For this year’s office holiday party, [Gavan Fantom] wanted to do something really special. Coworkers were messing with LEDs to come up with displays and decorations, but they lack that old-school feel of mechanical displays. He wanted to create something that had retro look of moving elements, but didn’t want to just recreate the traditional flip mechanism we’ve all seen over and over.
Each element in the display is made up of seven 3D printed parts and two nails, which the mechanism slides on to move forward and backward. An 8×8 display needs 64 elements, which means the entire display needs 64 servos, 128 nails, and a whopping 448 3D-printed parts. Even with two printers attacking the production in parallel, the printing alone took over two weeks to complete.
The display is powered by a Raspberry Pi and three “Mini Maestro” controllers which can each handle 24 servos. [Gavan] found some sample code in Python to pass commands to the Maestro servo controllers, which he used as a template when writing his own software. The Python script opens image files, converts them to grayscale, and then maps the value of each pixel to rotation of the corresponding servo. He says the software is a little rough and that there’s still some calibration to be done, but we think the results are phenomenal so far.
Hackaday Belgrade — our first ever conference in Europe — is coming up fast. One of the really exciting things for me is the hardware badge which [Voja Antonic] designed for the conference. He’s done a great job with hardware choices and I think we’ve hit the sweet spot for badge hacking. Let’s jump into the hardware and firmware details after the break.
Get your ticket now for ten hours of talks and workshops, evening concerts, and of course badge hacking the entire time. Earlybird sales close Monday. We’re still in the process of going through talk proposals but we’ll publish a post next week announcing all of the speakers.
[Vince] teaches an Embedded Systems class at the University of Maine, and some of his students were working on video games for their finals. He decided to “test the hardware” that the students were using by putting two 8×8 displays, one 4×7 segment display, and a Wii Nunchuck on the I2C bus. He then wrote a version of Tetris that accepts trigger presses and accelerometer input for control. Judging by the video (embedded after the break), the Raspberry Pi runs the game without issue. The bus is, of course, more than capable of handling everything.
Unfortunately, [Vincent] had some trouble getting the controls just right. Sometimes dropping a piece can cause the next to drop too quickly, and the accelerometer control seems a bit too sensitive. We imagine using the joystick for rotation and adding some strategic pauses in the game could help. He graciously released the source code for the project, so maybe we’ll see some embracing and extending in the near future.
If all [Blake] wanted to do is scroll “Blake loves Kim” on some LEDs he could have stopped with the breadboard version of the project. Or hastily craft a cardboard heart around the marquee. But he really just used this heart-shaped electronics project as an excuse to get his feet wet with several different types of manufacturing.
The project started as a simple scrolling message pendant. Something along these lines. His very small LED module was being driven by an ATtiny85. He planned to run it from battery which is a perfect excuse to learn how to use the sleep functions built into the chip.
The initial design worked so well he decided to lay out his own circuit board. This made it quite simple to add in a side-positioned button to wake from sleep, and a coin cell battery holder on the back. He used OSH Park for board manufacturing — good thing they allow creative board outlines. To protect the circuitry he also ordered laser-cut acrylic plates that work in conjunction with stand offs to form a case.
He mentions he missed his Valentine’s Day delivery date by a long shot. But that’s how these sort of things go, right?
Simple tools used well can produce fantastic results. The hardware which [Gilad] uses in this project is the definition of common. We’d bet you have most if not all of them on hand right now. But the end product is a light box which seems to dance and twirl with every sound in the room. You should go watch the demo video before reading the bill of materials so that the simplicity doesn’t spoil it for you.
A wooden craft box serves as the enclosure. Inside you’ll find an Arduino board, microphone, and an 8×8 RGB module. The front cover of the project box diffuses the light using a sheet of tracing paper on a frame of foam board. It’s the code that brings everything together. He wrote his own particle system library to generate interesting animations.
[Jason] has been hard at work on this Arduino-based low-res gaming platform. He even had a fab house deliver circuit boards to pull everything together. It’s a little small in his hands, and the graphics are limited to the 8×8 pixels provided by the display. But it still looks like a lot of fun and the code was written to make adding new games quite painless.
The board hosts an ATmega328 which drives the bi-color LED display using a pair of TPIC6B595 shift registers. Control is provided by a collection of buttons to either side of the display. The unit is powered by three AAA batteries held in a pack soldered to the back side of the PCB.
The image above shows [Jason] giving a Space Invaders game a try. The clip after the break shows respectable action, sound from a piezo buzzer, and it even scrolls your score at the end of the game. But you’re not limited to just one title. Adding new games is as easy as implementing a class in a new header file. You can get a feel for how this is set up by viewing the source code repo.
This is the back side of [Dmitry Grinberg’s] 8×8 LED matrix pendant. He had seen the other projects that used a 5×7 grid but wasn’t really satisfied with the figures that can be drawn in that confined area when each pixel has only the option of being on or off. His offering increases the drawing area and includes the ability to display each pixel at several different levels.
He’s using an ATmega328 microcontroller soldered directly to the pins on the back of the LED module. He mapped out the IO in his firmware to make the soldering as easy as possible. To protect the hardware he fashioned a mold around the edges of the LED package using duct tape. The tape held epoxy in place as it hardened, encasing the microcontroller and holding the power wires and ICSP header tightly.
After the break you can see about six seconds of the device in action. The four levels of brightness for each pixel really do make quite a difference!