ERRF 18: Slice Engineering Shows Off The Mosquito

July 11, 2018 by Tom Nardi 26 Comments

With few exceptions, it seemed like every 3D printer at the first inaugural East Coast RepRap Festival (ERRF) was using a hotend built by E3D. There’s nothing inherently wrong with that; E3D makes solid open source products, and they deserve all the success they can get. But that being said, competition drives innovation, so we’re particularly interested anytime we see a new hotend that isn’t just an E3D V6 clone.

The Mosquito from Slice Enginerring is definitely no E3D clone. In fact, it doesn’t look much like any 3D printer hotend you’ve ever seen before. Tiny and spindly, the look of the hotend certainly invokes its namesake. But despite its fragile appearance, this hotend can ramp up to a monstrous 500 C, making it effectively a bolt-on upgrade for your existing machine that will allow you to print in exotic materials such as PEEK.

We spent a little time talking with Slice Engineering co-founder [Dan], and while there’s probably not much risk it’s going to dethrone E3D as the RepRap community’s favorite hotend, it might be worth considering if you’re thinking of putting together a high-performance printer.

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SPIDriver Shows You What’s Going On

July 10, 2018 by Elliot Williams 17 Comments

When you’re debugging two bits of electronics talking SPI to each other, there’s a lot that can go sideways. Starting from the ground up, the signals can be wrong: data not synced with clocks right, or phase inverted. On top of that, the actual data sent needs to make sense to the receiving device. Are you sending the right commands?

When nothing’s working, you’re fighting simultaneously on these two fronts and you might need different tools to debug each. An oscilloscope works great at the physical layer, while something like a Bus Pirate or fancier logic analyzer works better at the data layer because it can do parsing for you. [James Bowman]’s SPIDriver looks to us like a Bus Pirate with a screen — giving you a fighting chance on both fronts.

SPIDriver also has a couple more tricks up its sleeve: a voltage and current monitor for the device under test, so you don’t even have to break out your multimeter when you’re experiencing random resets. We asked [James] if these additions had a sad history behind them. He included this XKCD.

Everything about SPIDriver is open, so you can check out the hardware design, browse the code, and modify any and all of it to your taste. And speaking of open, [James] is also the man behind the Gameduino and an amazing FPGA Forth soft-CPU.

It’s fully crowd-funded, but it closes in a couple of days so if you want one, get on it soon.

And if you want to learn more about SPI debugging, we’ve written up a crash-course. With the gear and the know-how, you at least stand a fighting chance.

A Peek Into A Weed-Eating Robot’s Test Fixtures

July 7, 2018 by Donald Papp 2 Comments

When it comes to production, fast is good! But right the first time is better. Anything that helps prevent rework down the line is worth investing in. Some of the best tools to catch problems are good test fixtures. The folks at Tertill (a solar-powered robot for killing weeds that kickstarted last year) took the time to share two brief videos of DIY test fixtures they use to test components before assembly.

The videos are short, but they demonstrate all the things that make a good test: on the motor tester there are no connectors or wires to fiddle with, the test starts automatically, and there is clear feedback via prominent LEDs. The UI board tester also starts automatically and has unambiguous LED feedback, and sports a custom board holder with a recess just the right shape for the PCB. Once the board is in, the sled is pushed like a drawer to make contact with the test hardware and begin the test. The perfectly formed recesses in both units serve another function as well; they act as a go/no-go test for the physical shape of the components and contacts being tested.

Both videos are embedded below; and while there isn’t much detail on the actual test hardware, we do spy a Raspberry Pi and at least two Adafruit logos among other hacker-familiar elements like laser-cut acrylic, 3D printed plastic, pogo pins, and a PVC junction box.

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Nintendo Switch Gets Internal Trinket Hardmod

July 1, 2018 by Tom Nardi 51 Comments

If you haven’t been following the Nintendo Switch hacking scene, the short version of the story is that a vulnerability was discovered that allows executing code on all versions of the Switch hardware and operating system. In fact, it’s believed that the only way to stop this vulnerability from being exploited is for Nintendo to release a new revision of the hardware. Presumably there are a lot of sad faces in the House of Mario right about now, but it’s good news for us peons who dream of actually controlling the devices we purchase.

To run your own code on Nintendo’s latest and greatest, you must first put it into recovery mode by shorting out two pins in the controller connector, and then use either a computer or a microcontroller connected to the system’s USB port to preform the exploit and execute the binary payload. It’s relatively easy, but something you need to do every time you shut the system down. But if you’re willing to install an Adafruit Trinket M0 inside your Nintendo Switch, you can make things a little easier.

Stemming from work done by [atlas44] and [noemu], the final iteration of this mod was created by [Quantum-cross]. The general idea is to strip down the Trinket M0 board to as small as possible by removing the USB port and a few capacitors, and then install it inside the Switch’s case. By wiring it up to power, the back of the USB-C connector, and the controller connector, the Trinket can interact with all the key components involved in the exploit.

You can even use the Switch’s USB port to update the firmware on the Trinket to load different payloads, though in his walkthrough video after the break, [xboxexpert] mentions eventually this won’t really be necessary as the homebrew software environment on the Switch matures. Indeed, there will almost certainly come a time when performing this exploit on every boot of the system will be made unnecessary, rendering this modification obsolete. But until then, this is a pretty slick way of getting your feet wet in the world of Switch hacking.

It was only six months or so back that we were reading about the first steps towards running arbitrary code on the Nintendo Switch, and just a few months prior to that we saw people experimenting with controlling the system with a microcontroller.

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This Year, Badges Get Blockchains

June 28, 2018 by Brian Benchoff 11 Comments

This year’s hottest new advance in electronics comes through wearable badges. You can’t have failed to notice another technology that’s getting really hot. It’s the blockchain. What is a blockchain? It’s a linked list where every item in the list contains a cryptographic hash of the previous item in the list. What is a blockchain in English? It’s the most revolutionary technology that’s going to solve every problem on the planet, somehow. It’s the basis for crypto (no not that one, the other one). The blockchain is how you add more Lamborghinis to your Lamborghini account. Even though we’re still trying to figure out how it solves a single problem, one thing is certain: blockchains solve every problem. We were born too late to explore the Earth, born too early to explore the Universe, but just in time for blockchain.

Independent badges are always looking at the latest technology, and perhaps this was inevitable. It’s a badge built on the blockchain. It’s a wearable sneakernet of mining. It’s a game with collaborative proof of work.

The blockchain badge from [Mr Blinky Bling] is an independent badge for this year’s Defcon, and like most independent badges it’s loaded up with RGB LEDs, microcontrollers, and exquisitely crafted FR4. What makes this badge different is the add-ons, or ‘blocks’ that attach to the main badge through 1/8″ phono jacks. These blocks form the basis of the social game, where two badge holders trade blocks for a while, allow their badges to perform a proof of work on each block, and finally, each block is hashed and the score increased. Yes, this is a blockchain, but it’s more of a block-tree, and it runs on sneakernet instead of the Internet.

Yes, this does indeed all sound like a joke. Make no mistake, though: this is real. This is a hardware game built on blockchain technology, that some lucky badge holders will be playing at this year’s Defcon. It’s filled with blinky and blockchain. It’s awesome.

[Mr. Blinky Bling] has already started a project for this badge over on hackaday.io, and right now they’re running a Kickstarter campaign for this badge with delivery at Defcon. This is one of the more interesting badges that will be floating around the con this year, and it has blockchain. This really isn’t one to miss.

ESP8266 Home Computer Hides Unexpected Gems

June 27, 2018 by Kerry Scharfglass 71 Comments

With a BASIC interpreter and free run throughout their hardware, home computers like the ZX Spectrum and Commodore 64 used to be a pervasive way to light that hacker fire. With the advent of cheap single board computers like the Raspberry Pi, devices purpose built to emulate these classic systems have become fairly commonplace. [uli] built a device in this vein called the BASIC Engine which is driven by a microcontroller and a handful of hardware peripherals. Like other examples it can be attached to a keyboard, programmed in a BASIC, play video and sound, etc. But digging into the BASIC Engine reveals that it’s similarity to other devices is only skin deep.

The current version of the BASIC Engine (“rev2”) lives in a Raspberry Pi 3 case for convenience. It has RCA connectors for NTSC or PAL video output and mono audio, plus a bank of headers to tap into GPIOs, connectors for a keyboard, and more. [uli] wanted to aim for extreme low cost so a relatively beefy board like a Raspberry Pi didn’t fit the bill, and we expect it was an enjoyable challenge. Instead its interpreter runs atop an ESP8266 but with the networking stack removed. [uli] was disheartened by how bloated even a “Hello world” program was and ripped it out, discovering that hidden beneath was a very powerful and disproportionately inexpensive general purpose microcontroller. The video is driven by a VS23S010, sold as a 1 Mbit parallel SRAM with a neat trick; it also includes a composite video controller!

The real treat here is [uli]’s history writeup of how the BASIC Engine came to be. We’d recommend brewing a cup of coffee and sitting down for a full read-through. The first version was inspired by the PlayPower project, which was repurposing clones of Nintendo’s Famicom (NES to Americans) game console to make low cost home computers, complete with keyboard and gamepad input. [uli] started out by building a custom cartridge for a particular Famicom clone that ran a BASIC interpreter but after showing it to disinterested adults the project was left fallow. Years later, [uli] was encouraged to pick up the project again, leading down a twisted rabbit hole to where we are today.

If you want to build a BASIC Engine for yourself, Gerbers and build instructions are available on the pages linked above.

Thanks for the tip [antibyte]!

Ken Shirriff Found Butterflies In His Op-Amp

June 27, 2018 by Steven Dufresne 8 Comments

In 1976, Texas Instruments came out with the TL084, a four JFET op-amp IC each with similar circuitry to Fairchild’s very popular single op-amp 741. But even though the 741 has been covered in detailed, when [Ken Shirriff] focused his microscope on a TL084, he found some very interesting things.

To avoid using acid to get at the die, he instead found a ceramic packaged TL084 and pried off the cover. The first things he saw were four stabilizing capacitors, by far the largest structures on the die and visible to the naked eye.

When he peered into his microscope he next saw butterfly shapes which turned out to be pairs of input JFETs. The wide strips are the gates and the narrower strip surrounded by each gate is the source. The drain is the narrow strip surrounding each gate. Why arrange four JFETs like this? It’s possible to have temperature gradients in the IC, one side being hotter than the other. These gradients can affect the JFET’s characteristics, unbalancing the inputs. Look closely at the way the JFETs are connected and you’ll see that the top-left one is connected to the bottom-right one, and similarly for the other two. This diagonal cross-connecting cancels out any negative effects.

[Ken’s] analysis in his article doesn’t stop there though. Not only does he talk more about these JFETs but he goes over the rest of the die too. It’s well worth the read, as is his write-up about the 741 which we’ve also covered.