The circuit is nothing wild – an ATtiny85 microcontroller interfaces a handful of buttons and LEDs to handle the basic Simon gameplay. The real value is in [APA]’s retelling of the development process. It’s an accurate recounting that makes us relive some of our own follies of early projects. There’s the confusion between SMD and through hole versions of the same part, forgotten pull up resistors, as well as hours lost trying to figure out why a chip won’t write, only to learn the bootloader hasn’t been burned yet.
In the end, [APA] was able to push through a rush order and deliver the gifts on time, despite the many pitfalls along the way. The final game provided some laughs around the dinner table at Christmas, so we’d say the mission was definitely accomplished.
While the current generation of smartwatches have only been on the market for a few years, companies have been trying to put a computer on your wrist since as far back as the 80s with varying degrees of success. One such company was Seiko, who in 1984 unveiled the UC-2000: a delightfully antiquated attempt at bridging the gap between wristwatch and personal computer. Featuring a 4-bit CPU, 2 KB of RAM, and 6 KB of ROM, the UC-2000 was closer to a Tamagotchi than its modern day counterparts, but at least it could run BASIC.
With extremely limited published information, and no toolchain, [Alexander] did an incredible job of figuring out the assembly required to interact with the hardware. Along the way he made a number of discoveries which set his plans back, such as the fact that there is no way to directly control individual pixels on the screen; all graphics would have to be done with the built-in symbols.
The culmination of all this hard work? Playing Tetris, naturally. Though [Alexander] admits that limitations of the device’s hardware meant the game had to be simplified a bit, he’s almost certainly having more fun than any of the UC-2000’s original owners did with this device. He’s setup a GitHub repository for anyone who wishes to join him in this brave new world of vintage wrist computing.
In the strongman game, you smash a lever with all your might using a hammer. A puck on the other end of the lever then shoots up a tower, hopefully high enough to hit a bell, winning you a prize. In [avishorp]’s games the puck, tower and bell are all replaced with an LED strip. In the swipe game, the faster you swipe your hand sideways over two optical proximity sensors, the higher the LEDs light up. In the drum game, the speed with which you drum on a rubber disk with embedded accelerometer, the higher the LEDs light up. The chase and response games both involve buttons that you have to rapidly hit, to similar effect.
For the brains, each game is controlled by an Adafruit Trinket board. [Avishorp] chose to use the PlatformIO IDE instead of the Arduino IDE to write them, preferring its modern editor, but he didn’t like that it doesn’t print and that it doesn’t tell you the final file size. The latter issue caused him to overwrite the bootloader, something that he understandably considered a major inconvenience.
Check out his page for more details, Fritzing diagrams, links to code, and all game videos. Meanwhile we’ve included clips of the drum and swipe games below.
And if it’s more carnival games you’re looking for, how about this adult-sized Sit ‘n Spin made using a rear differential and axle assembly out of an old car or truck. Or maybe you prefer something less likely to make you woozy, in which case you can try fishing with the Bass Master 3000.
[Mitxela] wanted to build a different kind of mouse, one that worked like an Etch-a-Sketch toy with one X knob and one Y knob. Armed with some rotary encoders and a microcontroller, that shouldn’t be hard. But when you use a pin-limited ATtiny85, you are going to need some tricks.
The encoders put out a two-bit Gray code and close a button when you depress them. Plus you need some pins for the V-USB stack to handle the USB interface. [Mitxela] decided to convert the encoders to output analog voltages using a simple resistor DAC. That would only require two analog inputs, and another anlaog input could read both switches.
One problem: there still wasn’t quite enough I/O. Of course, with AVRs you can always repurpose the reset pin as an analog pin, but you lose the ability to program the device at low voltage. And naturally, there’s a workaround for this too, allowing you to keep the reset pin and still read its analog value. You just have to make sure that value doesn’t go below about 2.5V so the device stays out of reset. Once that was in place, the rest went easy, as you can see in the video below.
DC to DC conversion has come a long way. What was once took an electromechanical vibrator and transformer has been reduced to a PC board the size of a largish postage stamp that can be had for a couple of bucks on eBay. So why roll your own buck-boost converter for the ground up? Maybe because sometimes the best way to learn is by doing.
[James Bellafaire] wanted a good looking old radio with a modern sound. Granted, you could hollow the case out and replace it with an iPod. Or you could convert the thing to an Internet radio. But where’s the fun in that?
[James] took a different approach. Part woodworking project, part Raspberry Pi project, and part microcontroller project, he wound up with a hard drive-based music player in a 1930’s case with knobs that control the playback.
To tackle the difficulty of discriminating between the different sounds from different sources, [Alex’s] wants to attach little sound sensors directly to the sound emitting devices. The sensors wirelessly communicate with the wristband. If the wristband receives a trigger signal from one of the sensors, it alerts the wearer by vibrating. It also shows which device triggered the alert by flashing an RGB LED in a certain color. A first breadboard prototype of his idea confirmed the feasibility of the concept.
After solving a few minor problems with the sensitivity of the sensors, [Alex] now has a working prototype. The wristband features a pager motor and is controlled by an ATMEGA168. Two NRF24L01+ 2.4 GHz wireless transceiver modules take care of the communication. The sound sensors run on the smaller ATTiny85 and use a piezo disc as microphone. Check out the video below, where Alex demonstrates his build: