Interfacing With An Analog Joystick

February 6, 2010 by Mike Szczys 12 Comments

[Firestorm_x1] put together a tutorial about interfacing an analog joystick with a microcontroller. These analog sticks are easy to find; he got his from Goodwill but we’ve got a couple in our junk box right now. The stick uses variable resistors to report its position so it’s just a matter of reading and interpreting that data. After explaining the concepts he demonstrates how to use the joystick to control a Basic Stamp 2 based robot, the Boe-Bot. This could easily be adapted for use with other robot platforms.

Update: Adafruit Eagle Library, Now With Arduino

February 6, 2010 by Mike Szczys 9 Comments

Adafruit Industries has just added an Arduino shield footprint to their EagleCAD library. If you don’t know, the Arduino headers use non-standard pin spacing. Learn to deal with it, there’s too many Arduino shields in production to have any hope for a change in the future. This footprint should make it a lot easier to design your own boards. If you use this package make sure you’re getting the library from their github, they’ve been adding parts regularly. Setting up version control will make sure you always have the latest libraries.

[Thanks pt]

Hardware Based Randomness For Linux

February 6, 2010 by Mike Szczys 28 Comments

True randomness can be hard to come by in the digital world. [Andy Green] is making it easier to get true entropy by using this random USB dongle. The Whirlygig uses a CPDL to gather data from a set of of oscillators. The oscillators have a constantly fluctuating frequency due to temperature changes; if they run faster they generate more heat which in turn slows them down. This, along with the variable latency associated with polling a USB device, gives great depth of randomness. The device is detected and mounted under ‘/dev/hw_random’ and can then be fed into ‘/dev/random’ using the rng-tools package. [Andy’s] done a lot of testing, both on the hardware, and on the quality of randomness. We didn’t see an option to order this but he’s got hardware and firmware repositories so that you can throw one together yourself.

[Thanks Zunk]

Pre-spun Hard Drives

February 5, 2010 by Mike Szczys 56 Comments

This device is lovingly called the SPINmaster. [Linux-works] built it to spin up multiple hard drives before the motherboard starts up. It detects the power-up from the PSU and uses a relay to hold the motherboard in reset, indicated by the red LED. Each of four relays then spins up a hard drive and illuminates the green LED when ready. Once all green lights come on the reset relay shuts off and the bios starts up. This type of staggered startup takes a lot of the load off of an under-powered PSU. He’s posted firmware and there’s a schematic available too. We took a look at his video but there’s not much to see as it’s just the inside of the machine while it boots up.

Pipe Heating With An ATMega8

February 5, 2010 by Caleb Kraft 22 Comments

[Viktor] wanted a system to keep his pipes from freezing. The common method of using heat tape works pretty well, but can be wasteful. Many people just turn it on for the entire winter. [Viktor] wanted to automate the heat tape’s power so that it only activated during times that the pipes could actually freeze. To do this, he rigged an ATMega8 to a temp probe and is using it to control an ATX power supply. Pretty slick [Viktor].

[via HackedGadgets]

Repurposing A Click Wheel

February 5, 2010 by Mike Szczys 24 Comments

We think the click wheel is the biggest contributor to the success of the original iPods. The devices were a brick with a monochrome screen but the user interface was slick and easy to use. [Jason] decided he wanted to add a click wheel to his own project. After using a logic analyzer he discovered that it doesn’t implement a common protocol such as I2C, perhaps a deliberate move by Apple to keep the controller under wraps? He managed to get past this hurdle, as seen in the video after the break, by bit-banging the data in from the click wheel and then reverse engineering the protocol.

It’s connected to an AVR ATtiny88 with feedback shown on a character LCD screen. We’re glad that [Jason] tipped us off about this, but he doesn’t have any code available yet. We love to dive into the source so the sooner he gets it up the better! We’ve got an old 3rd generation with a bad board that is begging to have the wheel ripped out of it, not to mention the dirt-cheap replacements available on ebay. Continue reading “Repurposing A Click Wheel” →

Arduino To Nintendo DS Interface

February 5, 2010 by Mike Szczys 15 Comments

[Hounjini] was poking around at the Game Boy Advanced bus of his Nintendo DS lite and figured out how to use it to connect an Arduino to the DS. For testing he’s soldered an IDC plug to the cartridge cover pin interface but this only requires four connections. The Arduino can both send and receive data from the DS lite as shown in the example videos after the break. The data access is made possible by making the Arduino look like a controller that the DS is happy to talk to.

Continue reading “Arduino To Nintendo DS Interface” →