HHH: CNC Storage Base From The Rabbit Hole

October 18, 2013 by 18 Comments

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Remember when we announced the Hackaday Hackerspace Henchmen program and asked you to send in the best CNC hacks from your Hackerspace? Well so far this is the only entry, which puts [Mazz] in the top spot to take all the loot for himself. Send in your projects by 10/31/13 if you want a shot at stickers, shirts, and a parts vendor gift card.

What he sent in is a storage cabinet base built for his hackerspace — The Rabbit Hole in Rochester, Minnesota. The group managed to get their hands on a CarveWright CNC machine but didn’t have a spare bench to put it on. The thought of dropping a lot of cash into something wasn’t appealing to them. But as luck would have it, about the same time this arrived at the space one of the members spied a free filing cabinet curbside.

The cabinet was a vertical four-drawer unit. It was chopped in half, with the resulting two-drawer units bolted side-by-side to each other. From here a frame was built to support the cabinets, along with locking casters so that it’s easy to move around. The inaugural run with the new machine/cabinet combination was to mill a sign for the space:

rabbit-hole-carved-sign

Making A Diode Matrix ROM

October 18, 2013 by 34 Comments

Here is a nice project that allows youngsters (but also adults!) to actually see the data stored in a Read Only Memory (ROM). The memory shown in the picture above is made of diodes. [Scott] made it as a part of his Barcamp Fall 2013 presentation about visualizing ROMs. He starts his write-up by stating the obvious: this memory is not practical. Nonetheless, it still was a fun exercise to do. [Scott] then greatly described all the different kinds of read only memories that you can find out there, with a few words explaining how they work. In his diode ROM, bits are ‘programmed’ by adding (or not) a diode between a given data line (anode) and an address line (cathode). When pulling low a given address line, the corresponding data line will only be pulled low if a diode is present. [Scott] finally checked his circuit by using a very old device programmer which could only be run in DOS.

Keyboard Spoofs 4 NES Controllers For Chiptune Goodness

October 18, 2013 by 7 Comments

NES-keyboard

This toy keyboard is being used to play music on an NES. As you probably already know, the hardware inside those original controllers was dead simple. They’re just a parallel to serial shift register that reads from all of the keys. To get this keyboard up and running [heavyw8bit] simply mounted eight chips inside the gutted toy, connecting two of them to the keyboard keys, and the rest to the array of push buttons he added to the right.

So what’s the point of using this as a quadruple game controller? Are you expecting to see what a full speed-run of Contra looks like using this as the controls? That’s not the point at all. This becomes a musician-friendly frontend for the NES synthesizer ROM called NESK-1. [heavyw8bit] wrote the game/program in order to allow you to use the original console hardware to play all of the sounds you know and love. Our favorite is the arpeggio example heard at about 2:35 into the clip after the break.

Continue reading “Keyboard Spoofs 4 NES Controllers For Chiptune Goodness” →

Laptop Keyboard EL Panel Backlight

October 17, 2013 by 26 Comments

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[nullpointr] wanted a backlit keyboard for his Asus Transformer Prime so that it would be a bit easier to use in low-light situations. He considered a few different options and ended up adding electroluminescent panels behind the keys.

Those paying close attention might wonder why we called this a laptop in the title. Well, it’s a tablet with a keyboard dock and that’s a mouthful. This actually really helps to simplify the modifications because the motherboard and other bits are all in the screen portion of the device. EL panels are also a nice choice because you can cut them to size and they still function. With a bit of case work, three panels were made to fit side-by-side.

The part that just isn’t going to make it in the original enclosure is the inverter that drives the panels. It’s the black box to the left. [nullpointr] added a USB-form-factor jack to the side of the case that allows the inverter to be disconnected quite easily. This way the Transformer Prime can still go with him on the road, it just won’t light up unless he also hauls around that add-on.

Way way back we saw someone do this with fiber optics and an LED. Unfortunately that project link seems to be dead so we figure it’s about time someone revisited the concept.

Tips And Tricks For The C Pre-processor

October 17, 2013 by 54 Comments

C Pre-processor

The C pre-processor can help you write more concise, easy to follow code. It can also let you create a tangled ball of macros and #defines. [s1axter] wrote up a guide on how to use the pre-processor and keep your sanity.

We’ve seen some neat hacks with the C pre-processor, such as a full adder implementation, but this focuses on more practical usages. First, [s1axter] explains what the pre-processor does with your code by writing simple macros. Next up is arguments, and usage of ‘##’ directive for metaprogramming. Finally, we get a good explanation of why you need to worry about scope when using macros, and how to safe code by using ‘do {} while()’ statements.

If you’re into embedded programming, this guide will help you understand some of the more complex pre-processor techniques out there. It’s helpful for making your code clearer, and abstracting away hardware dependencies in a few lines of code.

Making Use Of The Trancend WiFi SD Card

October 17, 2013 by 14 Comments

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[CNLohr] spends most of his time on the Internet, but sometimes real life drags him away from his keyboard. These “vacations”, as he calls them, don’t have a good Internet connection and forces him to rely on flaky cell phone connections that go up and down at the drop of a hat. Figuring this would be a great opportunity for some hardware hacking, [CNLohr] came up with an ‘Internet-o-mometer’ – a device powered by a Trancend WiFi SD card that uses an 8×8 LED display to show the current status of his phone’s Internet connection.

This build uses the Trancend WiFi SD card motherboard we’ve seen before. When the card boots, it tries to connect to his phone’s WiFi connection.  When it connects, a green smiley face is displayed on the LED matrix. When a whole lot of files are downloaded or, more specifically, the ping to google.com is more than 4 seconds, a red frowny face indicates the Internet connection is down.

In other Trancend WiFi SD card news, a whole lot of people including [Dan Krause] (thanks for the tip) have been working on a complete replacement OS for these neat little cards. Right now the OS is in very rough shape, but there is a pre-built system available should anyone want to experiment. [CNLohr] is also working on a compact, double-sided version of his SD card motherboard and we’ll be happy to feature a link to his Tindie store when he sends that in.

Artificial Leg Comes With A Normal Gait!

October 17, 2013 by 10 Comments

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Did you know over 50% of amputees take at least one fall per year due to limited prosthetic mobility? That compares to only about a third of all elderly people over the age of 65!

[Professor Mo Rastgaar] and his PhD student [Evandro Ficanha] set out to fix that problem, and they have come up with a microprocessor controlled prosthetic foot capable of well, to put it bluntly, walking normally.

Working with a scientist from the Mayo Clinic, the pair have created a prosthesis that uses sensors to actively adjust the ankle to create a normal stride. Commercially available prosthetics can do this as well, but can only adjust the foot in an up-down motion, which is fine — if you only plan on walking in a straight line. In addition to having an ankle that can also roll side-to-side and front-to-back based on sensor feedback, they have also moved the control mechanism up the leg using a cable-driven system, which lightens the foot making it easier to use.

We find the test apparatus almost as interesting as the prosthesis itself. The researchers had to come up with a way to measure the performance of the prosthesis when used to walk in an arc. The solution was the turn-table treadmill seen above.

If you have time, check out the video demonstration on the main article’s page which covers the leg and the treadmill build.

[via Reddit]