A YouTube Subscriber Counter With A Tetris Twist

When it comes to YouTube subscriber counters, there’s not much wiggle room for creativity. Sure, you can go with Nixies or even more exotic displays, but in the end a counter is just a bunch of numbers.

But [Brian Lough] found a way to jazz things up with this Tetris-playing YouTube sub counter. For those of you not familiar with [Brian]’s channel, it’s really worth a watch. He tends toward long live-stream videos where he works on one project for a marathon session, and there’s a lot to learn from peeking over his virtual shoulder. This project stems from an earlier video, posted after the break, which itself was a condensation of several sessions hacking with the RGB matrix that would form the display for this project. He’s become enamored of the cheap and readily-available 64×32 pixel RGB displays, and borrowing an idea from Mc Lighting author [toblum], he decided that digits being assembled from falling Tetris blocks would be a nice twist. [Brian] had to port the Tetris-ifying code to Arduino before getting the ESP8266 to do the work of getting the subs and updating the display. We think the display looks great, and the fact that the library is open and available means that you too can add Tetris animations to your projects.

None of this is to say that more traditional sub counters can’t be cool too. From a minimalist display to keeping track of all your social media, good designs are everywhere. And adding a solid copper play button is a nice touch too.

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Buttery Smooth Fades with the Power of HSV

In firmware-land we usually refer to colors using RGB. This is intuitively pleasing with a little background on color theory and an understanding of how multicolor LEDs work. Most of the colorful LEDs we are use not actually a single diode. They are red, green, and blue diodes shoved together in tight quarters. (Though interestingly very high end LEDs use even more colors than that, but that’s a topic for another article.) When all three light up at once the emitted light munges together into a single color which your brain perceives. Appropriately the schematic symbol for an RGB LED without an onboard controller typically depicts three discrete LEDs all together. So it’s clear why representing an RGB LED in code as three individual values {R, G, B} makes sense. But binding our representation of color in firmware to the physical system we accidentally limit ourselves.

The inside of an RGB LED

Last time we talked about color spaces, we learned about different ways to represent color spatially. The key insight was that these models called color spaces could be used to represent the same colors using different groups of values. And in fact that the grouped values themselves could be used to describe multidimensional spacial coordinates. But that post was missing the punchline. “So what if you can represent colors in a cylinder!” I hear you cry. “Why do I care?” Well, it turns out that using colorspace can make some common firmware tasks easier. Follow on to learn how!

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Definitely-Not-Neopixel Rings, From Scratch!

The WS2812 addressable LED is a marvellous component. Any colour light you want, all under the control of your favourite microcontroller, and daisy-chainable to your heart’s content. Unsurprisingly they have become extremely popular, and can be found in a significant number of the project s you might read about in these pages.

A host of products have appeared containing WS2812s, among which Adafruit’s Neopixel rings are one of the more memorable. But they aren’t quite as cheap as [Hyperlon] would like, so the ever-resourceful hacker has created an alternative for the constructor of more limited means. It takes the form of a circular PCB that apes the Adafruit original, and it claims to deliver a Bill of Materials cost that is 85% cheaper.

In reality the Instructables tutorial linked above is as much about how to create a PCB and surface-mount solder as it is specific to the pixel ring, and many readers will already be familiar with those procedures. But we won’t rest until everyone out there has tried their hands at spinning their own PCB project, and this certainly proves that such an endeavour is not out of reach. Whether or not you pay for the convenience of the original or follow this lead is your own choice.

The real thing has been in so many projects it’s difficult to pick just one to link to. This Christmas tree is rather nice.

Joe Grand is Hiding Data in Plain Sight: LEDs that Look Solid but Send a Message

Thursday night was a real treat. I got to see both Joe Grand and Kitty Yeung at the HDDG meetup, each speaking about their recent work.

