How To Fix AVR-SIZE On Ubuntu 10.04

The program avr-size is part of the AVR-GCC toolchain used to develop programs for that line of microprocessors. The program tells you how much space the code will take up on the chip, important information if you’re trying to cram a program into a small program memory. Perhaps more importantly, it shows you how much ram is being used. This is the “Data:” portion of the image above and if you overflow the memory this will be the only thing that lets you know that has happened (except for unstable behavior once the program is running).

For quite some time the avr-size package in Ubuntu has been missing a key feature that makes the information more human readable. [Jeff] over at mightyohm tracked down the solution to the problem on the bug tracker and posted the directions on how to bring your copy up to date. Basically, download the package from Debian (an upstream copy that has already been patched) and install it. [Jeff’s] guide is based on the AMD64 version so we’ve copied his procedure in a more generalized fashion after the break.

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Using Quality Optics With A Webcam

[Devon Croy] built a case to join a webcam sensor with a camera lens. The box is a PVC conduit box you’d find at a home center. He used JB Weld to attach four bolts to the back of the box. These are used to fine-tune the mounting plate for the webcam sensor to ensure it’s at the focal point of the lens. The lens connects through a couple of extension tubes to an adapter mounted in the center of the box’s cover plate. The setup above shows a macro lens that takes pretty good pictures.

If you need images of really tiny things you should look into a microscope adapter for your camera.

Open Source Version Of The Play Station 3 Jailbreak

Don’t steal. It’s a lesson that children are taught from the youngest age and a core principle in every society. The PSGroove sets out to follow this mantra in several ways. It is an open source implementation of the PSJailbreak hardware we covered a couple of weeks back. It’s difficult to find a definitive source of information on that hardware but many have speculated that the original device contains stolen code. Whether that’s true or not is moot as the PSGroove doesn’t include the backup manager program alleged to violate copyright.

The device is also aimed at running homebrew, and doesn’t natively allow one to play backups. It runs on a variety of AVR hardware, including the Teensy boards. If you have one of them, it’s just a matter of compiling the code and unlocking the potential of your PlayStation 3.

[Thanks Mark via PS3news]

Replacing The Driver Board In An Old-school Door Chime

[Dan Kouba’s] parents replaced their doorbell button with one that lights up and found that the chime wouldn’t stop sounding after the button was pushed. These lighted buttons use an incandescent bulb in parallel with the button (a piece of hardware we’ve hacked in the past). It draws a small amount of current which isn’t enough to trigger the chime, but it is just enough that the chime unit reacts as if the button press never stopped. His parents asked what he could do about this and after some investigation he build a replacement board for the chime unit based around an ATtiny26L. The board monitors the voltage drop across a resistor in the doorbell circuit. When the comparator on the AVR detects a rise in the voltage drop across the resistor it rings the chimes, actuating the solenoids with a set of PNP transistors. [Dan] sent us all of the details which you can check out after the break.

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Making A Smaller Keyboard

The keyboard on [Marek’s] laptop stopped working. He didn’t want to buy a replacement so he decided to start using an external keyboard. But hauling around a full 104-key model is a bit of a pain so he decided to make himself a shorter keyboard. He basically chopped off the 10-key pad on the right side of the board. This had the unexpected consequence of removing the screws that hold the top and bottom of the case together so he ended up adding a few extra screws to shore it up. You may be wondering how the key matrix still works if a portion of it has been cut off. [Marek] used the simple trick of folding the extra part of the membrane over and covering the unused contacts with some tape.

If you try this you should consider getting rid of the directional arrows and editing keys as well. There must be a way to map those keys elsewhere. Perhaps the half-qwerty keyboard hack will give you some inspiration for that.

Wearable Controller For Your Paintball Tank

If you’re too frail to take the full impact of a paintball round let this tank serve as your surrogate. The camera perched on top of the platform feeds video back to the operator’s head-mounted display. Instead of using a joystick or other traditional controller, the user aims by looking around, with his or her head movements mimicked by the camera and barrel of the tank. It looks cooler than it sounds so jump with us after the break to see for yourself. If you’re playing against this thing, we’d recommend aiming for the camera lens.

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Build Your Own Magnetic Levitator

Here’s a great magnetic levitator build. [Scott Harden] dug up the link after seeing that awesome rotating globe this morning. This version hangs objects below an electromagnet but it has a sensor system to provide a constant distance between magnet and object even if the payloads are a different weight. This is done with a couple of infrared sensors. One acts as a reference detector, always viewing an IR LED in order to get a baseline measurement. That measurement is compared to a second detector mounted slightly lower. The circuit adjusts the electromagnetic field, making sure the object is always breaking the lower beam but never interrupting the reference beam. No microcontroller needed, this is handled with a couple of OpAmps. See it in action after the break.

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