The Best Laptop Gets Even Better

November 24, 2018 by Brian Benchoff 85 Comments

The ThinkPad is the greatest laptop ever created. It doesn’t come in rose gold, it comes in black. It doesn’t have a weird screen instead of an escape key. For less than half the price of a MacBook, you can have a capable laptop that will somehow fit three drives inside. It’s madness, but it’s still not the perfect tool for hacking. To get there, you’re going to need to load that thing up with an independent Linux system, and maybe a solderless breadboard. That’s what [ollie242] is doing with his ThinkPad, and the results are the perfect addition to the perfect laptop.

This build is really just a 3D printed drive caddy for the Thinkpad UltraBay, the modular standard that allows you to add a CD drive, SATA drive, or even a serial and parallel port to your laptop. [ollie242] is modeling this off the CD drive taken from a ThinkPad T420, so we’re looking at a ‘Serial Ultrabay Enhanced’ version of this standard, which is compatible with a T430, which is still the best laptop you can possibly buy.

Inside this 3D printed drive caddy is a Raspberry Pi Zero W, powered by the ThinkPad through the internal SATA connector. The Pi Zero has right-angle headers attached, giving access to the GPIO pins from the outside. Just to add a little flair, [ollie242] added an OLED display to show the IP address, the CPU load, and the memory availability of the Pi.

This is a great project, if only because no one has any use for a CD drive anymore. Since these UltraBay drives are huge, it would be a simple matter to add a much more powerful computer to the drive like the recently announced Raspberry Pi 3 Model A+. There are — or at least there should be — some interesting internal connections on that UltraBay port, and it’s not inconceivable this Raspberry Pi UltraBay could be used as a coprocessor of sorts for its host laptop.

This Bitcoin Price Tracking Traffic Light Isn’t Just A Red LED

November 22, 2018 by Brian Benchoff 10 Comments

Quick, what’s the price of Bitcoin? Is it lower today than yesterday? Are you overdrafting your Lamborghini account? What if you had an easy way to tell at a glance how much you could have made if you sold in December of last year? That’s what this Bitcoin price tracking traffic light is all about, and it’s a great use of existing electronics.

The hardware for this build is a traffic light table lamp available on Amazon for twenty bucks. Inside this traffic light, you get a PCB with three LEDs and a small microcontroller to control the LEDs. The microcontroller isn’t used in this case, instead the microcontroller is removed and a few wires are soldered up to the base of the transistors used to drive the LEDs. The other ends of these wires are attached to a trio of pins on a Raspberry Pi Zero W, giving this traffic light table lamp Linux and a connection to the Internet.

On the software side of things, we’re looking at a Docker container running a Python script that fetches the latest Bitcoin price from Coindesk and calculates the change from the previous fetch of the price of Bitcoin. This data is shuffled off to another Python script that actually changes the LEDs on the lamp.

Sure, these days a ‘bitcoin price tracking traffic light’ is as simple as connecting a red LED to a battery, and if you’re feeling extra fancy you can add a 220 Ω resistor. But this is a project that’s so well executed that we’ve got to give it a tip ‘o our hat.

Creating Black Holes: Division By Zero In Practice

November 21, 2018 by Sven Gregori 31 Comments

Dividing by zero — the fundamental no-can-do of arithmetic. It is somewhat surrounded by mystery, and is a constant source for internet humor, whether it involves exploding microcontrollers, the collapse of the universe, or crashing your own world by having Siri tell you that you have no friends.

It’s also one of the few things gcc will warn you about by default, which caused a rather vivid discussion with interesting insights when I recently wrote about compiler warnings. And if you’re running a modern operating system, it might even send you a signal that something’s gone wrong and let you handle it in your code. Dividing by zero is more than theoretical, and serves as a great introduction to signals, so let’s have a closer look at it.

Chances are, the first time you heard about division itself back in elementary school, it was taught that dividing by zero is strictly forbidden — and obviously you didn’t want your teacher call the cops on you, so you obeyed and refrained from it. But as with many other things in life, the older you get, the less restrictive they become, and dividing by zero eventually turned from forbidden into simply being impossible and yielding an undefined result.

And indeed, if a = b/0, it would mean in reverse that a×0 = b. If b itself was zero, the equation would be true for every single number there is, making it impossible to define a concrete value for a. And if b was any other value, no single value multiplied by zero could result in anything non-zero. Once we move into the realms of calculus, we will learn that infinity appears to be the answer, but that’s in the end just replacing one abstract, mind-boggling concept with another one. And it won’t answer one question: how does all this play out in a processor? Continue reading “Creating Black Holes: Division By Zero In Practice” →

It Might Be Possible To Build A Stingray With A Raspberry Pi

November 19, 2018 by Brian Benchoff 32 Comments

If there’s one thing that’s making you insecure, it’s your smartphone. Your smartphone is constantly pinging the cell towers, giving out your location and potentially leaking your private information to anyone with a radio. This is the idea behind an IMSI catcher, or Stingray in common parlance, and now you too can build one with parts you can buy off of Amazon.

The key to this hack is a software defined radio dongle, or RTL-SDR, that has been repurposed to listen in on a GSM network. Literally the only hardware required is an RTL-SDR that can be bought online for less than fifteen dollars, and you can identify the IMSI, or unique ID linked to every SIM card, in smartphones around you. The only bit of software required is a small Python script from [Oros42], freely available on GitHub.

