instruction-set architecture (ISA) and why you’d care. The short answer to the latter is the same reason you care about any other open standard: it promotes interoperability, reusable toolchains, and will result in us all having access to better and faster CPUs.

The video is embedded below, and it’s absolutely worth a watch. Unfortunately, The video is missing the first few minutes, you can follow along through her slides (PDF) and read through our brief recap below of what fell down the video hole.

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