Engraved acrylic lights up nicely with LED lighting. Simply engrave clear acrylic with a laser engraver, then edge-light the acrylic and watch the engraving light up. This badge made by [Solarbotics] shows how they used this principle when creating some pendants for an event that performed particularly well in the dark.
The pendants they created have two engraved acrylic panels each, and that’s about it. Two LEDs and a CR2032 battery nestle into pre-cut holes, and the engraved sides are placed face-to-face, so the outer surfaces of the pendant are smooth. By using some color-cycling RGB LEDs on one panel and blue LEDs on the other panel, the effect is that of an edge-lit outer design with a central element that slowly changes color separately from the rest of the pendant.
The design stacks the LED leads and coin cells in such a way that a simple wrap of tape not only secures things physically, but also takes care of making a good electrical connection. No soldering or connectors of any kind required. [Solarbotics] found that CR2032 cells would last anywhere between a couple of days to a week, depending on the supplier.
This design is great for using a minimum of materials, but if that’s not a priority it’s possible to go much further with the concept. Multiple layers of edge-lit acrylic were used to make numeric 0-9 display modules as well as a full-color image.
As pinball has evolved, it has gone from a simple gravity based game to an electromechanical one. As the 20th century came to a close, pinball games added digital elements as well, matrix displays replaced electromechanical scoreboards, and LEDs replaced incandescent bulbs. While the game got more creative as new technologies became available, the basics of the pinball never changed – keep the ball alive using your skill with the flippers (and the occasional nudge.) [Garagem Fab Lab] has taken the basics of the pinball machine and, with some wood and elastic bands, has created a very nice desktop pinball machine.
The plans for the game require getting the wood cut by a CNC mill, but they could probably be easily created using a jigsaw. Instead of electrical buttons and solenoids, pieces of wood push the flippers out and elastics reset them when released. The bumpers, too, are simple dowels with rubber bands wrapped around them. The launching mechanism is a bit of bungee cord tied onto a piece of wood and used like a flipper to speed the ball into the play area.
The build is a throwback to the earliest pinball machines. Sure, there’s no reaction from the bumpers when they’re hit, they’re just passive, but the game looks fun. It would be a great base to add in some sensors, a microcontroller, and a display to keep track of scores if one was so inclined. Other DIY pinball machines we’ve seen are this pinball game built with Meccano and lasers, as well as this completely 3D-printed machine.
[Marc] has an old Voigtländer Vito CLR film camera. The camera originally came with an analog light meter built-in. The meter consisted of a type of solar panel hooked up to a coil and a needle. As more light reached the solar panel, the coil became energized more and more, which moved the needle farther and farther. It was a simple way of doing things, but it has a down side. The photo panels stop working over time. That’s why [Marc] decided to build a custom light meter using newer technology.
[Marc] had to work within the confines of the tiny space inside of the camera. He chose to use a LM3914 bar display driver IC as the primary component. This chip can sense an input voltage against a reference voltage and then display the result by illuminating a single LED from a row of ten LEDs.
[Marc] used a photo cell from an old calculator to detect the ambient light. This acts as a current source, but he needed a voltage source. He designed a transimpedence amplifier into his circuit to convert the current into a voltage. The circuit is powered with two 3V coil cell batteries, regulated to 5V. The 5V acts as his reference voltage for the display driver. With that in mind, [Marc] had to amplify this signal further.
It didn’t end there, though. [Marc] discovered that when sampling natural light, the system worked as intended. When he sampled light from incandescent light bulbs, he did not get the expected output. This turned out to be caused by the fact that incandescent lights flicker at a rate of 50/60 Hz. His sensor was picking this up and the sinusoidal output was causing problems in his circuit. He remedied this by adding two filtering capacitors.
The whole circuit fits on a tiny PCB that slides right into position where the original light meter used to be. It’s impressive how perfectly it fits considering everything that is happening in this circuit.
