That’s A Lisp Machine In Your Pocket

Computer languages have always advanced faster than computer hardware. Case in point: we’re just now getting CPU instructions for JavaScript floating point numbers. The 1970s and 80s wasn’t the garbage fire of JavaScript instructions in silicon, instead they were all about garbage collection. Lisp machines were CPUs designed to run Lisp efficiently. They were great, until the companies responsible realized you had to sell a product to stay in business. Combine an interesting architecture with rarity and historical interest, and you have a centerpiece of any retrocomputing enthusiasts collection. Yes, we all want a Lisp machine.

Now there’s an interesting project on CrowdSupply that will make that possible. It’s the MakerLisp Machine, a credit card-sized computer that runs bare-metal Lisp.

We first saw the MakerLisp Machine in its raw prototype form at VCF West last August, and it was in a very, very raw state. That was just a prototype, though, but the MakerLisp business card-sized computer still features the Zilog eZ80 running at 50MHz. The basic board includes a USB port for a serial connection and a microSD card slot for storage. It boots into a Lisp environment, and you don’t even have to use a NuBus card. We’re living in the future here.

Because this is a credit card-sized computer, there is of course an expansion board that breaks everything out, including the GPIOs. Being a Z80, you’re also going to get CP/M support, but the real story here is Lisp, in your pocket.

Can Magnets Replace The Spring In A Pogo Stick?

Betteridge’s law of headlines states that any headline that ends in a question mark can be answered by the word ‘no’. It’s the case with articles asking if Millennials are responsible for all of the world’s ills, or if some technology is the future. So we come to this fascinating case of native content (amusing, veiled advertising) from a store that sells really, really powerful magnets. The title of the article asks if magnets can replace the spring in a pogo stick. The answer, of course, is no, but it does provide a fascinating look at linear versus exponential growth.

A pogo stick is simply a spring with a set of handles and footholds that is the subject of a great number of hilarious YouTube videos, at least one of which is impressive. The physics of a pogo stick is determined entirely by Hooke’s Law, and is a linear equation, not counting the strength of a spring and the yield point of steel, but this is a pogo stick we’re talking about. Magnets, on the other hand, obey the inverse square law. Is it possible to fit an exponential function to fit a linear function? No. No, it is not.

I refuse to believe this is the first use of the phrase, ‘immensely disappointing pogo stick’

But a lack of understanding of the basic forces of nature never stopped anyone, so the folks at K & J Magnetics made a really neat test. They printed out a 1/8th scale pogo stick, complete with a spring. It worked like any pogo stick would. Then they took out the spring and put a few magnets where the spring should go. How did that work? Well, it bottomed out and was an immensely disappointing pogo stick.

If a problem is worth solving, it’s worth solving wrongly, so more magnets were added. Mounting three magnets onto a pogo stick gave the same exponential force, but still not enough. Four, five, and six magnets were added to the model pogo stick, and while six magnets gave this model pogo enough force to be ‘bouncy’, there simply wasn’t enough space for the pogo stick to compress.

The takeaway from this experiment is extremely obvious in retrospect, but probably too subtle for a lot of people. There’s a difference between a linear relationship and and exponential relationship. There’s also a video, you can check that out below.

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A Deep Dive Into Low Power WiFi Microcontrollers

The Internet of Things is eating everything alive, and the world wants to know: how do you make a small, battery-powered, WiFi-enabled microcontroller device? This is a surprisingly difficult problem. WiFi is not optimized for low-power operations. It’s power-hungry, and there’s a lot of overhead. That said, there are microcontrollers out there with WiFi capability, but how do they hold up to running off of a battery for days, or weeks? That’s what [TvE] is exploring in a fantastic multi-part series of posts delving into low-power WiFi microcontrollers.

The idea for these experiments is set up in the first post in the series. Basically, the goal is to measure how long the ESP8266 and ESP32 will run on a battery, using various sleep modes. Both the ESP8266 and ESP32 have deep-sleep modes, a ‘sleep’ mode where the state is preserved, a ‘CPU only’ mode that turns the RF off, and various measures for sending and receiving a packet.

The takeaway from these experiments is that a battery-powered ESP8266 can’t be used for more than a week without a seriously beefy battery or a solar panel. Run times are much longer with an open network as compared to a secured network, and that security eats up a ton of power: connecting to a secure network every now and again means your ESP might only run for a day, instead of a week.

There is another option, though: the ESP32. While the ’32 is vastly more powerful and more capable than the ESP8266, it also has a few improved features that help with power consumption. Importantly, there’s a bug in the ESP8266 where it drops into modem sleep instead of light sleep about half the time. This error was fixed in the ESP32, but all that power does come at a cost. On the whole, if you’re concerned about security, the ESP32 is slightly better, simply because it does the ‘security’ part of connecting to a WiFi network faster. This is really a remarkable amount of testing that’s gone into this write-up, so if you’re developing something battery-powered with any ESP, it’s well worth the read.

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Hackaday Links: December 16, 2018

Microsoft is really leaning into vaporwave these days. Microsoft is giving away knit Windows sweaters to social media influencers. Is it for an ugly sweater contest? Maybe, or maybe Microsoft is capitalizing on the mid-90s AESTHETIC. Recently, Apple got back in their 90s logo game with the release of a few ‘rainbow Apple’ t-shirts. The spirit of the 90s lives on in tech culture.

