Minimum Viable 1-D PONG

June 8, 2018 by 4 Comments

What makes a game a game? Like, how do we know that we’re looking at a variation of PONG when confronted with one? And how do we know how to play it? [Bertho] sought to answer this question as he designed what is probably the smallest-ever 1-D PONG game. His answer involves charlieplexing LEDs, using a voltage divider to save I/O pins, and a couple of AAAs that should last for a long, long time.

[Bertho]’s Minimum 1-D PONG, or m1dp for short, puts an ATTiny85 through its paces as gameplay quickly progresses from ‘I got this’ to ‘no one could possibly keep this up’. This state machine sleeps until one of the two buttons is pressed, at which time a wait animation starts. The action begins with the next button press.

Game play across only five LEDs makes for some pretty intense action, too. Fortunately, the buzzer is a big part of the experience. It sounds one tone for each LED when the ball is in play, and a different tone to confirm button presses. [Bertho] saved so many I/O pins with charlieplexing that he added a green LED that lights up when it’s OK to return the ball. If we were playing, we’d keep our eye on this LED instead of trying to watch the ball. We’re serving the demo after the break point, so don’t let it get past you.

For a study in minimalism, there sure is a lot going on here with all the different tones and animations. If you’d prefer maximalist 1-D PONG, there’s always LED strips. If dungeon crawlers with satisfying hardware are more your thing, you really need to check out Twang.

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VCF East 2018: SDR On The Altair 8800

June 8, 2018 by 34 Comments

You’d be forgiven if you thought software defined radio (SDR) was a relatively recent discovery. After all, few outside of the hardcore amateur radio circles were even familiar with the concept until it was discovered that cheap USB TV tuners could be used as fairly decent receivers from a few hundred MHz all the way up into the GHz range. The advent of the RTL-SDR project in 2012 brought the cost of entry level SDR hardware from hundreds of dollars to tens of dollars effectively overnight. Today there’s more hackers cruising the airwaves via software trickery than there’s ever been before.

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Who Said Thermal Cameras Weren’t Accessible To The Masses?

June 8, 2018 by 35 Comments

Thermal cameras hold an enduring fascination as well as being a useful tool for the engineer. After all, who wouldn’t want to point one at random things around the bench, laughing with glee at finding things warmer or colder than expected? But they’ve always been so expensive, and a lot of the efforts that have sought to provide one for little outlay have been rather disappointing.

This has not deterred [Offer] though, who has made an extremely professional-looking thermal camera using an M5Stack ESP32-based computer module and an AMG8833 thermal sensor array module in a 3D-printed case that copies those you’d find on a commercial unit. The modular approach makes it a simple prospect for the constructor, the software can be found on GitHub, and the case files are hosted on Thingiverse. You’ll be finding warm and cold things on your bench in no time, as the video below shows.

Most of the thermal cameras we’ve seen have centred upon the FLIR Lepton module, but that’s a component that remains expensive. This project shows us that thermal cameras are a technology that is slowly becoming affordable, and that greater things are to come.

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The random logic section implmented using I2L

Space Invaders Sound Chip Went Old School With I2L

June 8, 2018 by 6 Comments

It must be everyone’s birthday today because [Ken Shirriff] has come out with a gift for us. He’s done another pass at reverse engineering the 76477 Space Invaders sound chip from the 1970s and found it’s full of integrated injection logic (I2L), making it a double treat: we get to explore the more of this chip which made sounds for so many of our favorite games, and we explore a type of logic which was to be the successor to TTL until CMOS came along.

I<sup>2</sup>L gate
I2L gate

This article has a similar shape to his last one, first introducing I2L, followed by showing us what it looks like on the die, and then covering the different functional elements which make heavy use of it. The first of these is the noise generator made up of a section of shift registers and a ring oscillator. That’s followed by a noise filter which doesn’t use I2L but does use current mirrors. And lastly, he talks about the mixer which mixes output from the noise generator and elements covered in his previous article, the voltage-controlled oscillator, and the super-low frequency oscillator. Oddly enough, and as he points out, it isn’t an analog mixer. Instead, it just ANDs together the various inputs.

