What could you do with a dual-core 240 MHz ESP32 that supports Arduino-style programming, with 16 MB of flash, 8 MB of PSRAM, and 520 k of RAM? Oh, let’s throw in a touchscreen, an accelerometer, Wifi, and Bluetooth. Besides that, it fits on your wrist and can show the time? That’s the proposition behind Lilygo T Watch 2020. If it sounds like a smartwatch, it is. At around $25 –and you can snag the hardware from a few different places — it is not only cheaper than the latest flagship smartwatch, but it is also infinitely more hackable.
OK, so the screen is only 1.54″, but then again, it is a watch. If Arduino isn’t your thing, you can use anything else that supports the ESP32 like Micropython or even Scratch. There are variants that have LoRA and GPS, at slightly higher prices. You can also find ones with heart rate monitors and other features.
Binary clocks are a great way to confuse your non-technical peers when they ask the time from you — not that knowing about the binary system would magically give you quick reading skills of one yourself. In that case, they’re quite a nice little puzzle, and even a good alternative to the quarantine clocks we’ve come across a lot recently, since you can simply choose not to bother trying to figure out the exact time. But with enough training, you’ll eventually get the hang of it, and you might be in need for a new temporal challenge. Well, time to level up then, and the Cryptic Wall Clock built by [tomatoskins] will definitely keep you busy with that.
Diagram of the clock showing 08:44:47
If you happen to be familiar with the Mengenlehreuhr in Berlin, this one here uses the same concept, but is built in a circular shape, giving it more of a natural clock look. And if you’re not familiar with the Mengenlehreuhr (a word so nice, we had to write it twice), the way [tomatoskins]’ clock works is to construct the time in 24-hour format by lighting up several sections in the five LED rings surrounding a center dot.
Starting from the innermost ring, each section of the rings represent intervals of 5h, 1h, 5m, 1m, and 2s, with 4, 4, 11, 4, and 29 sections per ring respectively. The center dot simply adds an additional second. The idea is to multiply each lit up section by the interval it represents, and add the time together that way. So if each ring has exactly one section lit up, the time is 06:06:02 without the dot, and 06:06:03 with the dot — but you will find some more elaborate examples in his detailed write-up.
As awesome as space is, we’re inspired by the amount of Earth-saving reuse going on in this project. The actual time-telling is coming from a recycled wristwatch movement. [Artistikk] cut a bigger set of hands for it out of a plastic container, and used the lid from another container for the clock’s body.
The launch inquiries are handled by an ESP8266, which uses a Blynk app and some IFTTT magic to get notified whenever NASA yeets an astronaut into space. Then the ESP generates random RGB values and sends them to a single RGB LED. The clock body is small enough that a single LED is bright enough to light up all the parts that aren’t blacked out with thick paper. In case you’re wondering, the pattern around the edge isn’t random, it’s Morse code for ‘sky’, but you probably already knew that, right? Make a dash past the break to take the tour.
Here at Hackaday, we love a good clock project. And if it’s an artistically executed freeform sculpture, even better. But tell us that it’s also a new spin on a classic project from two decades ago, and we’re over the moon for it. Case in point: [Paul Gallagher’s] beautiful recreation of an LED clock riffing on one originally made as a weekend project in early 2000.
Wait, wait. Hold up.
*Ted unclips the microphone from his lapel and stands up from his chair*
OK, dear reader, if you’ll allow me, we’re going to do this one a little differently. Normally I’m supposed to write in the voice of Hackaday, but this project has personal meaning for me, so I’d like to break the rules a bit. You see, the original clock project was mine — one I did over a weekend a long time ago, as evidenced by the “2/13/2000” date on the PCB — and I was quite honored that [Paul] would choose my project as inspiration.
Original Clock Project dated 2/13/2000
When, on the 20th anniversary of creating this clock, I posted a Twitter thread to commemorate the event, [Paul] picked up the ball and ran with it. You can see the original Twitter thread here. Pictures of the home-etched single-sided board were all he needed to reverse-engineer the relatively simple design, and then re-create it with style.
The design uses a PIC16F84 microcontroller. This was one of the first microcontrollers to really become popular with hobbyists, the key features being the serial programming algorithm which allowed easy homebrew programmers, and the FLASH memory. If I recall correctly, my original programmer ran off a PC’s parallel port. I probably have it in a box somewhere. Each of the 12 LEDs is driven through a separate resistor from individual GPIO lines, while a 32.768 kHz crystal serves as the timebase. Finally, two buttons allow you to set the hours and minutes.
How do you represent three separate hands on such a display? In this case, each hand blinks at a different rate. The hour LED is solid, and the second LED blinks faster than the minute one. You can check it out in [Paul’s] video after the break, and admire the beautiful simplicity of his layout.
Since he was able to re-create the circuit exactly, [Paul] was able to drop-in the original assembly code that runs the clock. True-to-form, Microchip still manufactures the PIC16F84, and their latest tools have no problem with such legacy code — it just works.
Sundials, one of humanity’s oldest ways of telling time, are typically permanent installations. The very good reason for this is that telling time by the sun with any degree of accuracy requires two-dimensional calibration — once for cardinal direction, and the other for local latitude.
Switch it on, set it down, and the sundial spins around on a continuous-rotation servo until the HMC5883L compass module finds the north-south orientation. Then the GPS module determines the latitude, and a 180° servo pans the plate until it finds the ideal position. Everything is controlled with an Arduino Nano and runs on a 9V battery, although we’d love to see it run on solar power someday. Or would that be flying too close to the sun? Check out how fast this thing calibrates itself in the short demo after the break.
For many people, these last few weeks have been quite an adjustment. When the normal routine of work or school is suddenly removed, it’s not unusual for your internal clock to get knocked out of alignment. It might have started with struggling to figure out if it was time for lunch or dinner, but now it’s gotten to the point that even the days are starting to blur together. If it takes more than a few seconds for you to remember whether or not it’s a weekday, [whosdadog] has come up with something that might help you get back on track.
Rather than showing the time of day, this 3D printed clock tells you where you are in the current week. Each day at midnight, the hand will advance to the center of the next day. If you wanted, a slight reworking of the gearing and servo arrangement on the rear of the device could allow it to sweep smoothly through each day. That would give you an idea of your progress through each 24 hour period, but then again, if you don’t even know if it’s morning or night you might be too far gone for this build anyway.
The clock’s servo is driven by a Wemos D1 Mini ESP8266 development board, which naturally means it has access to WiFi and can set itself to the current time (or at least, day) with NTP. All you’ve got to do is put your network information into the Sketch before flashing it to the ESP, and you’re good to go.
Nothing says tech addict quite like the wearing of a binary watch — and we say that as tech addicts ourselves. However, many of the homebrew binary watches we’ve seen don’t just look nerdy because they are showing the time in binary. They are nerdy because it looks like someone strapped an Arduino to their wrist. Not so with [APTechnologies] “Ultimate Binary Watch.”
While creating a binary clock is not amazing in of itself, we were highly impressed with the look of this watch. The 3D printed case and the use of surface mount LEDs makes a great looking package. We wondered how it would look with a colored plastic cover like you’d find over an old LED clock. On the other hand, the exposed LEDs do have a certain charm to them.
