Pseudonymous maker “Valentine” is engaged on a Bluetooth Low Power smartwatch, emphasis on the “low vitality” — concentrating on a 10-year runtime on a single cost, with the potential so as to add a compact photo voltaic panel to energy the machine without end.
“Growing a sensible watch from scratch could be an incredible studying expertise to advance my information of low-power, self-contained powered gadgets. Therefore, we study watches, smartwatches, and wearables typically by designing one,” Valentine explains of the challenge. “This isn’t a industrial effort. I doubt that we’re making something new per se, nevertheless, we try to advance the artwork loads additional than others into the low-power area.”
This flex PCB represents a pre-alpha design for a smartwatch concentrating on a decade-long runtime. (📷: Valentine)
Valentine has some massive asks for his smartwatch design, even earlier than you get into the need for a decade-long runtime. It must be maintenance-free, he says, without having to open the machine, and it shouldn’t have any buttons or different shifting elements. It must be powerful sufficient to “crush rocks,” function within the depths of the ocean, and will embody on-board sensors, sync to atomic clocks, and even present a compass — although, on the time of writing, the challenge was specializing in core watch performance, together with alarms.
“Testing the ability consumption with a 200mA[h] battery, BLE at -40db. Estimated lifetime of that setup with none energy tuning could be about 5,000 hours (~200 days),” Valentine writes of preliminary testing with a “pre-alpha” board. “To offer you an concept how arduous that is, it takes a group of extremely certified folks working for months to get to this stage. I did it over a number of weekends in my bed room listening to Gert van Hoef.”
The preliminary design is constructed round a Sharp reminiscence show, providing a sunlight-readable monochrome panel which pulls much less energy than rival liquid-crystal show applied sciences, linked to a Nordic Semi nRF52 offering the controlling logic and Bluetooth Low Power (BLE) connectivity to a smartphone and a five-parts-per-million temperature-compensated crystal oscillator (TCXO) for timekeeping.
The design targets as low an influence draw as potential, in a design which depends on BLE connectivity for configuration and management. (📷: Valentine)
Initially, Valentine discovered the antenna design inflicting points with reaching a low sufficient energy draw — till Nordic supplied to optimize the design in-house. “I used to be extraordinarily impressed by the extent of customer support,” Valentine writes. “I am going to take them up the provide as soon as I finalize my case design.”
Valentine is not solely fascinated with what is going on into the watch, although, however about what the skin will seem like — displaying off a chunky physique which protects the show behind a mineral crystal glass panel and encloses the electronics in a completely-sealed chrome steel physique. Additional experiments have proven that the machine attracts so little energy it may run from a photo voltaic cell — although the maker is engaged on constructing the self-contained model first earlier than doubtlessly investigating including photo voltaic charging to the design.
Extra info on the work-in-progress challenge is out there on Valentine’s Hackaday.io web page; no design recordsdata or supply code have but been launched.