This robot arm and gripper is made almost entirely out of silicone. Casting the parts by hand, [Mike] assembled this working, remote controlled robot arm gripper.
We’ll let that sink in for a minute. He turned an oversized tooth-paste tube of silicone caulking… into a pneumatic robotic arm. Holy cow. We’ve seen lots of soft robotics before, but this is some really cool stuff!
You see, [Mike] is actually planning on building an inexpensive prosthetic robot hand using this technology. This was merely a test to see how well he could make silicone based air muscles — we’d say it was pretty successful! Each silicone disk in this robotic appendage has four sealed pockets inside of it. When air flows in through them, they inflate, causing the entire appendage to stretch on one side. With four of these, and varying amounts of pressure, it’s possible to move the appendage in any direction!
Continue reading “Soft and Squishy Silicone Robotics”
[Pariprohus] wanted to make an interesting gift for his girlfriend. Knowing how daunting it can be to make your own tea, he decided to build a little robot to help out. His automated tea maker is quite simple, but effective.
The device runs off of an Arduino Nano. The Nano is hooked up to a servo, a piezo speaker, an LED, and a switch. When the switch is turned to the off position, the servo rotates into the “folded” position. This moves the steeping arm into a position that makes the device easier to store and transport.
When the device is turned on to the “ready” position, the arm will extend outward and stay still. This gives you time to attach the tea bag to the arm and place the mug of hot water underneath. Finally the switch can be placed into “brew” mode. In this mode, the bag is lowered into the hot water and held for approximately five minutes. Each minute the bag is raised and lowered to stir the water around.
Once the cycle completes, the Nano plays a musical tune from the piezo speaker to remind you to drink your freshly made tea. All of the parameters including the music can be modified in the Nano’s source code. All of the components are housed in a small wooden box painted white. Check out the video below to see it in action. Continue reading “Automated Tea Maker”
Are you tired of being ignored? Do you want a fashion accessory that says, “Pay attention to me!” If so, you should check out [Al’s] recent instructable. He’s built himself a necklace that includes a display made up of 512 individual LEDs.
This project was built from mostly off-the-shelf components, making it an easy beginner project. The LED display is actually a product that you can purchase for just $25. It includes 512 LEDs aligned in a 16 x 32 grid. The module is easily controlled with a Pixel maker’s kit. This board comes with built-in functionality to control one of these LED modules and can accept input from a variety of sources including Android or PC. The unit is powered from a 2000 mAH LiPo battery.
[Al] had to re-flash the firmware of the Pixel to set it to a low power mode. This mode allows him to get about seven hours of battery life with the 2000 mAH battery. Once the hardware was tested and confirmed to work correctly, [Al] had to pretty things up a bit. Some metallic gold spray paint and rhinestones transformed the project’s cyberpunk look into something you might see in a hip hop video, or at least maybe a Weird Al hip hop video.
The Pixel comes with several Android apps to control the display via Bluetooth. [Al] can choose one of several modes. The first mode allows for pushing animated gif’s to the display. Another will allow the user to specify text to scroll on the display. The user can even specify the text using voice recognition. The final mode allows the user to specify a twitter search string. The phone will push any new tweets matching the terms to the display as scrolling text.
Having the right tool for the job makes all the difference, especially for the types of projects we feature here at Hackaday. [Jan_Henrik’s] must agree with this sentiment, one of his latest projects involves building a tool to generate a PWM signal and test servos using an Attiny25/45/85.
Tools come in all kinds of different shapes and sizes. Even if it might not be as widely used as [Jan_Henrik’s] earlier work that combines an oscilloscope and signal generator, having a tool that you can rely upon to test servos and generate a PWM can be very useful. This well written Instructable provides all the details you need to build your own, including the schematic and the necessary code (available on GitHub). The final PWM generator looks great. For simple projects, sometimes a protoboard is all you need. It would be very cool to see a custom PCB made for this project in the future.
What tools have you build recently? Indeed, there is a tool for every problem. Think outside the (tool) box and let us know what you have made!