Insert Coin (Cell) To Play LedCade

May 6, 2019 by Roger Cheng 3 Comments

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.

Talking Washer Is A Clean Solution For The Visually Impaired

May 4, 2019 by Kristina Panos 27 Comments

Have you shopped for an appliance lately? They’re all LEDs, LEDs everywhere. You might say that manufacturers are out of touch with the utility of tactile controls. [Wingletang]’s fancy new washing machine is cut from this modern cloth. While it does have a nice big knob for selecting cycles, the only indication of your selection is an LED. This isn’t an issue for [Wingletang], but it’s a showstopper for his visually impaired wife.

They tried to make tactile signposts for her most-used cycles with those adhesive rubber feet you use to keep cabinet doors quiet. But between the machine’s 14(!) different wash cycles and the endlessly-rotating selector knob, the tactile map idea was a wash. It was time to make the machine talk.

For his very first microcontroller project, [Wingletang] designed a completely non-invasive and totally awesome solution to this problem. He’s using LDRs arranged in a ring to detect which LED is lit. Recycled mouse pad foam and black styrene keep ambient light from creating false positives, and double as enclosure for the sensor and support boards. As [Mrs. Wingletang] cycles through with the knob, an Arduino clone mounted in a nearby project box determines which program is selected, and a Velleman KA02 audio shield plays a recorded clip of [Wingletang] announcing the cycle number and description.

The system, dubbed SOAP (Speech Output Announcing Programmes), has been a great help to [Mrs. Wingletang] for about the last year. Watch her take it for a spin after the break, and stick around for SOAP’s origin story and walk-through videos.

It’s baffling that so few washers and dryers let you know when they’re finished. Don’t waste your time checking over and over again—Laundry Spy waits for the vibrations to end and sends you a text.

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Simple, Self-Contained LoRa Repeater In About An Hour

May 2, 2019 by Donald Papp 5 Comments

[Dave Akerman]’s interest in high-altitude projects means he is no stranger to long-range wireless communications, for which LoRa is amazingly useful. LoRa is a method of transmitting at relatively low data rates with low power over long distances.

Despite LoRa’s long range, sometimes the transmissions of a device (like a balloon’s landed payload) cannot be received directly because it is too far away, or hidden behind buildings and geography. In these cases a useful solution is [Dave]’s self-contained LoRa repeater. The repeater hardware is simple, and [Dave] says that if one has the parts on hand, it can be built in about an hour.

The device simply re-transmits any telemetry packets it receives, and all that takes is an Arduino Mini Pro and a small LoRa module. A tiny DC-DC converter, battery, and battery charger rounds out the bill of materials to create a small and self-contained unit that can be raised up on a mast, flown on a kite, or carried by a drone.

The repeater’s frequency and other settings can even be reprogrammed (using a small windows program) for maximum flexibility, making the little device invaluable when going hunting for landed payloads like the one [Dave] used to re-create a famous NASA image using a plastic model and a high-altitude balloon. Check out the details on the GitHub repository for the project and start mashing “add to cart” for parts at your favorite reseller.

A Physical Knob For Browser Tabs

April 30, 2019 by Brian Benchoff 35 Comments

If you’re like most of us, you have about twenty browser tabs open right now. What if there were a way to move through those tabs with a physical interface? That’s what [Zoe] did, and it’s happening with the best laptop ever made.

The hardware for this build is simply an Arduino and a rotary encoder, no problem there. The firmware on the Arduino simply reads the encoder and sends a bit or two of data over the serial port. This build gets interesting when you connect it to a Firefox extension that allows you to get data from a USB or serial port, and there’s a nice API to access tabs. Put all of this together, and you have a knob that will scroll through all your open tabs.

This build gets really good when you consider there’s also a 3D printed mount, meant to attach to a Thinkpad X220, the greatest laptop ever made. At the flick of a knob, you can scroll through all your tabs. It’s handy if you’re reading three or four or five documents simultaneously, or if you’re just editing video and trying to go through your notes at the same time. A great invention, and we’re waiting for this to become a standard device on keyboards and mice. Check out the video below.

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A Chrome Extension For Configuring RGB LEDs

April 28, 2019 by Tom Nardi 6 Comments

Like pretty much all of us, [Andy Schwarz] loves RGB LEDs. Specifically he likes to put them on RC vehicles, such as navigation lights on airplanes or flashers and headlights on cars. He found himself often rewriting very similar Arduino code for each one of these installations, and eventually decided he could save himself (and all the other hackers in the world) some time by creating a customizable Arduino firmware specifically for driving RGB LEDs.