[Ken’s] no stranger to putting dies under the microscope. Check out our coverage of his talk at the 2016 Hackaday SuperConference where he shows us the guts of such favorites as the Z80 and the 555 timer IC.

Ambient Lighting For Baby With The ESP8266

June 7, 2018 by 16 Comments

There are plenty of great reasons to have a child. Perhaps you find the idea of being harshly criticized by a tiny person very appealing, or maybe you enjoy somebody screaming nonsense at you while you’re trying to work on something. But for us, we think the best reason for procreation is getting another excuse to build stuff. It’ll be what, at least two years before a baby can solder or program a microcontroller? Somebody’s going to have to do it for them until then.

To try to help his baby daughter get on a better sleep schedule, [Amir Avni] decided to outfit her room with some “smart” lighting to establish when it’s time for her to wake up. Not only can he and his wife control the time the lights come on to “day” mode, but they can also change the colors. For example, they can switch over to a red glow at night. Despite some learning experience setbacks, the both the parents and the baby are very happy with the final product.

An ESP8266 controls a WS2812 LED strip to provide the adjustable lighting, and a DHT22 sensor was added to the mix to detect the temperature and humidity in the baby’s room. [Amir] used Blynk to quickly throw together a slick mobile application that allows for complete control of the brightness and color of light in the room, as well as provides a readout of the environmental data pulled from the DHT22.

But not everything went according to plan. [Amir] thought he could power the LED strip from the ESP8266 development board by soldering to the 5 V side of its AMS1117 voltage regulator. Which worked fine, until he turned on too many LEDs. Then it pulled too much current through a resistor connected to the regulator, and let all the magic smoke out. An important reminder of what can happen when we ask more of a circuit than what it was designed for.

We’ve covered many awesome projects that were born of a parental need, from feature packed baby monitors to devices seemingly designed to program nostalgia in the little one’s subconscious.

Social Engineering By Railways

June 7, 2018 by 29 Comments

Where do you travel every day? Are there any subtle ploys to manipulate your behavior? Would you recognize them or are they just part of the location? Social engineering sometimes gets a bad rap (or is it rep?) in the mainstream, but the public-facing edge of that sword can keep order as it does in Japanese train stations. They employ a whirlwind of psychological methods to make the stations run like clockwork.

The scope of strategies ranges from the diabolical placement of speakers emitting high-frequency tones to discourage youthful loitering to the considerate installation of blue lights to deter suicides. Not every tactic is as enlightened as suicide prevention, sometimes, just changing the grating departure buzzer to a unique tune for each station goes a long way to relieving anxiety. Who wants to stand next to an anxious traveler who is just getting more and more sweaty? Listen below the break to hear what Tokyo subway tunes sound like.

Maybe you can spot some of these tricks where you live or something similar can ease your own commute. Perhaps the nearest subway has a piano for stairs or a 3D printing cyborg.

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Dive Inside This Old Quartz Watch

June 7, 2018 by 15 Comments

In an age of smartwatches, an analog watch might seem a little old-fashioned. Whether it’s powered by springs or a battery, though, the machinery that spins those little hands is pretty fascinating. Trouble is, taking one apart usually doesn’t reveal too much about their tiny workings, unless you get up close and personal like with this microscopic tour of an analog watch.

This one might seem like a bit of a departure from [electronupdate]’s usual explorations of the dies within various chips, but fear not, for this watch has an electronic movement. The gross anatomy is simple: a battery, a coil for a tiny stepper motor, and the gears needed to rotate the hands. But the driver chip is where the action is. With some beautiful die shots, [electronupdate] walks us through the various areas of the chip – the oscillator, the 15-stage divider cascade that changes the 32.768 kHz signal to a 1 Hz pulse, and a remarkably tiny H-bridge for running the stepper. We found that last section particularly lovely, and always enjoy seeing the structures traced out. There are even some great tips about using GIMP for image processing. Check out the video after the break.

[electronupdate] knows his way around a die, and he’s a great silicon tour guide, whether it’s the guts of an SMT inductor or a Neopixel close-up. He’s also looking to improve his teardowns with a lapping machine, but there are a few problems with that one so far.

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