__ __         __            ___           
  / // /__ _____/ /__  ___ _  / _ \___ ___ __
 / _  / _ `/ __/  '_/ / _ `/ / // / _ `/ // /
/_//_/\_,_/\__/_/\_\  \_,_/ /____/\_,_/\_, / 
retro edition                         /___/ 
Now optimized for embedded devices!
About Successes Retrocomputing guide Email Hackaday

Ask Hack a Day: Touch Screen Hack

posted Dec 3rd 2009 7:37am by
filed under: classic hacks, tablet pcs hacks

Reader [Chad Essley] asked us:

“I’m wondering if the vast knowledge base of HackADay’ers out there might know of some way to turn almost any laptop into a touch screen of some kind. Actually, any surface.”

He has an older Wacom Tablet, and would like to be able to add resistive touch screen capabilities so that he isn’t forced to use the Wacom pen. Being an artist and part time hacker, he even summed up the question in a comic-style post.

which allow “Clip on Tablet abilities”, however you have to use their pen, which doesnt help with the tablet problem, but may help with your “any monitor” problem. Another solution is to buy a generic touch screen kit (usually on eBay from somewhere in China), and install it yourself. That will work for most laptops and desktop monitors, however we wouldnt recommend using it with your Wacom tablet, as it would probably interfere with the pen functionality. Hak5 recently did an episode on Touchscreen kits, but there are also a number of places all over the internet to find step-by-step how-tos for kits.
We dont think you could use an infrared camera from the side like in your drawing, because it would be very difficult to calibrate (wouldnt be able to tell the difference between cold hands, and hands that are farther away/etc in our opinions). Things like the Microsoft Surface use infrared, but from underneath (which is much easier for machine vision to handle.) A flat, unlit surface (not like a monitor or a tablet) could use something similar to the laser keyboard.
We have also covered a couple of gesture and touch based input tools which may help out anyone willing to take on this task. TISCH is a top-down camera based multi-touch framework, and Scratch Input is a tool for using acoustic signals on a wall or a table to interpret touch and drag motions.
Unfortunately, that is about all the ideas we could come up with, but the Wikipedia page on Wacom tablets might be a good place to start for background information on what could or could not work with this configuration. Hopefully some of our ideas will spark the interests and specialties of our readers, feel free to respond in the comments, or send any ideas to our tip line!
Thanks again to [Chad] for his question, and feel free to send any other ideas for Ask Hack a Day.

USB Geiger counter hack

posted May 13th 2011 9:31am by
filed under: misc hacks


[Vic] bought a Kvarts DRSB-01 Geiger counter a few years ago, and recently dug it out of his electronics stash. The counter is a run of the mil no-frills unit. It lacks any kind of LCD display and it cannot be calibrated, so Sievert exposure ratings are out of the question. The unit essentially monitors background radiation and alerts the user to the presence of gamma and high-energy beta rays via audible clicks.

[Vic] wanted to make it a bit more useful, so he decided to interface it with his computer in order to take long-term radiation measurements. He dug up a schematic online and deadbugged a small circuit using an ATtiny44. The circuit allows him to enumerate the electrical pulses generated by ionizing particles striking the Geiger tube, passing them along to his PC over USB.

The counter seems to interface with the PC just fine, but [Vic] does say that he’s getting some odd readings. He thinks that he might have damaged the tube while messing around, but he’s all ears if you have any insight on the matter.

Using an LCD’s poor viewing angle to your advantage

posted Oct 24th 2011 7:01am by
filed under: video hacks

Early LCD monitors had some pretty awful issues when not viewed from directly in front of the screen. These days the technology has really minimized this flaw, but if you still have a cheap monitor on hand you might want to pull it out and give this hack a try. [Chris Harrison] is using oblique viewing angles to display additional information on cheap montiors.

Take a look at the two images above. The one on the left is taken from directly in front of the monitor and looks normal. But if you view the same screen from the side, the financial information is obscured. This is by design. Using very light colors, the obscuring characters are almost indiscernible from straight on, but you can just see them there a little bit (they look like burn-in does on a CRT screen). But from the side, these light colors become quite bold and blend with the rest of the data on the screen.

This works because of the polarizing filters on an LCD screen. You might want to watch [Bill Hammack] explain how an LCD works if you’re not familiar. Because the viewing angle color changes are a flaw and not a feature, manufacturers make the up-and-down angles the worst to improve on side-to-side viewing. [Chris'] experiments play into that by using a computer monitor on its side. Check out the video after the break to see some of the different applications that he uses this for.

Fog horn built from plumbing supplies

posted Jul 4th 2011 12:01pm by
filed under: misc hacks


Instructables user [rog8811] was looking to build a fog horn that resembled hand-pumped units found on small ships in the early to mid 1900s. His budget was a bit limited, so he set off to build the cheapest replica possible.

While the original horns were likely constructed from steel, copper and wood, he opted to use cheap plumbing components he found at his local hardware store. He used a simple double-acting air pump to drive the horn, combining it with a slightly modified bottle trap. The trap was shortened, and a diaphragm cut from a dish washing glove was added to generate sound.

He added a few more pieces of PVC piping to enhance the output, giving him the results you see in the video below. He says that the best thing about his design is the ability to easily tweak the pitch and volume of the horn by simply adding different drain components to the pump.

Watch out vuvuzela, there’s a new cheap and annoying horn on the block!

Maker Faire 2008: RoboGames and warships

posted May 9th 2008 4:10am by
filed under: cons

Today’s episode of BoingBoing TV comes straight from Maker Faire. The first segement is about RoboGames arena combat. The second segment covers a favorite exhibit of mine. Western Warship Combat Club brought their 1/144th scale battleships to fight it out in a large pool. The RC boats fire ammunition up to 1/4-inch ball bearings and the even feature bilge pumps to keep them afloat. Scoring is based on where on the hull the strike happens. Here’s a direct link to the mp4.

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