How To Debug A Faulty Memory Board

August 9, 2013 by Mathieu Stephan 14 Comments

While this is not exactly a hack or a fail, it definitely is an inspiring example on how to debug a faulty card.

[Quinn] is one of the very few hobbyists out there that designed her own 6502 based computer. For the young readers of Hackaday, the MOS 6502 was introduced in 1975 and has been used in the Aple // line, the Commodore 64, the Vic-20, the Atari computers, the Nintendo Enterntainment System and others.

[Quinn]’s homemade new RAM board had been working for many weeks until it started to show some weaknesses by only sporadically passing the boot RAM test. Assuming the RAM was the problem, she started by making a more advanced memory test, which showed errors at random addresses.

She didn’t have any more of the same memory chips on hand which could be used with a fresh PCB. Determined to power through the issue, she etched a new board with a new memory design. Unfortunately it also gave memory errors at boot. Only one culprit was left, which is shown in the picture above. It’s a small sizing error in the board artwork which was just enough to cause a misalignment on the connector.

The article contains many details about her debugging process, so it definitely is worth the read.

How To Use The Kenetis KL25Z Freedom Board As An HID Mouse

August 7, 2013 by Mike Szczys 12 Comments

[Eric] is interested in turning this Freedom development board into an air mouse by using the onboard accelerometer. But he had to work through the particulars of the USB HID mouse class before he could get that done.

This Freescale FRDM-KL25Z is one of the awesome ARM boards we looked at a year ago. Can you believe you can get this thing for like thirteen bucks? We suppose the gotcha is that the CodeWarrior IDE meant for use with them is not entirely free. But there is a free trial, and [Eric] shows how much easier it is to tailor the USB stack for your needs with it.

Don’t worry though. If you’re like us and use Open Source For The Win he’s got you covered as well. When you’re done reading his HID mouse writeup head on over to his six-part tutorial for building a free toolchain for the Kenetis boards.

Building A Hard Drive Scratch Controller

August 2, 2013 by Mike Szczys 12 Comments

hard-disk-scratch-controller

If you’re reading this blog then chances are you have a dead hard drive hanging out somewhere in your house. Here’s a weekend project that will put it back into use. [Andreas] took on the popular project which combines a hard drive and optical mouse to build a scratch controller.

The gist of the build is that you use an optical mouse sensor to track the movement of the platter. But [Andreas] made things harder on himself by not using the USB capability of the mouse and mapping it in software for his needs. Instead he plucked the sensor from the mouse, reading it using an Arduino. After much trial and error with the best way to coat the underside of the platter to play nicely with the sensor he managed to get it up and running. The controller issues commands using the MIDI protocol, forming a strong foundation for future upgrades which could lead to a full-blown DJ console hack.

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Disney Prototype Adds Haptic Feedback To Gestural Interface

July 29, 2013 by Mike Szczys 11 Comments

disney-haptic-feedback

This little device is about the size of a webcam, and it perches on top of your computer monitor in much the same way. It’s Disney’s solution to haptic feedback for gestural input. That is to say, wave your hands in the air to control a computer, and this will give you some sense of actually touching the virtual objects.

The thing shoots toroids of air at the user. We thought the best example of how this is used is the soccer ball demo in the video. A game is being played where virtual soccer balls are launched toward the user. The rig shoots out a puff of air to go along with each ball. When you get your hand in the right place you’ll feel the vortex of air and know you’ve made contact with the virtual object.

On the hardware side this is just begging to be recreated in your basement. What we have here is a 3D printed enclosure that has six sides. Five of them have speaker elements that create pressure waves when given an electrical signal. When coordinated they cause a perfect ring vortex (think cigar smoke ring) to shoot out the flexible nozzle which can be aimed thanks to a gimbal setup. Of course the element that makes it interactive is a 3D camera, which could be a Kinect or Leap Motion when built in the home workshop.

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LED Module Used To Display Load, Traffic, And Status Data For Your PC

July 20, 2013 by Mike Szczys 7 Comments

cpu-monitoring-block

You’re going to like [Ivan’s] write-up for this LED computer status monitor. Of course he didn’t just show-and-tell the final product — if he had you’d be reading this in a Links post. But he also didn’t just detail how he put the thing together. Nope, he shared pictures and details of every iteration that got him here.

It started off with a tachometer. Yeah, that analog display you put on the dashboard of your car which reads out RPM. He wanted to make it into a USB device which would read out his CPU load. But that’s an awful lot of work when it can only display one thing at a time. So he decided to add an 8×8 LED module which would display the load for each individual core of his CPU. It looks great next to the illuminated tachometer. From there he added resolution by transitioning to an RGB module, which ended up sucking him into a coding project to extend the data pushed to his embedded hardware. In the end his ReCoMonB (Real Computer Monitoring Block) displays CPU load, RAM usage, several aspects of HDD activity, as well as the network up and down traffic.

We think he’s probably squeezed all that he can from this little display. Time to upgrade to a TFT LCD.

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A Custom Starcraft Keyboard

July 5, 2013 by Brian Benchoff 6 Comments

keybaord

What do you do if you’re looking for a project, but don’t know what to do? If you’re [gltovar], just look around at your hobbies. He’s been playing Starcraft for a while and finally decided to build a custom Starcraft keyboard.

[gltovar] came across an interesting keyboard layout known as TheCore. Ostensibly, this layout allows the player faster access to the commands most used when playing Starcraft. [gltovar] decided he needed a keyboard specifically designed for TheCore, and set about making one of his own design.

The keyboard matrix is designed around a 1×5 row of keys, each attached to a Teensy microcontroller acting as a USB device. Each of these rows are a separate circuit board, allowing [gltovar] to move the rows up and down ergonomically in a custom enclosure.

It’s everything [gltovar] wanted in a custom keyboard. Whether it improves his Starcraft game is another story entirely, but we’re sure he’s at least having fun.

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USB Sniffing With The BeagleBoard-xM

July 2, 2013 by Mike Szczys 21 Comments

[Matlo] wrote in to share his USB sniffing project using the BeagleBoard-xM. It builds on the Google Summer of Code project from 2010 that used the non-xM version of the hardware to build a pass through USB sniffer. [Matlo] couldn’t get it to work back then, but recently revisited the project. He’s cleaned up some scripts and generally made it a bit easier for others to pull off as well.

The ARM-based BeagleBoard seen above acts as man-in-the-middle. You connect your target USB device to the board and the board to a computer. The board emulates the target device, passing packets in either direction while also logging them. The captured data is in the correct format for display using WireShark, the de facto standard for making sense of captured communication packets.

This is great for figuring out how to use USB devices on non-standard systems, or vice versa.