[David Johnson-Davies] created a minimal Secret Maze Game using a single ATTiny85 and a few common components. This simple game uses four buttons, four LEDs, and a small speaker. The player moves in the four cardinal directions using buttons, and the LEDs show walls and corridors. If an LED is lit, it means the path in that direction is blocked by a wall, and attempting to move in that direction will make a beep. When the player reaches the exit, a short victory tune chirps from the speaker.
Since the ATTiny85 has only five I/O lines, [David] had to get a bit clever to read four buttons, display output on four LEDs, and drive a little speaker. The solution was to dedicate one pin to the speaker and the other four to charlieplexing, which is a method of driving more LEDs than you have pins. It takes advantage of the fact that most microcontroller pins can easily switch state between output high, output low, or low-impedance high-impedance input.
As for the buttons, [David] charlieplexed them as well. Instead of putting an LED in a charlieplexed “cell”, the cell contains a diode and an SPST switch in series with the diode. To read the state of the switch, one I/O line is first driven low and the other I/O line is made an input with a pullup. A closed switch reads low on the input, and an open switch reads high. With charlieplexing, four pins is sufficient for up to twelve LEDs (or buttons) in any combination, which is more than enough for the Secret Maze.
What if we told you that you are likely to have more computers than you think? And we are not talking about things that are computers while not looking like one, like most modern cars or certain lightbulbs. We are talking about the powerful machines hiding in your desktop computer called ‘graphics card’. In the ordinary gaming rig graphics cards that are much more powerful than the machine they’re built into are a common occurrence. In his tutorial [Viktor Chlumský] demonstrates how to harness your GPU’s power to solve a maze.
Software that runs on a GPU is called a shader. In this example a shader is shown that finds the way through a maze. We also get to catch a glimpse at the limitations that make this field of software special: [Viktor]’s solution has to work with only four variables, because all information is stored in the red, green, blue and alpha channels of an image. The alpha channel represents the boundaries of the maze. Red and green channels are used to broadcast waves from the beginning and end points of the maze. Where these two waves meet is the shortest solution, a value which is captured through the blue channel.
Despite having tons of cores and large memory, programming shaders feels a lot like working on microcontrollers. See for yourself in the maze solving walk through below.
[Jason Carlson]’s favorite game as kid was 1983’s Treasure of Tarmin by Intellivision, a maze game that eventually came to be called Minotaur. As an adult there was only one thing he could do: remake it on a beautiful Arduino-based handheld.
[Jason] built the handheld out of a small-footprint Arduino Mega clone, a 1.8” LCD from Adafruit, a 5 V booster, a 1” speaker and vibe motor for haptic feedback. There are some nice touches, like the joystick with a custom Sugru top and a surprisingly elegant 2 x AA battery holder — harvested from a Yamaha guitar.
The maze maps are all the same as the original game, which [Jason] found online, but he stored the maps as bytes in an array to speed up the game—there was a flicker in the refresh already. However he added a progress map so players could see every area that was explored. In addition to Minotaur [Jason] also added remakes of Tetris, Simon and Snake, simpler games he wrote to test out the hardware.
Dr. Claude E. Shannon was born 100 years ago tomorrow. He contributed greatly to the fields of engineering, communications, and computer science but is not a well known figure, even to those in the field. However, his work touches us all many times each day. The network which delivered this article to your computer or smartphone was designed upon important theories developed by Dr. Shannon.
Shannon was born and raised in Michigan. He graduated from the University of Michigan with degrees in Mathematics and Electrical Engineering. He continued his graduate studies at Massachusetts Institute of Technology (MIT) where he obtained his MS and PhD. He worked for Bell Laboratories on fire-control systems and cryptography during World War II and in 1956 he returned to MIT as a professor.
Shannon’s first impactful contribution was his masters thesis which took the Boolean Algebra work of George Boole and applied it to switching circuits (then made up of relays). Before his work there was no formal basis for the analysis of switching systems, like telephone networks or elevator control systems. Shannon’s thesis developed the use of symbolic notation to represent networks and applied simplifying rules to optimize the system. These same rules later translated to vacuum tube and transistor logic aiding in the development of today’s computer systems. The thesis — A Symbolic Analysis of Relay and Switching Circuits — was completed in 1937 and subsequently published in 1938 in the Transactions of the American Institute of Electrical Engineers.
Shannon’s doctoral work continued in the same vein of applying mathematics someplace new, this time to genetics. Vannevar Bush, his advisor, commented, “It occurred to me that, just as a special algebra had worked well in his hands on the theory of relays, another special algebra might conceivably handle some of the aspects of Mendelian heredity”. Shannon’s work again is revolutionary, providing a mathematical basis for population genetics. Unfortunately, it was a step further than geneticists of time could take. His work languished, although interest increased over time.
Play your favorite Atari Jaguar games on an FPGA thanks to the work [Gregory Estrade] did to get it running on a Stratix-II board. You can pick up the VHDL and support tools in his repo. If you’re just curious you can watch his demo vid.
Members of Open Space Aarhus — a hackerspace in Risskov, Denmark — have been playing around with a bunch of old server fans. They made a skirtless hovercraft by taping them together and letting them rip. Too bad it can’t carry its own power supply
And finally, here’s a unique chess board you can build by raiding your parts bin. [Tetris Monkey] made the board from the LCD screen of a broken monitor. The playing pieces are salvaged electronics (like big capacitors) against corroded hardware (like nuts and bolts). We think it came out just great!
[Martin Raynsford] figured out a way to sneak some learning into a fun package. He did such a good job the test subjects didn’t even know they were teaching themselves just a tiny bit of CNC programming.
He showed off the rig at the Maker Faire. It takes simple commands as cardinal directions and units of movement. The ‘player’ (remember, they’re secretly learning something, not just playing a game) inputs a series of movements such as “N10,E10” which are then pushed through a serial connection to the Arduino. It follows these commands, moving the hidden magnet which drags the ball bearing along with it. It’s simple, but watch the clip after the break and we think you’ll agree the sound of the stepper motors and the movement of the ball will be like crack for young minds.
Part of the fun of the classic game of Operation is the jump you get from the loud buzzer which sounds if you touch the sides. This exhibit piece uses the same principle of lining the edges of a track with metal, but instead of an annoying buzz, each touch will issue a bit of music. That’s because the maze has been paired with a synthesizer. Instead of one sound wherever the stylus touches the sides, different parts of the maze act as one of 94 keys for the synthesizer.
There’s a lot more built into the base of the device than just a maze game. The knobs are used to alter the audio effects and the buttons work in conjunction with they stylus to sequence audio samples. There’s even a graphic LCD screen which shows the currently playing wave form. You can get a better look at the project in the video after the break.