LED Clock Strips Time Down To Pulses Of Light

April 15, 2020 by Kristina Panos 7 Comments

Nietzsche said (essentially) that time is a flat circle — we are doomed to repeat history whether we remember it or not. This is a stark and sobering thought for sure, but it’s bound to dissipate the longer you look at [andrei.erdei]’s literal realization of time as a flat circle.

A clock that uses nothing but RGB LEDs to give the time sounds confusing and potentially cluttered, but the result here is quite pleasing and serene. We figure it must be the combination of brighter LEDs to represent 12, 3, 6, and 9, and dimmer LEDs for the rest of the numbers, plus the diffusion scheme. The front plate is smoky acrylic topped with two layers of frosted black window foil.

Inside the printed plastic ring are two adhesive RGB LED strips running on an ESP8266 that ultimately connects to an NTP time server. The strips are two halves of an adhesive 60 LED/meter run that have been stuck together back to back so that the lights are staggered for seamless coverage. This sets up the coolest thing about this clock — the second hand, which is represented by a single pink LED zig-zagging back and forth around the ring. Confused? Watch the short demo after the break and you’ll figure it out in no time.

Now that times are strange, you might be more interested in a straightforward approach to finding out what day it is. The wait is over.

Continue reading “LED Clock Strips Time Down To Pulses Of Light” →

An Adapter To Solve Your ESP-01 Breadboard Woes

April 4, 2020 by Tom Nardi 9 Comments

The ESP-01 launched the ESP8266 revolution back in 2014, and while today you’re far more likely to see somebody use a later version of the chip in a Wemos or NodeMCU development board, there are still tasks the original chip is well suited for. Unfortunately, they can be tricky to use while prototyping because they aren’t very breadboard friendly, but this adapter developed by [Miguel Reis] can help.

Of course, the main issue is the somewhat unusual pinout of the ESP-01. Since it was designed as a daughter board to plug into another device, the header is too tight to fit into a breadboard. The adapter that [Miguel] has come up with widens that up to the point you can put it down the centerline of your breadboard and have plenty of real estate around it.

The second issue is that the ESP-01 is a 3.3 V device, which can be annoying if everything else in the circuit is running on 5 V. To get around this, the adapter includes an SPX3819 regulator and enough capacitors that the somewhat temperamental chip gets the steady low-voltage supply it needs to be happy.

[Miguel] has released the schematics and board files so you can spin up your own copy of the adapter, but they’re also available for around $3 USD from his Tindie store.

Torturing An Instrumented Dive Watch, For Science

July 18, 2019 by Dan Maloney 24 Comments

The Internet is a wild and wooly place where people can spout off about anything with impunity. If you sound like you know what you’re talking about and throw around a few bits of the appropriate jargon, chances are good that somebody out there will believe whatever you’re selling.

Case in point: those that purport that watches rated for 300-meter dives will leak if you wiggle them around too much in the shower. Seems preposterous, but rather than just dismiss the claim, [Kristopher Marciniak] chose to disprove it with a tiny wireless pressure sensor stuffed into a dive watch case. The idea occurred to him when his gaze fell across an ESP-01 module next to a watch on his bench. Figuring the two needed to get together, he ordered a BMP280 pressure sensor board, tiny enough itself to fit anywhere. Teamed up with a small LiPo pack, everything was stuffed into an Invicta dive watch case. A little code was added to log the temperature and pressure and transmit the results over WiFi, and [Kristopher] was off to torture test his setup.

The first interesting result is how exquisitely sensitive the sensor is, and how much a small change in temperature can affect the pressure inside the case. The watch took a simulated dive to 70 meters in a pressure vessel, which only increased the internal pressure marginally, and took a skin-flaying shower with a 2300-PSI (16 MPa) pressure washer, also with minimal impact. The video below shows the results, but the take-home message is that a dive watch that leaks in the shower isn’t much of a dive watch.

Hats off to [Kristopher] for doing the work here. We always love citizen science efforts such as this, whether it’s hardware-free radio astronomy or sampling whale snot with a drone.

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LED Matrix Becomes Fun Tetris Clock

June 27, 2019 by Lewin Day 1 Comment

Sometimes a project is borne simply out of the fact that some interesting parts have been left sitting around too long. Of course, this is as good a reason to build as any other, and can often lead to some interesting results. [Jorj Bauer]’s Tetris Display is one such project.

The project started because [Jorj] had an 8 x 32 WS2812 LED array laying about, and it was high time it got turned into something cool. The resulting display has several features, making it a welcome piece around the home. It can act as a clock, with automatic compensation for daylight savings and brightness control depending on the time of day. It can also serve as a text scroller, and of course, the party piece – it can play Tetris. It all runs on an ESP-01, with a second device acting as a remote to control the game.

Rather than simply being another LED matrix project, [Jorj] put a little flair into things. A font was developed that allowed the time to be displayed in a pixel font composed entirely of Tetris pieces (or tetrominos). This allows the time to be displayed by pieces dropping from the top of the display. The Tetris implementation is solid, too – implementing the proper Super Rotation System that professionals would expect.

