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www.pabr.org publishes DIY projects and other educational resources in various fields of science and technology.

Toward thermoelectric production of dry ice ? (2016-09-18)

In this project I try to make dry ice by cooling carbon dioxide to -80°C with Peltier modules.
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HAMPADS: HAM-Portable Affordable Dish for Satellites (2016-03-20)

A shoulder-mounted dish, tracking system and SDR receiver for amateur radio communications, originally designed for receiving HamTV digital video transmissions from the International Space Station.
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leandvb: A lightweight software DVB-S demodulator (2016-02-19)

leandvb is a lightweight implementation of portions of the DVB-S standard in plain C++. It is developed primarily for receiving Digital Amateur TV, including HamTV from the International Space Station.
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SDR reception of Digital Amateur TV from the ISS (2015-10-13)

How to receive DVB-S digital video transmissions from the International Space Station with a bit of hardware and a lot of software.
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Toward mobile Linux devices with auditable security (2015-09-23)

This web page documents my attempts to assemble Linux smartphones and tablets with as few non-mainstream components, binary blobs and potential backdoors as possible. Currently the best candidate is a Lenovo Yoga Tablet 2 851 running Fedora 22.
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A better audio jack console cable for Google Nexus devices (2015-09-04)

Many Google Nexus smartphones and tablets have a serial console which can be accessed through the headset socket. This is an invaluable tool for software development. Unfortunately there are no suitable off-the-shelf adapters on the market; therefore some tinkering is required.
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First-person view and remote control with LEGO Mindstorms EV3 (2014-12-14)

We add FPV and RC functionality to a LEGO Mindstorms EV3 vehicle with a PlayStation gamepad, USB webcams, a smartphone-based stereoscopic head-mounted display, and the alternative operating system ev3dev.
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Seeing the world through a depth-sensing camera (2014-11-10)

In this project we attach a depth-sensing camera to a head-mounted stereoscopic display (think: Kinect + Google Cardboard). The resulting portable device allows users to see their surroundings in unusual ways.
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brickhid - Direct connection between Bluetooth gamepads and LEGO Mindstorms EV3 (2014-10-24)

We show how to interface LEGO Mindstorms EV3 directly with off-the-shelf Bluetooth gamepads and joysticks such as the PS3 SIXAXIS and DualShock 3 controllers.
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Bitcoin's centralized endgame, and how to avoid it (2014-09-03)

We review 19 common misconceptions about the Bitcoin crypto-currency system and show how the reality helps predict its endgame: centralized mining, then centralized governance. We suggest that enforcing national mining quotas might be the lesser of many evils if centralization is to be avoided. More generally, we introduce the idea of maximally-distrustful oligopolies as a practical solution to distributed consensus.
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The science of garden swimming pools (2014-06-29)

How an engineer looks at kiddie pools: tensile strength of curved walls, thermal conductivity, evaporative cooling, blackbody radiation, Sun ephemerides, and water sanitation techniques.
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A taxonomy of Heartbleed attacks (2014-04-16)

One week after the disclosure of the Heartbleed vulnerability, security experts are still discovering new ways it could affect online security. This document attempts to classify attack patterns and their countermeasures as they emerge. It will help you understand whether you really need to change your passwords, why it was unwise to do it too early, and why you should know whether your browser detects revoked certificates.
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RSSKISS: A RSS feed reader in 100 lines of code (2014-04-12)

rsskiss is a quick-and-dirty replacement for Google Reader.
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Interesting factoids in science and technology (2014-01-22)

A collection of little-known, counter-intuitive or otherwise enlightening facts in various fields of science and technology.
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Load-testing generators with Gray codes (2012-10-01)

Digital circuit theory meets gasoline engines as we design a monotonically-adjustable, low-component-count dummy load suitable for testing electric generators in the kilowatt range.
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Homodyne measurement of Earth's rotation with a motion-sensing videogame controller and a record player (2011-02-10)

Got a PlayStation Move and an old vinyl turntable ? You can try to detect Earth's rotation, find geographic north, and determine your latitude.
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linmctool - Linux motion-sensing controller tool (2010-11-17)

linmctool provides minimal support for popular Bluetooth motion-sensing game controllers on Linux: PlayStation Motion Controller (PS Move), Sixaxis, DualShock3, Wii Remote (Wiimote).
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WXHMD - A Wireless Head-Mounted Display with embedded Linux (2009-09-01)

WXHMD is a Gumstix Overo Fire computer-on-module driving a Vuzix VR920 head-mounted display: Stereoscopic 640x480, audio in/out, 3D tilt sensor, 3D magnetic compass, TI OMAP3530 @ 600 MHz, Linux, WiFi, Bluetooth, 1 amp @ 3.7 volts, 180 grams. Potential applications include secure telepresence over WiFi, and "head-mounted computing" with Bluetooth peripherals.
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pcbprt - Experiments in inkjet PCB printing (2009-09-01)

For the last few years hobbyists worldwide have been experimenting with inkjet PCB printing, i.e. manufacturing electronic circuit boards with inkjet printers. This is a report on my experience with this technique.
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Home server form factor for 600x300 mm ETSI racks (2008-04-29)

I argue that manufacturers of home servers and NAS appliances should standardize on the half-depth ETSI subrack form-factor and cabling conventions: 19" mounting plate, 240 mm deep, all connectors on the front panel.
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Using the PlayStation 3 controller in Bluetooth mode with Linux (2007-04-23)


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pxaRC - R/C and robotics software for Linux/PXA255/PXA270 (2005-06-02)

pxaRC is a collection of drivers and utilities for remote-control and robotics applications on Linux/PXA255/PXA270-based platforms such as the Gumstix basix, connex and verdex motherboards.
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CFcam - Connecting a CMOS camera to a Gumstix Connex motherboard (2006-09-12)

This document explains how to connect a digital CMOS image sensor directly to the CompactFlash port of a Gumstix Connex computer (or similar PXA255-based platform).
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ChRoMicro - Cheap Robotic Microhelicopter HOWTO (EN) (2005-06-02)

RC model helicopter prices have reached a point where all sorts of challenging (i.e. crash-prone) robotics projects become affordable. This document explains how to build a 300 g helicopter with embedded Linux and Bluetooth datalink from off-the shelf components for less than 500 EUR.
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