Of course, building an IMSI catcher with a desktop is of limited utility, and using a laptop is still a bit too bulky to surreptitiously conceal in a public location. No, to really get the bang for your buck out of this, you need to do this with a small single-board computer running off a battery pack. Luckily, [Joseph Cox] over at Motherboard reports, “It is likely possible” to run this on a Raspberry-Pi. We’re guessing it’s even more than “likely” possible.

The Smaller, More Powerful Raspberry Pi 3 Model A+

November 15, 2018 by Brian Benchoff 164 Comments

It’s that time of year again, and the Raspberry Pi Foundation has some new hardware for you. This time, it’s an improved version of the Raspberry Pi Model A, bringing it the speed and power of its bigger brother, the Raspberry Pi Model 3 B+.

The Raspberry Pi Model A is the weird middle child of the Raspberry Pi lineup, or maybe it’s the Goldilocks choice. It’s not as powerful and doesn’t have the USB ports or Ethernet jack found in the latest revision of the family, the Raspberry Pi Model 3 B+, and it’s not as small or as cheap as the Raspberry Pi Zero W. If you’re running a Pi as just something that takes in power and spits out data on the GPIO pins, the Model A might be all you need.

The full specs include:

Broadcom BCM2837B0 Cortex A-53 running at 1.4GHz
512 MB of LPDDR2 SRAM
2.4 GHz and 5 GHz 802.11 b/g/n/ac wireless LAN, Bluetooth 4.2/BLE
Full size HDMI
MIPI DSI display port / CSI camera port
Stereo Output and composite video port

In short, we’re looking at a cut-down version of the Raspberry Pi Model 3 B+ released earlier this year, without an Ethernet port and only one USB port. The wireless chipset is hidden under a lovely embossed can, and until we get our hands on this new model and a pair of pliers, we’re assuming this is a CYW43455, the Cypress chipset found in the Pi 3 B+.

The price of the Raspberry Pi 3 Model A+ will be $25 USD, with availability soon at the usual retailers. Since there’s no such thing as a Pi Zero 3 yet, if you’re looking for a powerful Linux computer, with wireless, in a small form factor, you’re not going to do much better than this little guy. You could of course desolder a Pi 3 B+, but for now this is the smallest, most powerful single board computer with good software support.

New Part Day: A $6 Linux Computer You Might Be Able To Write Code For

November 12, 2018 by Brian Benchoff 81 Comments

The latest news from the world of cheap electronics is a single board computer running Linux. It costs six dollars, and you can buy it right now. You might even be able to compile code for it, too.

The C-Sky Linux development board is listed on Taobao as an ‘OrangePi NanoPi Raspberry Pi Linux Development Board” and despite some flagrant misappropriation of trademarks, this is indeed a computer running Linux, available for seven American dollars.

This board is based on a NationalChip GX6605S SoC, a unique chip with an ISA that isn’t ARM, x86, RISC-V, MIPS, or anything else that would be considered normal. The chip itself was designed for set-top boxes, but there are a surprising number of build tools that include buildroot, GCC and support for qemu. The company behind this chip is maintaining a kernel, and support for this chip has been added to the mainline kernel. Yes, unlike many other single board computers out there, you might actually be able to compile something for this chip.

The features for this board include 64 MB of DDR2 RAM, HDMI out (with a 1280 x 720 framebuffer, upscaled to 1080p, most likely), and a CPU running at just about 600 MHz. There are a few buttons connected to the GPIO pins, two USB host ports, a USB-TTL port for a serial console, and a few more pins for additional GPIOs. There does not appear to be any networking, and we have no idea what the onboard storage is.

If you want a challenge to get something compiled, this is the chip for you.

Raspberry Pi PoE Redux

November 9, 2018 by Jonathan Bennett 19 Comments

[Martin Rowan] was lucky enough to get his hands on the revised Power Over Ethernet (PoE) hat for the Raspberry Pi. Lucky for us, he wrote it up for our benefit, including inspection of the new hat, it’s circuit, and electrical testing to compare to the original hardware.

You may remember the original release of the PoE hat for the Raspberry Pi, as well as the subsequent recall due to over-current issues. In testing the revised board, [Martin] powered a test load off the USB ports, and pulled over an amp — The first iteration of the PoE hat would often trip the over-current protection at 300 milliamps.

This afternoon, the redesigned PoE board was officially released, and the post mortem of the problem documented in a blog post. It’s a lesson in the hidden complexity of hardware design, as well as a cautionary tale about the importance of thorough testing, even when the product is late and the pressure is on.

The PoE hat converts 48 volt power down to a 5 volt supply for the Pi using a flyback transformer. The problem was that this transformer setup doesn’t deliver clean steady 5 volt power, but instead provides power as a series of spikes. While these spikes were theoretically in spec for powering the Pi and usb devices, some Raspberry Pis were detecting those spikes as too much current pushed through the USB ports. The official solution essentially consists of better power filtering between the hat and the Pi, flattening that power draw.

We’re looking forward to getting our hands on this new and improved PoE Hat, and using it in many project to come.