[Jorj] reports that this build was inspired by an earlier Tetris Clock featured in these very pages. It’s a tidy piece that we’re sure is a great addition to the mantlepiece. Video after the break. Continue reading “LED Matrix Becomes Fun Tetris Clock” →

RGB Word Clock Doesn’t Skimp On The Features

March 9, 2019 by Tom Nardi 5 Comments

Like most pieces of technology, word clocks seem to be getting better and better every year. As hackers get their hands on better microcontrollers and more capable LED controllers, these builds not only look more polished, but get improved features and functions. Luckily for us, the rise of these advanced modular components means they’re getting easier to build too. For an example of these parallel traits, look no further than VERBIS by [Andrei Erdei].

This colorful word clock is powered by an ESP8266, a 8×8 RGB LED matrix, and a WS2812 RGB LED controller module. [Andrei] used the diminutive ESP-01 which can plug right into the LED controller, and just needs a 3.3 VDC regulator board to complete the very compact electronics package.

To keep the LEDs from interfering with each other, [Andrei] has designed a 3D printed grid which fits over the matrix board. On top of that goes a piece of paper that has the letters printed on it. He mentions that he was able to get good results printing this “stencil” out on an inkjet printer by simply running the same piece of paper through a few times; picking up more black ink each time it went through. Judging by the sharp characters seen in the video after the break, the trick worked well.

With his hardware put together, [Andrei] turned his attention to the software. We really think the project shines here, as his clock not only supports NTP for automatically setting the time over the Internet, but offers a full web interface to control various functions such as the LED colors. You can even change the NTP server and network configuration right from the UI, which is a nice touch compared to just hard coding the values into the code. Even if you don’t use the same hardware, the open source control software is definitely something you should look into if you’re building your own word clock.

We recently covered another easy to build word clock that used an LED matrix and not a whole lot else, but it was quite tiny. This build is a much more reasonable size for a desk, but you’ll probably need to break out the laser cutter if you want to get much bigger.

Continue reading “RGB Word Clock Doesn’t Skimp On The Features” →

Junk Bin Self Balancing Bot With ESP8266

July 5, 2018 by Tom Nardi 10 Comments

As we all know, sometimes the projects we plan simply never materialize. You have an idea, maybe even buy some of the parts you need, and then…nothing. Maybe you changed your mind, or maybe the idea was never that good to begin with. In any event, time marches on, the parts pile up, and the ideas come and go. Such is the life of the hacker.

[Andrius Mikonis] writes in to tell us how his graveyard of abandoned projects ended up providing exactly what he needed to embark on a project he’s been fascinated with for years: the two-wheel self balancing robot. He started with a motor and wheel set that was originally intended to be part of a rover, added an accelerometer, and tied the whole thing together with an ESP-01 he had lying around. The final result certainly looks the part, and goes to show that projects don’t always need to be 1000 hour labors of love to accomplish their goals.

The construction of this little bot is simple in the extreme. A piece of plywood makes up the primary structure, with the wheels glued to the bottom and the electronics taking up residence in the top. It’s powered by two lithium battery cells that were salvaged out of an old laptop, with a DC-DC buck converter to provide a stable 3.3 VDC for the ESP-01 and MPU6050 accelerometer. To control the motors themselves, [Andrius] is using a cheap L293 controller that he found on eBay.

For interactive control, [Andrius] is making use of the ESP’s Wi-Fi to provide a web-based interface. This lets you control the bot from essentially any device that has a browser, rather than having to use a dedicated hardware transmitter.

Self-balancing robots of various levels of complexity are a relatively common project in the hacker world. There’s just something magical about the way they scoot around, seeming to defy gravity.

ESP-01 Bridges The Gap Between IR And WiFi

February 20, 2018 by Tom Nardi 29 Comments

[Emilio Ficara] dropped us a line recently about his efforts to drag his television and receiver kicking and screaming into the modern era. His TV is old enough that it needs an external tuner, which means it requires two separate remotes to properly channel surf. He wanted to simplify the situation, and figured that while he was at it he might as well make the whole thing controllable over WiFi.

To begin the project, [Emilio] had to capture the IR signals from the two remotes he wanted to emulate. He put together a quick little IR receiver out of parts he had in the junk bin which would connect up to his computer’s microphone port. He then used an open source IR protocol analyzer to capture the codes and decode them into hex values.

As a proof of concept he came up with a little device that combines an ESP-01 with an ATmega88. The ESP-01 runs a minimal web server that receives hex codes as URL query strings. These hex codes are then interpreted by the ATmega88 and sent out over the IR LED. [Emilio] notes that driving the IR LED directly off of the ATmega pin results in fairly low range of around one meter, but that’s good enough for his purposes. If you want to drive the IR LED with more power, you’ll need to add a transistor to do the switching.

Passing the hex code 0x0408 to turn off the TV

Now that he can decode the signals from his original remotes and transmit them over WiFi via his bridge device, he has all the groundwork he needs to come up with a streamlined home entertainment controller. A native application for his smartphone or perhaps a minimal web interface is the last piece of the puzzle.

This project reminds us of a similar attempt at controlling legacy IR devices from a smartphone via Bluetooth. If you’re looking for more information about wrangling IR signals from your microcontroller, this primer from 2013 is still a great look at the subject.