A few days ago [Andrew] contacted us to offer his help for the design of the mooltipass project case. While introducing himself, he casually mentioned his OLED watch that you can see above.
The watch is based on the low-power MSP430F microcontroller from Texas Instruments. It can consume as little as 1.5uA while maintaining a real-time clock and monitoring interrupts. It also uses ferroelectric RAM, which doesn’t need any power to retain its memory contents. That means there’s no need to set the time again if you remove the CR2016 battery that powers the watch.
[Andrew] chose an 0.96″ OLED display that only consumes up to 7mA. He also included an accelerometer that allows him to interact with the watch through its single and double tap detecting feature. He modeled his PCB using EagleCAD and the whole assembly using Sketchup. Most of the components were soldered in his reflow (toaster) oven. The final result is a mere 8.8mm thick and looks very professional in our opinion.
Our mouth is still agape after digging through [Tom’s] watchmaking blog. This gentleman spent several years designing and machining his own mechanical wristwatch. A dozen years ago or so [Tom] answered an ad for an apprentice watchmaker. He worked on watches and came across a book that detailed how timepieces are made. He was told that no-one does it like that anymore, which only fed his curiosity. What he came up with is, to his knowledge, the first timepiece every made in Australia.
It’s no secret that we have a thing for clocks. But we feature digital timepieces almost exclusively. We’ve love mechanical watches too but don’t see them as hobby projects very frequently. After looking at what goes into the mechanism it’s not hard to see why.
[Tom] was faced with a variety of challenges along the way. One of the biggest was having to come up with tools that would let him perform the precise milling work necessary to achieve success. You’ll want to read through his movement design and manufacture posts. He laid out the plan in CAD, but ended up using some hacked together milling tools to get the job done.
Here’s a wristwatch concept we haven’t seen before. Instead of trying to sandwich everything inside of a case it uses a stack of PCBs as the body of the watch.
[Mats Engstrom] wrote in to tip us off about his build. The design goes with LEDs which is nothing new. But unlike previous offerings [Mats] didn’t go with one LED for each minute. When the touch sensor in the middle of the watch is activated the twelve LEDs on the face will let you know the hour and the nearest five minutes. A video of this is embedded after the break.
The design uses three different circuit boards. The bottom board is the largest and provides slots through which the wrist bands can connect. It also serves as one of the two battery connectors. The second PCB is a spacer with a cutout for the coin cell that powers the device. The top board is where all the magic happens. It’s dual sided to host the LEDs and touch senor, with the PIC microcontroller and support circuitry on the other side.
Continue reading “Wristwatch made of sandwiched PCBs”
We love looking at roll-your-own wristwatch projects. Getting a project small enough to carry around on your wrist is a real challenge. But we think the OTM-02 wristwatch really hit the form factor right on the mark.
OTM stands for Open source Time Machine. It’s the work of [Hairy Kiwi] and he managed to bring the guts of the watch in at a thickness between 6.5 and 7mm. That includes the LCD, PCB, piezo diaphragm, and the battery. The PCB itself is a four-layer board built on 1mm thick substrate. It’s running an EFM32 (ARM) microcontroller which comes with hardware USB support. The little door sitting open on the side of the 3D printed enclosure provides access to the micro USB connector which can be used to charge the 150 mAh battery inside. That may not sound like much juice, but if you set the display to show minutes only [Hairy] calculates a battery life approaching 175 days. If you just have to have the seconds displayed you can expect about two weeks between charges.
Like the name says, this project is Open Source.
There are 2 types of people in the world; those who know binary, those who don’t, and those who know ternary. [Emanuele] thought a binary wristwatch is the pinnacle of nerd and set out to build his own. The resulting binary clock not only screams nerd as intended, but is also a functional time piece, as well.
The idea of a binary wristwatch came to [Emanuele] while he was working with PICs at school. Not wanting to let that knowledge go to waste, he used a PIC16F628 microcontroller for this build. There are four LEDs for the hours and six LEDs for the minutes, each attached to a separate microcontroller pin for easy programming.
To keep time, [Emanuele] kept the PIC in sleep mode most of the time, only waking it up when a an internal timer’s register overflows. The watch spends most of its time sleeping, sipping power from a coin cell battery with a battery life that should last weeks, at least.
The entire circuit is tucked away in a PVC enclosure with a wonderful rainbow ribbon cable band. We’re not so sure about how that feels against the skin all day, but it does exude the nerd cred [Emanuele] was looking for.
This slmwtch lives up to its name. When the LCD screen is folded back onto the PCB the entire thing comes in at just 2.35mm. That’s including a coin-cell battery not shown above. Wow!
Part of what makes this possible is the specialized PCB design. [Anders] didn’t want to add more thickness than the screen and battery so he make a cutout in the PCB design to accept each component. In this image it’s easiest to see on the two SMD resistor in the upper left. They’re held in a void by the two solder connections. Admittedly this is not going to be a mass-production friendly design. And we have concerts about the long-term stability of suspending components by their leads. But as a one-off it’s fantastic! See for yourself in the video after the break.
The control for the watch uses two touch sensitive pads on the back of the PCB. There is no backlight for the display which can be a problem when trying to read the time while outdoors. We wonder if an ePaper display with similar dimensions is available?
Continue reading “Super slim wristwatch build”
Wow, we’re seeing all kinds of good stuff from NYC Resistor today. [Caleb] found this link to [Hudson’s] early work on a geeky wristwatch. It is based around an HDSP-2112 eight-digit alpha-numeric display. Each digit is a 5×7 array of LEDs, but the look of it really reminds us of [Woz’s] Nixie Wristwatch. The nice thing about using a display like this one is it’s much easier to drive and the power requirements don’t really call for special consideration either.
The display happens to be nearly the same footprint as the Teensy 2.0. In fact, the display is a bit longer. That makes it a perfect backpack, bringing everything necessary to drive the display. Check out the video after the break to see it scrolling the time as words, and displaying numbers.
This needs to have an RTC and portable power source before you can wear it around. But the proof is there. Perhaps [Hudson] will spin his own board with a uC that includes RTC capability and a charging circuit for a tiny Lithium cell.
Continue reading “The beginnings of a geeky wristwatch”