Have a Hackerspace? Frack is organizing the great Inter-hackerspaces Xmas goodies swap! Since your hackerspace is filled with weird ephemera and random crap, why not box it up and send it out to another hackerspace? You’ll probably get another random box of crap in return!

Just an observation looking for commentary, but is Thingiverse slow these days? It seems really, really, really slow these days.

The Blockchain makes it to the Apple II! By far, the most interesting thing in tech right now is the blockchain, with AI, at the edge. This will get your Merkle trees tinglin’ with some AI, and 5G is where it’s at. We’re back with cylinder computing this time, and this is the greatest achievement that will synthesize brand new paradigms. Of course, if it weren’t for millennials, we’d have it already.

There’s a new portable console out there, and it’s at the top of everyone’s Christmas lists. The SouljaGame Handheld is a rebrand of what’s available on AliExpress. What makes this one different? It has Soulja Boy’s name on it. If you couldn’t get your hands on the SouljaGame Handheld, don’t worry: Post Malone Crocs are available on eBay for about $300.

RISC-V Will Stop Hackers Dead From Getting Into Your Computer

The greatest hardware hacks of all time were simply the result of finding software keys in memory. The AACS encryption debacle — the 09 F9 key that allowed us to decrypt HD DVDs — was the result of encryption keys just sitting in main memory, where it could be read by any other program. DeCSS, the hack that gave us all access to DVDs was again the result of encryption keys sitting out in the open.

Because encryption doesn’t work if your keys are just sitting out in the open, system designers have come up with ingenious solutions to prevent evil hackers form accessing these keys. One of the best solutions is the hardware enclave, a tiny bit of silicon that protects keys and other bits of information. Apple has an entire line of chips, Intel has hardware extensions, and all of these are black box solutions. They do work, but we have no idea if there are any vulnerabilities. If you can’t study it, it’s just an article of faith that these hardware enclaves will keep working.

Now, there might be another option. RISC-V researchers are busy creating an Open Source hardware enclave. This is an Open Source project to build secure hardware enclaves to store cryptographic keys and other secret information, and they’re doing it in a way that can be accessed and studied. Trust but verify, yes, and that’s why this is the most innovative hardware development in the last decade.

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ICEBreaker, The Open Source Development Board For FPGAs

The Hackaday Superconference is over, which is a shame, but one of the great things about our conference is the people who manage to trek out to Pasadena every year to show us all the cool stuff they’re working on. One of those people was [Piotr Esden-Tempski], founder of 1 Bit Squared, and he brought some goodies that would soon be launched on a few crowdfunding platforms. The coolest of these was the iCEBreaker, an FPGA development kit that makes it easy to learn FPGAs with an Open Source toolchain.

The hardware for the iCEBreaker includes the iCE40UP5K fpga with 5280 logic cells,, 120 kbit of dual-port RAM, 1 Mbit of single-port RAM, and a PLL, two SPIs and two I2Cs. Because the most interesting FPGA applications include sending bits out over pins really, really fast, there’s also 16 Megabytes of SPI Flash that allows you to stream video to a LED matrix. There are enough logic cells here to synthesize a CPU, too, and already the iCEBreaker can handle the PicoRV32, and some of the RISC-V cores. Extensibility is through PMOD connectors, and yes, there’s also an HDMI output for your vintage computing projects.

If you’re looking to get into FPGA development, there’s no better time. Joe Fitz‘s WTFpga workshop from the 2018 Hackaday Superconference has already been converted to this iCEBreaker board, and yes, the seven-segment display and DIP switches are available. Between this and the Open Source iCE toolchain, you’ve got a complete development system that’s ready to go, fun to play with, and extremely capable.

How To Stay Grounded When You Have Zero Potential

Ground is an interesting topic when it comes to engineering. Either it’s the reference level for a digital circuit (not necessarily at zero volts, either), or it’s the return path for current, or it’s the metal chassis, which shouldn’t be the return path for current or else something’s terribly broken. Erika Earl’s talk at this year’s Hackaday Superconference is all about ground.

The first type of ground to talk about is the ground in your outlets and walls. The AC safety ground is the third pin on your plug that should be attached to the chassis of your washer/dryer on one end, and somehow connected to the neutral wire somewhere near your breaker box. The theory of this being if a conductor touches the chassis of a lamp or appliance, all the current will go along that ground bus saving you from electrocution. It should also trip the circuit breaker.

But really we’re rarely dealing with mains power around here. When it comes to electronic design, we’re mostly dealing with analog grounds and digital grounds in circuits. Sometimes these are the same, sometimes they’re not, but they’re both usually referenced to 0 Volts, Add in some considerations for EMC, and ground loops, and you have an astonishing amount of knowledge wrapped up in having zero potential.

If you want to know about what ground actually is, this isn’t a talk to miss. Erika has tons of experience chasing down grounds as an audio engineer, and her career highlights including the director of hardware engineering at Slate Digital and the Senior Technical Engineer at LA’s legendary Village Recording Studios. There’s a lot of experience here, and if you want to where to find your ground, Erika is the person to ask.