Anti-static ESD straps are de rigueur in lab settings for those working with sensitive electronics. They’re a simple protective device, and one that generally doesn’t warrant a second thought. However, [Daniel Bogdanoff] figured they could stand to be a little more fashionable, and set to work on a fancier design.
The first step was to take a look at a regular ESD strap. Typically, they consist of a band that fastens around the wearer’s wrist, with a metal stud for connecting to the earthing lead. The earthing lead contains a high resistance to limit the discharge current to avoid ugly high-energy shorts when wearing the strap.
With a good understanding of the basics, [Daniel] set about modifying a CASIO calculator watch for practice. After soldering a metal stud to the watch case failed, a second attempt with conductive epoxy worked great. The watch could be connected to the earthing strap, and an ESD tester confirmed the device was doing its job.
But unfortunately, permanently modifying the borrowed ROLEX wasn’t an option. Instead, [Daniel] limited his work to a single replacement link which could be inserted into the watch band. Hooked up to an earthing strap, the luxury watch also passed a basic ESD test successfully.
[Daniel] notes that while this is a fun experiment, using properly rated safety equipment is best. Additionally, he points out that the ROLEX is likely to do worse than the CASIO for the simple fact that a metal-banded watch is more likely to cause shorts when working on electronics. Of course, if a watch isn’t your thing, consider a ring instead. Video after the break.
Mechanical watches are triumphs of engineering on a tiny scale. Capable of keeping time by capturing the energy of the user’s own movements, they never need batteries changed. Unfortunately, they quickly lose time when not worn for a few days. To solve that problem, [sblantipodi] built a smart watch winder.
The overall build consists of six individual winder units. Each one has an ESP8266EX D1 Mini microcontroller, hooked up to a 28BYJ48 stepper motor with a ULN2003 motor driver. There’s also an OLED screen for status information. When commanded, the stepper motor turns, rotating a watch case to wind the timepieces. Control is via voice command, thanks to a Google Home Mini and a Raspberry Pi running Home Assistant. Watches can be wound individually, or all together, depending on the command given.
Having an open-source communication device that is independent of any network and works without fees sounds like a hacker’s dream come true. Well, this is exactly what [bobricius]’ is aiming at with his Armawatch and Armachat devices.
Recently, [bobricius] built a LoRa based instant messaging device named Armachat. The gadget is controlled by a SAMD21 MCU with native USB and includes a QWERTY keyboard and an LCD display. Communication is based on an RFM95 LoRa transceiver which can reach a range of up to 2 km under ideal conditions. [bobricius] is a wiz when it comes to PCB design and one thing that makes his projects look so good is how he often uses PCBs as enclosures.
Armachat came in two form factors a large desktop and a smaller pocket version. The new Armawatch is another downsized version that perfectly fits on your arm by using a smaller display and keyboard. [bobricius] also did a lot of work on the firmware which now features a message delivery confirmation and the possibility to automatically resend undelivered messages. Future improvements will include message encryption, a store-and-forward function, and GPS position parsing. [bobricius] is also working on completing his portfolio of communicators with a credit-card-sized version.
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.
High Altitude Balloons (HAB) are a great way to get all kinds of data and shoot great photos and video, but what goes up must come down. Once the equipment has landed, one must track it down. GPS and LoRA, with its long wireless range and ease of use, are invaluable tools in tracking payloads that have returned to Earth. [Dave Akerman] has made handheld receivers to guide him to payloads, but wanted something even smaller; ideally something that could be worn on the wrist.
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.
When you read “Arduino wristwatch”, you fall into the trap of envisioning an Arduino UNO clumsily strapped to someone’s wrist. [Marijo Blažević’s] creation is much more polished than that. A round circuit board holds two surface mount ICs and 12 LEDs. The whole thing looks nice fit snugly inside of a watch body. It isn’t a Rolex, but it does have considerable geek cred without being unwearable in polite company.
One IC is an AVR micro, of course. The other is a DS3231 real time clock with built-in crystal. A CR2032 keeps it all running. The main body, the outer ring, the bottom, and the buttons are 3D printed in PLA. The crystal and the band are the only mechanical parts not printed. The bill of materials shows a 36mm crystal and even provides links for all the parts.
You don’t want to run LEDs all the time because it is bad on the battery. When you press the button once, you get one of the LEDs to light to show the hours. Another press reads the minutes in units of 5 minutes. A third press shows you one of five LEDs to show how many minutes to add. For example, if the time is 9:26 you’d get LED 9 (hours), LED 5 for 25 minutes, and the third press would show LED 1 for 1 extra minute. If either of the minute indicators show 12 o’clock, that indicates zero minutes.
The exciting thing, of course, is that you can program it beyond the code on GitHub. Already it can tell time and display the temperature. You don’t have a lot of I/O, but you ought to be able to get some more options and maybe some flashy LED blinking patterns in if you try.