We sure wish we’d had a teacher like [Volos Projects]. He built this beautiful circuit sculpture to teach his students how to count in binary and convert it to decimal and hexadecimal. If you don’t already know binary, you get to learn it on DIP switches and a dead-bugged ATMega328 in the video after the break. Lucky you!
Once the students have the hang of entering binary input on the switches, they can practice it on the four-banger calculator. This educational sculpture can also take text input and scroll it, but it takes a bit of work. You have to look up the ASCII value of each character, convert the decimal to binary, and program it in with the switches. There’s one more function on the menu — a one-player PONG game to help the students relax after a long day of flipping switches.
Funny enough, this project came to be after [Volos Projects] came upon the DIP switch in his parts box and wasn’t quite sure what it was called. How great is it that he learned something about this part, and then used that knowledge to build this machine that uses the part to teach others? It’s surely the best fate that parts bin curiosities can hope for.
It’s a simple enough device, with an ATmega328, an off-the-shelf MP3 module, and a power supply regulator to deliver 5 V into a pair of supercapacitors from the vehicle accessory socket’s 12 V. The idea is that the power is cut when the vehicle ignition is turned off, and that the supercaps have enough energy within them to play the reminder sample for the driver to check for forgotten children.
We can’t help remarking that a percentage of cars leave their accessory sockets turned on all the time, so it would be interesting to ponder how one might detect the car being turned off in that case. He muses about using a surplus cell phone instead of his ATmega328, perhaps the MEMS sensor on a phone could also be used to detect the vibrations of the engine stopping as it was turned off. Such cars notwithstanding, this unit is a straightforward solution to the problem in hand.
As [sjm4306] says, “You can never have too many clocks based on obsolete display technologies.” We couldn’t agree more, and this single-tube VFD clock is one we haven’t seen before.
The vacuum-fluorescent display that [sjm4306] chose to base this clock on is the IV-21, an eight-digit seven-segment display on the smallish side. The tube is Russian surplus from the ’80s, as all such displays seem to be. The main PCB sports an ATMega328, a boost converter to provide the high voltage needed to run the VFD, a real-time clock, and the driver chip for the tube segments. The tube itself lives on a clever riser card that elevates the display above the main PCB and puts it at the proper angle for reading. [sjm4306] designed it to be modular; should you want to user a bigger VFD you need only make a new riser PCB. Figuring out the proper way to space the through-holes in Eagle proved elusive, but he hacked a solution using a spreadsheet to handle the trigonometry and spit out Cartesian coordinates for each hole. Pretty neat. The video below shows the clock assembly and a test.
Free-form circuitry built as open wire sculpture can produce beautiful pieces of electronics, but it does not always lend itself to situations in which it might be placed under physical stress. Thus the sight of [Mile]’s free-form wristwatch is something of a surprise, as a wristwatch cam be exposed to significant mechanical stress in its everyday use.
The electronic side of this watch is hardly unusual, the familiar ATmega328-AU low-power microcontroller drives a tiny OLED display. Mechanically though it is a different story, as the outline of a wristwatch shell is traced in copper wire with a very neat rendition of a Wrencher in its base, and a glass lens is installed over the screen to take the place of a watch glass. A strap completes the wristwatch, which can then be worn like any other. Power comes from a small 110 mAh lithium-polymer cell, which it is claimed gives between 6 and 7 hours of on time and over a month of standby with moderate use.
Unfortunately there does not seem to be much detail about the software in this project, but since ATmega328 clocks and watches are ten a penny we don’t think that’s a problem. The key feature is that free-form construction, and for that we like it a lot.
The main body of the handheld is constructed from attractive black and gold PCBs, and features a screen, some controls and an on/off switch. There’s also a microSD socket is on the board, which interfaces with cartridges which carry the microcontroller. Change the cart, and you can change the game.
[bobricius] has developed carts for a variety of common microcontroller platforms, from the Attiny85 to the venerable ATmega328. As the microSD slot is doing little more then sharing pins for the screen and controls, it’s possible to hook up almost any platform to the handheld. There’s even a design for a Raspberry Pi cart, just for fun.
In this era of 4K UHD game console graphics and controllers packed full of buttons, triggers, and joysticks, it’s good to occasionally take a step back from the leading edge. Take a breath and remind ourselves that we don’t always need all those pixels and buttons to have some fun. The LedCade is a μ (micro) arcade game cabinet built by [bobricius] for just this kind of minimalist gaming.
Using just three buttons for input and an 8×8 LED matrix for output, the LedCade can nevertheless play ten different games representing classic genres of retro arcade gaming. And in a brilliant implementation of classic hardware hacking humor, a player starts their game by inserting not a monetary coin but a CR2032 coin cell battery.
Behind the screen is a piezo speaker for appropriately vintage game sounds, and an ATmega328 with Arduino code orchestrating the fun. [bobricius] is well practiced at integrating all of these components as a result of developing an earlier project, the single board game console. This time around, the printed circuit board goes beyond being the backbone, the PCB sheet is broken apart and reformed as the enclosure. With classic arcade cabinet proportions, at a far smaller scale.
If single player minimalist gaming isn’t your thing, check out this head-to-head gaming action on 8×8 LED arrays. Or if you prefer your minimalist gaming hardware to be paper-thin, put all the parts on a flexible circuit as the Arduflexboy does.
The concept of a smartwatch was thrown around for a long time before the technology truly came to fruition. Through the pursuit of miniaturisation, modern smartwatches are sleek, compact, and remarkably capable for their size. Companies such as Apple and Samsung throw serious money into research and development, but that doesn’t mean you can’t create something of your own. [Electronoobs] has done just that, with this Arduino-based smartwatch build.
The brain of the watch is that hacker staple, the venerable ATmega328, most well known for its use in the Arduino Uno and Nano platforms. An FTDI module is used for USB communication, making programming the board a snap. Bluetooth communication is handled by another pre-built module, and a smartphone app called Notiduino handles passing notifications over to the watch.
This is a build that doesn’t do anything crazy or difficult to understand, but simply combines useful parts in a very neat and tidy way. The watch is impressively thin and compact for a DIY build, and has a host of useful functions without going overboard.