This NES ROM is a ZIP of its Source

Polyglots, in computing terms, are files have multiple valid meanings. We’ve seen some amazing examples of polyglot files in releases of The International Journal of PoC||GTFO. One example: a PDF that is also a ZIP, HTML file, and BPG image.

[Vi Grey] was inspired by PoC||GTFO’s release of a PDF/ZIP/NES ROM hybrid file for issue 0x14. Using a different method, [Vi] created a file which is both an NES ROM and ZIP, where the full contents of the ZIP are stored in the NES ROM.

When PoC||GTFO created their NES ROM polyglot, they stuck most the information outside the bounds of the NES ROM. While the file is valid, you’d lose the ZIP archive if it was burnt to a cartridge.

[Vi]’s polyglot is different. Rip it from a real NES cartridge and you get a ZIP file. Unzip it, and you get the source. Compile that source, and you get a valid ZIP file containing the source. Burn that to a cartridge and… hopefully you grok the recursion at this point.

The source and scripts to mangle the polyglot together are up on Github.

Tomu: A Microcontroller for Your USB Port

Looking for a ultra tiny development board? Tomu is an ARM Cortex M0+ device that fits inside your USB port. We’ve seen these in person, and they’re tiny.

There’s a few commercial devices in this form factor on the market. For example, the Yubikey Nano emulates a keyboard to provide codes for two-factor authentication. The Yubikey’s tiny hardware does this job well, but the closed-source device isn’t something you can modify.

Tomu is a new device for your USB port. It sports a Silicon Labs EFM32 microcontroller, two buttons, and two LEDs. This particular microcontroller is well suited to the task. It can talk USB without a crystal for timing, and has an internal regulator to generate the core voltage from a 5 V USB supply. Since it supports DFU firmware updates, it can be reprogrammed without any special tools.

Unfortunately, the EFM32 device lacks secure storage options, so the Tomu might not be the best device to keep your secrets on. That being said, it will be interesting to see what applications people come up with. The creators have suggested using the device for media buttons, sleeping and waking a computer, and as a U2F key.

The project is currently available on CrowdSupply, and all design files and source is available on their Github. If you like soldering tiny things, the twelve-part bill of materials should be fairly easy to assemble at home.

A Fully Featured, Fifty Dollar QRP Radio

QRP radio operators try to get maximum range out of minimal power. This term comes from the QRP Q-code, which means “reduce power.” For years, people have built some very low-cost radios for this purpose. Perhaps the best known QRP kit is the Pixie, which can be found for less than $3 on eBay.

The QCX is a new DIY QRP radio kit from QRP Labs. Unlike the Pixie, it has a long list of features. The QCX operates on the 80, 60, 40, 30, 20, or 17 meter bands at up to 5W output power. The display provides tuning information, an S-meter, and a CW decoder. An on-board microswitch functions as a basic Morse key, and external Iambic or straight keys are also supported. An optional GPS can be used as a frequency reference.

The radio is based around the Silicon Labs Si5351A Clock Generator, a PLL chip with three clock outputs ranging from 2.5 kHz to 200 MHz. The system is controlled by an Atmel ATmega328P.

Demand for the kit has been quite high, and unfortunately you’ll have to wait for one. However, you can put down your $49 and learn Morse code while waiting for it to ship. While the project does not appear to be open source, the assembly instructions [PDF warning] provide a full schematic.

DIY USB Power Bank

USB power banks give your phone some extra juice on the go. You can find them in all shapes and sizes from various retailers, but why not build your own?

[Kim] has a walkthrough on how to do just that. This DIY USB Power Bank packs 18650 battery cells and a power management board into a 3D printed case. The four cells provide 16,000 mAh, which should give you a few charges. The end product looks pretty good, and comes in a bit cheaper than buying a power bank of similar capacity.

The power management hardware being used here appears to be a generic part used in many power bank designs. It performs the necessary voltage conversions and manages charge and discharge to avoid damaging the cells. A small display shows the state of the battery pack.

You might prefer to buy a power bank off the shelf, but this design could be perfect solution for adding batteries to other projects. With a few cells and this management board, you have a stable 5 V output with USB charging. The 2.1 A output should be enough to power most boards, including Raspberry Pis. While we’ve seen other DIY Raspberry Pi power banks in the past, this board gets the job done for $3.


Hackaday Prize Entry: Modular Stepper Control

Stepper motors are a great solution for accurate motion control. You’ll see them on many 3D printer designs since they can precisely move each axis. Steppers find uses in many robotics projects since they provide high torque at low speeds.

Since steppers are used commonly used for multi-axis control systems, it’s nice to be able to wire multiple motors back to a single controller. We’ve seen a few stepper control modules in the past that take care of the control details and accept commands over SPI, I2C, and UART. The AnanasStepper 2.0 is a new stepper controller that uses CAN bus for communication, and an entry into the 2017 Hackaday Prize.

A CAN bus has some benefits in this application. Multiple motors can be connected to one controller via a single bus. At low bit rates, it can work on kilometer long busses. The wiring is simple and cheap: two wires twisted together with no shielding requirements. It’s also designed to be reliable in high noise environments such as cars and trucks.

The project aims to implement an API that will allow control from many types of controllers including Arduino, Linux CNC, several 3D printer controllers, and desktop operating systems. With a few AnanasSteppers one of these controllers, you’d be all set up for moving things on multiple axes.

First Look: Macchina M2

In the past few years, we’ve seen a growth in car hacking. Newer tools are being released, which makes it faster and cheaper to get into automotive tinkering. Today we’re taking a first look at the M2, a new device from the folks at Macchina.

The Macchina M1 was the first release of a hacker friendly automotive device from the company. This was an Arduino compatible board, which kept the Arduino form factor but added interface hardware for the protocols most commonly found in cars. This allowed for anyone familiar with Arduino to start tinkering with cars in a familiar fashion. The form factor was convenient for adding standard shields, but was a bit large for using as a device connected to the industry standard OBD-II connector under the dash.

The Macchina M2 is a redesign that crams the M1’s feature set into a smaller form factor, modularizes the design, and adds some new features. With their Kickstarter launching today, they sent us a developer kit to review. Here’s our first look at the device.

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Turn Your New Years Resolution Into a Belt Grinder

We’re just over a month into the new year, and some people’s resolve on those exercise plans are already dwindling. There’s some good news though. That treadmill can be hacked into a nice belt grinder for your shop.

[Bob]’s treadmill belt grinder is based on a 2.5 horsepower motor he salvaged from a broken, donated treadmill. This motor needs 130 VDC to run, which is a bit of a challenge to generate. Fortunately, lots of treadmills seem to use the same MC-60 motor controller, which is compatible with this motor. Due to the widespread use of this controller, they can be found on eBay for about $30.

With the motor spinning, [Bob] built up a frame for the grinder, added rollers to hold the belt, and a spring based belt tensioner. The motor’s speed set point is controlled by a potentiometer, and the controller varies the power to keep a constant speed. Since the motor is capable of some serious RPM, a tachometer was added for feedback to prevent high-speed belt shredding.

The final result is a very professional looking tool for under $200. What would a grinder like this be used for? Knives of course! 2″ belt grinders are perfect for shaping and grinding knives and swords. In fact, you can see one in use in this sword hack.

Check out a video of the build after the break.

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