Help Save Nullspace Labs

Nullspace Labs

A few days ago, the folks at Nullspace Labs in downtown LA got a surprising memo: their building is going to be gutted in a month. With thirty days left, they need money to cover first and last months rent, and help with moving. We can imagine that moving a Hackerspace is no small feat, since they tend to accumulate tons of awesome stuff.

The Hackerspace has started a crowd funding campaign, and has posted a call for help. They are looking for money, new members, or help with moving. If you’ve never been, you can check out our tour of Nullspace Labs.

It’s tough deciding what Hackerspace news to cover. We can’t run individual features on every tip we get promoting Hackerspace events, developments, crowd funding campaigns, and calls for help. We’re featuring this one because we just visited them, they’re awesome, and they’ve also been the source for many great stories over the years, like craning in a laser cutter or developing a modular LED orb. So here’s a question for you: Should we be presenting more Hackerspace news that is perhaps only relevant at the local level? If you think we should, how would we present it? There’s the option of doing occasional links-post-like roundups. But if you have a better idea we’re all ears.

Reverse Engineering an HDMI Extender

reverse-engineer-hdmi-extender

There’s a number of devices out there that extend HDMI over IP. You connect a video source to the transmitter, a display to the receiver, and link the two with a CAT5/5e/6 cable. These cables are much cheaper than HDMI cables, and can run longer distances.

[Daniel] didn’t care about extending HDMI, instead he wanted a low cost HDMI input for his PC. Capture cards are a bit expensive, so he decided to reverse engineer an IP HDMI extender.

After connecting a DVD player and TV, he fired up Wireshark and started sniffing the packets. The device was using IP multicast on two ports. One of these ports had a high bitrate, and contained JPEG headers. It looked like the video stream was raw MJPEG data.

The next step was to write a listener that could sniff the packets and spit the data into a JPEG file. After dealing with some quirks, JPEG images could be saved from the remote device. Some more code was needed to have the computer initiate the streaming, and to extract audio from the second port.

In the end, video capture with the low cost device was possible. [Daniel] also provided a bonus teardown of the device in his writeup.

A Meccano Pinball Machine

Meccano Pinball

This pinball table is almost entirely out of Meccano Construction Set parts. [Brian Leach]‘s Meccano Pinball Machine features a digit counter, a kick out hole, flippers, and a timer.

The digit counter is likely the most complex part of the build. By sending it an electrical signal, either the ones, tens, or hundreds digit can be incremented. The electrical signal engages an electromagnet, which connects a motor to the wheel to increment the score. A mechanism ensures the next digit is incremented when a digit rolls over from 9 to 0, and allows the counter to be zeroed.

Rolling the ball over the set of rollover switches increments the score. A mechanism is used to ensure that the switch will trigger with a small weight. Arcing was an issue, which was reduced by adding a snubber to suppress the transient.

The pinball machine was demoed at the South East London Meccano Club, and is a great demonstration of what can be built with the construction kit. After the break, check out a video of the pinball machine.

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Microcorruption Embedded CTF

Microcorruption Debugger

The folks at Matasano Security and Square have teamed up to build an online capture the flag (CTF) competition. The Microcorruption CTF focuses on embedded security and challenges players to reverse engineer a fictional “Lockitall LockIT Pro” lock system.

Each level places you in a debugging environment with a disassembly listing, live memory view, register view, and debugging console. You can set breakpoints, step through code, and modify registers like in a real debugging environment. Your goal is to figure out how to bypass the lock to collect bearer bonds.

While the device and motive may be fictional, the assembly is actual MSP430 code. The debugger is similar to GDB connected to a remote target using OpenOCD. There’s even a manual (PDF) to help you get up to speed with writing MSP430 code for the device.

This CTF looks like a great introduction to embedded security, and doesn’t require buying real hardware. It even includes a full tutorial to get you started.

Sega Master System on a STM32 Development Board

Sega on STM32

Some hackers have managed to convert an STM32 development into a Sega Master System emulator. This means Sonic the Hedgehog running on an ARM Cortex-M4.

This hack has a number of parts. First, [Alessandro Rocchegiani] showed off a video of his Sega Master System emulator running on the STM32F429 Discovery development board. This first version used the on board 2.4″ TFT LCD screen.

[Fabrice] was working with this STM32 Discovery board already. He had developed an expansion board that added a number of features to the development kit, including an R-2R DAC for video output. When [Fabrice] found out about the Sega Master System emulator, he worked with [Alessandro] and his son [Fabrizio] to get VGA output working. They also added support for the Wii controller using [Fabrice]‘s Wii library. The result is a Sega Master System emulator with VGA output at 640 x 480, with 16 bit color and Wii controller support.

You can watch a video of both the LCD and VGA versions of the hack after the break.

[Read more...]

An Arduino Library for the PS4

PS4 Controller

Looking to interface your Arduino with the PS4 controller? [Kristian] has updated his USB host library with support for the controller. The library makes it easy to read most of the inputs from the controller. Currently the buttons and joysticks work, and support for the light sensor, rumble, and touchpad is on the way.

To get this working, you will need the USB Host Shield for the Arduino and a Bluetooth dongle. Once you have the hardware setup, you can use the library to pair with the controller. When connected, simple function calls will let you read the state of the device.

While this does require some additional hardware to connect, all of the code is open source. If you’re looking to experiment with the PS4 controller yourself, [Kristian]‘s work could be a helpful starting point. Of course, all of the source is available on Github, and the example sketch shows how easy it is to roll the PS4 controller into your own Arduino project.

Software Half Duplex UART for AVRs

One Wire Serial

If you have worked with very low cost microcontroller in the past, such as the ATtiny series from AVR, you’ve probably been stuck without a UART peripheral. The usual answer to this problem is to implement the UART in software. It’s not fast, but it works.

Lets say you’re even more limited on resources, and only have a single pin for UART. [Ralph] created a software library and a small circuit that enables half duplex UART using only one pin. With the above circuit, and a 62 byte Arduino compatible library, you can add UART to the tiniest of ATtinys.

In this circuit, the Tx/Rx pin is on the AVR, and the Tx and Rx pins are another device. The circuit relies on the idle state of UART being a logic high signal. When the Tx pin is idle, the transistor stays on. This allows the Tx/Rx pin to pull Rx low when the AVR sends a 0. When the Tx pin sends a 0, the Tx/Rx pin gets pulled low through the diode.

It’s a clever hack, and could definitely help add communication to your next tiny project.