[Mirko] is working on a library that will allow you to add RF control to just about any device. The only requirement is that the device be capable of running a Linux kernel, and that it have a few GPIO pins available. One example is fairly straight forward, a Netgear router. Many, if not most routers run a Linux kernel natively and most have solder points on the board for unused IO pins so patching into the hardware is very straight forward. Less obvious and much more impressive is the hack seen in the image above. [Mirko] built an SD card adapter cable and uses the contacts in the card reader to bit bang four-wire SPI to communicate with that RF module.

Bug Labs makes hardware modules that can be combined to create your own custom gadgets. They’ve just released what we consider the most useful module: BUGvonHippel. Unlike the previous single purpose modules, the BUGvoHippel is a universal interface. The bus features USB, power/ground, DAC/ADC, I2C, GPIO, SPI, serial, and more. BUG applications are written in Java using a custom IDE.

The $79 module is named after MIT professor Eric von Hippel, who wrote Democratizing Innovation. You can find an interview with him below.

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SparkFun’s latest tutorial shows you how to work with relays. A relay is an electrically operated switch. In this case, they’re using it to switch a 120V AC outlet. The article carries the standard warnings about how not to kill yourself with AC (plus some non sequitor linking throughout). As an extra precaution, they chose a GFI outlet. You probably know how a relay works, but it’s worth seeing how they implemented it. They use a transistor to prevent overloading the microcontroller’s GPIO pin. The control pin is pulled to ground to keep the relay off. A diode is placed across the relay coil to manage the power flow when it discharges. An indicator LED is included to show when the relay closes. This is a great foundation for an automation project, or maybe you just want to terrorize your cat.

Yesterday, we featured [Andrew]‘s orientation aware camera. We want to highlight another one of his projects: LED Life. It’s a 6×5 LED matrix playing Conway’s Game of Life. He used the low power MSP430 like our e-paper clock. The best part of the writeup is his explanation of how Charlieplexing works. Microcontroller GPIO pins generally have three possible states: output high, output low, and input. This combined with the directional nature LEDs and some creative wiring means you can run a large matrix of individually addressable LEDs with just a few IO pins. Instead of just flipping the IO pins on and off you change their assigned state. Have a look at [Andrew]‘s site for some great illustrations of how the system works. A video of his LED Life board is embedded below. Read the rest of this entry »