The case, the boards, the software – all this he designed and made himself. And then also published materials for creation in open access.
In early May, Imgur user under the nickname Samsonmarch shared his experience of creating the simplest “smart” watches from scratch. The author admitted that he worked as an engineer in an American firm for the design and manufacture of various devices. Therefore, he had experience and access to some details.
The result of the work was a device that holds a charge for more than a week and shows time and notifications. The journalist Andrey Brodetsky paid attention to the detailed description of the creation of watches .
According to the developer with Imgur, he had the idea from 2018. First of all, he developed the design of the clock in the free Fusion 360 program. Samsonmarch immediately settled on a circular shape: “From a technical point of view, square ones are better, they can contain more information. But I’m not a fan of such displays, which are now everywhere. I didn’t need another phone or computer on my wrist. ”
The shape of the case depended on the chosen shape of the screen; in the lower part, the engineer left room for the battery and other necessary details. Screen settings – TFT LCD with a resolution of 240×240.
The author of the material printed out two parts of the case on his own 3D printer for $ 160. The material consisted of 70% of plastic and 30% of wood dust, because of what resembled real wood. The main disadvantage of this material is that after printing on the body, there are fibers that spoil the appearance. Their Samsonmarch cleaned with sandpaper, and then varnished the material.
The next step was to create an electronic “filling” of the watch. The engineer divided the work stages into four blocks.
- Power supply – battery and the ability to charge the device;
- A block of sensors – “what explains the clock, what is happening around”;
- The drive unit is “the part of the clock that interacts with the outside world”;
- A Bluetooth unit is everything that connects a watch with a smartphone.
The result was a printed circuit board. The engineer completed it and built it into the printed case, then connected it to the screen. The main part of the “smart” watch is ready.
But without software, all this would remain just a model of “smart” watches. Samsonmarch wrote most of the code, adding a few functions to the device. According to him, the operating system is written on the basis of freeRTOS.
- Compatibility with iOS using Bluetooth, including the ability to send notifications from a smartphone to the clock;
- Development of screen animations;
- Adjust the accelerometer so that the watch unlocks itself when raising the wrist to view the time;
- Customize wallpaper, display pictures, numbers and letters on the screen;
- The function of “contacts”, which recognizes the sender of the message and displays his avatar on the screen.
According to the watch maker, they work for about a week without recharging. Imgur user also made a charger himself. The work took him more than two months – the development began in January 2019 and ended in March. The entire project cost him about $ 50.
Imgur user stressed that he does not intend to monetize his device. As proof, he published all the code and drawings for the printer in the public domain, so that everyone could make a similar watch if they wanted to