The software side of this project, which he’s calling BitsyLED, actually comes in two parts. The first is the firmware itself, which is designed to control common RGB LEDs such as the WS2812 or members of the NeoPixel family. It can run on an Arduino Pro Mini with no problems, but [Andy] has also designed his own open hardware control board based on the ATtiny84 that you can build yourself. Currently you need a USBASP to program it, but he’s working on a second version which will add USB support.

With your controller of choice running the BitsyLED firmware, you need something to configure it. For that, [Andy] has developed a Chrome extension which offers a very slick user interface for setting up colors and patterns. The tool even allows you to create a visual representation of your LEDs so you can get an idea of what it’s going to look like when all the hardware is powered up.

RGB LEDs such as the WS2812 are some of the most common components we see in projects today, mainly because they’re so easy to physically interface with a microcontroller. But even though it only takes a couple of wires to control a large number of LEDs, you still need to write the code for it all. BitsyLED takes a lot of the hassle out of that last part, and we’re very interested to see what the hacker community makes of it.

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Driving A 16×2 LCD With Voltage Modulation

April 27, 2019 by Tom Nardi 18 Comments

The basic 16×2 LCD is an extremely popular component that we’ve seen used in more projects than we could possibly count. Part of that is because modern microcontrollers make it so easy to work with; if you’ve got an I2C variant of the display, it only takes four wires to drive it. That puts printing a line of text on one of these LCDs a step or two above blinking an LED on a digital pin on the hierarchy of beginner’s electronics projects.

What’s that? Even four wires is too many? In that case, you might be interested in this hack from [Vinod] which shows how you can drive the classic 16×2 with data and power on the same pair of wires. You’ll still need a microcontroller “backpack” for the LCD to interpret the modulated voltage, but if you’ve got an application for a simple remote display, this is definitely worth checking out.

The basic idea is to “blink” the 5 V line so quick that a capacitor on the LCD side can float the electronics over the dips in voltage. As long as one of the pins of the microcontroller is connected to the 5 V line before the capacitor, it will be able to pick up when the line goes low. With a high enough data rate and a large enough capacitor as a buffer, you’re well on the way to encoding your data to be displayed.

For the transmitting side, [Vinod] is using a Python script on his computer that’s sending out the text for the LCD over a standard USB to UART converter. That’s fed into a small circuit put together on a scrap of perfboard that triggers a MOSFET off of the UART TX line.

We actually covered the theory behind this technique years ago, but it’s always interesting to see somebody put together a real-world example. There might not be too many practical uses for this trick in the era of dirt-cheap microcontrollers bristling with I/O, but it might make a fun gag at your hackerspace.

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Vintage Camera Flash Turned OLED Desk Clock

April 19, 2019 by Tom Nardi 6 Comments

After covering a few of his builds at this point, we think it’s abundantly clear that [Igor Afanasyev] has a keen eye for turning random pieces of antiquated hardware into something that’s equal parts functional and gorgeous. He retains the aspects of the original which give it that unmistakable vintage look, while very slickly integrating modern components and features. His work is getting awfully close to becoming some kind of new art form, but we’re certainly not complaining.

His latest creation takes an old-school “Monopak” electronic flash module and turns it into a desk clock that somehow also manages to look like a vintage television set. The OLED displays glowing behind the original flash diffuser create an awesome visual effect which really sells the whole look; as if the display is some hitherto undiscovered nixie variant.

On the technical side of things, there’s really not much to this particular build. Utilizing two extremely common SSD1306 OLED displays in a 3D printed holder along with an Arduino to drive them, the electronics are quite simple. There’s a rotary encoder on the side to set the time, though it would have been nice to see an RTC module added into the mix for better accuracy. Or perhaps even switch over to the ESP8266 so the clock could update itself from the Internet. But on this build we get the impression [Igor] was more interested in playing with the aesthetics of the final piece than fiddling with the internals, which is hard to argue with when it looks this cool.

Noticing the flash had a sort of classic TV set feel to it, [Igor] took the time to 3D print some detail pieces which really complete the look. The feet on the bottom not only hold the clock at a comfortable viewing angle, but perfectly echo the retro-futuristic look of 50s and 60s consumer electronics. He even went through the trouble of printing a little antenna to fit into the top hot shoe, complete with a metal ring salvaged from a key-chain.

Late last year we were impressed with the effort [Igor] put into creating a retro Raspberry Pi terminal from a legitimate piece of 1970’s laboratory equipment, and more recently his modern take on the lowly cassette player got plenty of debate going. We can’t wait to see what he comes up with next.

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