Projection Screen Using Latex Paint And Sand Blasting Beads

This method of building your own projection screen is new to us. [Sean Michael Ragan] ran across some sand blasting material made up of minuscule glass beads at Harbor Freight and inspiration struck. He purchased a fifty-pound bag and set out to see if it could be used with regular latex paint to create a projection screen. The answer is an absolute yes, but results are dependent on how you apply it.

Now there is paint you can buy which will turn your wall into a projector screen, but it’s expensive. [Sean’s] hack isn’t a direct replacement as he found the results of just mixing the beads with paint and applying them to a vertical surface weren’t up to the standards he’s looking for. But if you build a screen to hang on the wall you can let gravity work for you. He laid the screen flat and applied a heavy coat of paint to the surface. He then sprinkled a heavy coat of the glass bead over the wet paint and let it dry. Finally he cleaned off the material which didn’t stick and hung it on the wall.

Don’t have a projector to use with this hack? No problem, just build your own.

[Thanks Skuhl]

Up Your FPGA Game By Learning From This LCD Control Prototype

[Cesar] recently got a PSP display up and running with his FPGA development board. That’s a nice project, but what we really like is that he set aside a lot of time to show how it’s done every step of the way. This isn’t just a tutorial on that particular screen, but an overview of the skill set needed to get any piece of hardware working.

The screen itself is a Sharp LQ043T3DX02; a 480×272 TFT display with 16 million colors. Not bad for your project but when you start looking into the control scheme this isn’t going to be like using a Nokia screen with an Arduino. It takes twenty pins to control it; Red, green, and blue take sixteen pins, four pins are used for control, the rest are CK, DISP, Hsync, Vsync.

Wisely, [Cesar] designs his own interface board which includes the connector for the ribbon cable. It also has drivers for the screen’s backlight and supplies power to the device. With hardware setup complete he digs into the datasheets. We just love it that he details how to get the information you’re looking for out of this document, and shows his method of turning that first into a flow chart and then into code for the FPGA.

Retro Hardware Mash-up Spouts Archaic Geekery

This delightful little box is something only a hacker could love. It uses some second-hand hardware to display random sayings attributed to [Buckminster Fuller]. The image above doesn’t do the display justice. There are other photos which show very crisp lettering which is easier to read.

[Autuin] always keeps his eyes open for cool gear at the end of its consumer life. The screen for this project is a CRT from a Coleman TV lantern (you know, for camping… bah!). It finds a home in the chassis of an old non-functional radio he had picked up a few years earlier. With those parts in hand the real adventure started: getting an Arduino to read in quotes and generate a TV out signal to display them.

We love the SD card holder which he fashioned from a card-edge connector he grabbed at the local electronics store. From there he scoured the Internet for help on where to patch into the TV signal. Once the right trace was discovered the Arduino TV out library does the heavy lifting.

Automatic Water For Your Pets

If you have livestock or outdoor pets you know how important it is to keep them watered, but also know that sometimes you are not around when the trough runs dry. [Buddy] solves this inconvenience with a trip to the hardware store and some creativity.

The automatic water filler is made from some PVC pipe, brass fittings, a faucet supply and a toilet float valve. The PVC is arranged into a hook shape, a fitting is put on one end for a standard garden hose. On the other end a bit of adapting is needed to convert the PVC into a faucet supply, where the toilet valve is hooked up. Now whenever your thirsty beasts get the water too low, the float lowers and tops off the watering hole with fresh H20. That sure beats running out there every day to make sure, especially with summer just around the bend.

Live Out Your Inner Animist With Animatronic Cat Ears

While having a great white shark as your spirit animal may sound cool, we’ve found walking around in public wearing a gigantic set of mechanical jaws to be a bit of a hindrance. [abetusk] doesn’t have that problem; he can wear his awesome animatronic cat ears anywhere he pleases.

The build was inspired by these extremely Japanese animatronic ears loaded with EEG hardware to read the emotional state of the wearer. [abetusk] decided that tearing apart some brain scanning hardware was too much work for not enough benefit, so he decided servos controlled by push buttons would be just fine.

On the electronic side of the build, servos attached to a head band are controlled by an ATtiny13. A single button goes through three states for the ears: a long button press is surprise, a tap followed by a long hold is angry or sad, and tapping three times is an ‘ear wink.’ All of the code is up on GitHub, and you can check out these cat ear emotions with [abetusk]’s lovely assistant in the video after the break.

Continue reading “Live Out Your Inner Animist With Animatronic Cat Ears”

Hacking Together A Color Changing Water Wall

[BadWolf’s] girlfriend wanted him to build her a lamp for Christmas and he didn’t disappoint. What he came up with is a water-filled color changing lamp with bubbles for added interest. See for yourself in the clip after the jump.

The color changing properties are easily taken care of by some waterproof RGB LED strips. [BadWolf] went the Arduino route for this project but any microcontroller will be able to fill the role of color cycling. The enclosure is all hand-made from acrylic sheets. He grabbed some chemical welding liquid from the hardware store and applied it to the acrylic with a syringe. That’s easy enough when attaching the edges to one side of the enclosure. But it gets much tougher when it’s time to seal up the other side. He recorded a video of this which shows the syringe taped to a rod so he can get it down in there, pushing the plunger with a second extension device.

Bubbles are supplied by a small aquarium pump. We’re wondering if this will need frequent cleaning or if you can get some pool chemicals to keeps it nice and clear (or just a teaspoon of bleach)? Continue reading “Hacking Together A Color Changing Water Wall”

Data Broacasting “Transparency Grenade” Ads Whimsy To Your Meetings

If you’re tired of underhanded deals going down behind closed doors maybe you need to start carrying around this transparency grenade. The enclosure is modeled after a Soviet-era F1 Hand Grenade. But it’s not filled with explosives and won’t send deadly shrapnel around the room. Instead, when the pin is pulled it starts recording audio and sniffing network packets, then broadcasts both to a remote server. Perhaps you could consider this to be data shrapnel sent around the world.

The exploded parts image above shows what hardware is at use. There’s a Gumstix board at the heart of the device which uses a WiFi module for sniffing and broadcasting data. The LED bar graph which you see in the fully assembled unit shows the wireless signal strength.

It sounds like the enclosure itself was 3D printed from Tusk2700T translucent resin but we’re a little confused by this part of the hardware description. We don’t have much of a need to transmit recordings of our meetings, but we’d love to use this case design for that MP3 enclosure.

[via Reddit]