A Watch With One Needle, and the Patience to Read It
A Raspberry Pi inside, a lab voltmeter outside, and a single needle that swings to tell you the hour. The cost of one needle is patience. Maybe that is the feature.
Sahko, the maker behind last year's flexible-PCB amber-LED smartwatch, has published a new wristwatch on GitHub. It is a single moving needle that sweeps across an analog voltmeter dial. Hackaday picked it up on May 23.
A Raspberry Pi Pico drives a digital-to-analog converter, which feeds voltage to a simple analog coil meter, the kind you would find inside old lab gear. The needle's position is the time. Press a button on the case and the meter cycles through hours, minutes and seconds, the current month, the day of the week. Only one value can be on screen at a time. That is the cost of having one needle. The dial backer is a custom PCB rather than printed paper, which gives it the hard, slightly green-flecked finish of working test equipment. The aluminum case is CNC-milled from a solid block and bead-blasted to a soft matte.
Most wearables optimize for legibility. They show more, faster, and ask less of you. This goes the other direction. The needle has to swing across a scale. You have to wait a beat. You have to actually look. Maybe the watch worth wearing is the one that asks something of you to read it.