While many of us now use our phones to keep track of what time of day it is, it’s still nice to have a watch that shows you — at literally the flick of your wrist — this important information. If you’d like to make one that’s all your own, plus ups your geek cred, creator moononournation shows you how with his recent project.
The build starts out with a “core” assembly, accessing the different dev board options available, how to keep it accurate, the triggering method, and of course, the display. He settled on the Pro Micro board, as it uses an ATmega32U4 microcontroller for control and USB communication without a power hungry FTDI chip.
It also comes in a 3.3V version, allowing it to easily be used with a 3.7V LiPo. Display-wise, he chose a 240 x 240 pixel ST7789 LCD, and an RTC module keeps time. Finally, a pair of vibration sensors wakes the prototype up from sleep mode.
Part two outlines how the device was stuffed into a watch housing. It’s an impressive feat of miniaturization, with the Pro board arranged beside a tiny LiPo. The RTC and another small (1 mAh) battery are soldered on toward the bottom of the board. The LCD screen is then placed on top to conceal the components, and everything is crammed into a nice printed case with a wrist strap. Unfortunately, the double vibration sensor setup couldn’t be fit in the case, so hopefully moononournation will be able to come up with an acceptable alternative at some point in the future!
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Author: Jeremy S. Cook