Embedded software program engineer Jakob Krantz created a smartwatch design as an open sourced {hardware} and software program undertaking referred to as ZSWatch. The total title is Zephyr Smartwatch, which runs the Zephyr real-time working system
ZSWatch Round PCB (📷: jakkra, GitHub)
Inside ZSWatch’s 3D-printed case is a four-layer round PCB measuring 36mm. On that PCB is an u-blox ANNA-B402 module that incorporates a Nordic nRF52833 BLE SoC. The sensor package deal contains an accelerometer, pulse oximeter, and coronary heart price monitor. As well as, there’s a haptic vibration motor, battery administration circuit, an eight-megabyte flash, and three push buttons for navigation.
Beneath the PCB is a 220 mAh LiPo battery. And above the PCB is a 1.28-inch 240×240 IPS TFT round show. A sapphire crystal glass protects the TFT (and every part beneath it.)
Inside ZSWatch (📷: jakkra, GitHub)
ZSWatch connects to a dock by means of pogo pins. The connections present energy and get away the SWD pins for the nRF SoC.
Presently, the watch’s face shows the kind of info you’d anticipate in a smartwatch. For instance, it exhibits the present time, date, battery life, climate, and step counter. Whereas Krantz did embrace the heartbeat oximeter and heart-rate sensor, its firmware nonetheless must be totally carried out. For instance, ZSWatch samples knowledge from the guts price sensor however doesn’t calculate something with it.
ZSWatch face and step counting (📷: jakkra, GitHub)
Assist with Android telephones comes by means of an app referred to as GadgetBridge. For compatibility, ZSWatch emulates an already-supported smartwatch. With this connection, ZSWatch and GadgetBridge work collectively for actions like notifications.
Krantz open sourced each the software program (firmware) and {hardware} design for ZSWatch. Nonetheless, the advice is to attend for model 2.0 earlier than constructing one. The newer model fixes just a few recognized points. For instance, the brand new model makes use of a u-blox NORA-B10 with the nRF5340 SoC, which fixes a BLE pairing difficulty. It additionally provides a contact display screen!
Go to the ZSWatch GitHub repo to obtain the mechanical CAD information, KiCad design, and app code. You can too watch the undertaking to see when model 2.0 turns into obtainable.