Joe walked us through the OpticSpy, his newest hardware product that had its genesis in some of the earliest days of data leakage. Remember those lights on old modems that would blink when data is being transmitted or received? The easiest way to design this circuit is to tie the status LEDs directly to the RX and TX lines of a serial port, but it turns out that’s broadcasting your data out to anyone with a camera. You can’t see the light blinking so fast with your eyes of course, but with the right gear you most certainly could read out the ones and zeros. Joe built an homage to that time using a BPW21R photodiode.

Transmitting data over light is something that television manufacturers have been doing for decades, too. How do they work in a room full of light sources? They filter for the carrier signal (usually 38 kHz). But what if you’re interested in finding an arbitrary signal? Joe’s bag of tricks does it without the carrier and across a large spectrum. It feels a bit like magic, but even if you know how it works, his explanation of the hardware is worth a watch!

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Ambient Lighting for Baby with the ESP8266

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.

Illuminated Bread for a Cookie Cutter World

Just in case you thought your eyes were playing tricks on you, we’d like to confirm right from the start that what you are looking at is a loaf of bread with internal LED lighting. Why has this bread been internally lit? We can’t really say. But what we can do is pass on the fascinating process that took an unremarkable piece of stale bread and turned it into an exceptional piece of stale bread.

As demonstrated by [The Maker Monster], working with stale bread is basically like working with wood. Wood that you can dip in soup, granted, but wood nonetheless. The process of electrifying the loaf starts with cutting it down the length on a bandsaw, and then hollowing it out with a rotary tool. This creates a fairly translucent shell that’s basically just crust.

You’re probably wondering how you keep a bread-light from getting moldy, and thankfully [The Maker Monster] does address that issue. The bread shell is completely coated with shellac, which creates a hard protective layer that will not only prevent decay but should give it some added strength. In the video it looks like only one coat is applied, but if we had to guess, a few coats would be necessary to really seal it up. Coating it with epoxy wouldn’t be a terrible idea either.

While the shellac dries on the bread, he gets to work on the lighted base (bet you never imagined you’d read a sentence like that), which is really just a sanded piece of wood with a standard LED strip stuck too it. It’s very understated, but of course the glowing loaf really draws the eye anyway. All that’s left is to glue the bread down to the base, and proudly display your creation at your next dinner party.

We can’t say that an electric ciabatta is in the cards for Hackaday HQ; but we know that baking good bread is a science in itself, and turning the failed attempts into works of art does have a certain appeal to it.

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Supercapacitors In A Servo: The “Forever” Flashlight

The principle is well understood: use a motor in reverse and you get a generator. Using this bit of knowledge back in 2001 is what kick-started [Ted Yapo]’s Hackaday Prize entry. At the time, [Ted] was searching for a small flashlight for astronomy, but didn’t like dealing with dead batteries. He quickly cobbled together a makeshift solution out of some supercapacitors and a servo-as-a-generator, hacked for continuous rotation.

A testament to the supercapacitors, 17 years later it’s still going strong – leading [Ted] to document the project and also improve it. The original circuit was as simple as a servo, protection diode, some supercapacitors, and a LED with accompanying resistor; but now greater things are afoot.

A DC-DC boost converter enables constant power through the LED, regardless of the capacitor voltage. This is achieved by connecting the feedback pin of an MCP1624 switcher to an INA199 current-shunt monitor. The MCP1624 kicks in at 0.65V and stays active down to 0.35V. This is all possible due to the supercapacitors, which happily keep increasing current as voltage drops – all the way to 0.35V. Batteries are less ideal in this situation, as their internal resistance increases as voltage drops, as well as increasing with age.

When testing the new design, [Ted] found that the gears on his servos kept stripping when he was using them to charge capacitors. Though at first he attributed it to the fact that the gears were plastic, he realized that his original prototype from 2001 had been plastic as well. Eventually, he discovered the cause: modern supercapacitors are too good! The ones he’d been using in 2001 were significantly less advanced and had a much higher ESR, limiting the charging current. The only solution is to use metal gear servos

Want to read more about boost converter design? We have the pros and cons of microcontrollers for boost converters, or this neat Nixie driver for USB power.