Smartwatch built from scratch, both hardware, software and mechanics. Built on the Zephyr™ Project RTOS, hence the name ZSWatch - Zephyr Smartwatch.

The project includes all parts necessary to build your own DIY Smartwatch: hardware, software, and mechanical parts.

About the project

This is a project I have been working on almost 1.5 years. The goal of the project was to prepare my life as a dad, people said I'd have no time for hobby projects when you are a parent. I didn't fully trust them and said to myself there must be one hour now and then free for hobby projects.

The idea was to create a project that I could work on after our daughter arrived. I wanted a good foundation that I could keep building on whenever I had an hour of free time. This is where the idea of a Smart Watch came up. The infinite amount of features you can add, both simple and advanced. For example, being able to maybe build a small app in an hour or two is really nice. I don't need to figure out what to code, I can just implement a feature some other smartwatches already have.

It's 100% Open Source

I'm pretty sure I can say with confidence that this project is 100% open source.

The KiCad project files and .step for casing are available, and there is not a single binary blob in the software!

ZSWatch uses the Zephyr Project SDK and its fully Open Source Bluetooth Controller. This means everything from the lowest level radio register up to the ZSWatch application is all Open Source, and I think this is quite unique!

The future

The project is rapidly improving with new contributors. New features are already in the works with the next PCB revision, such as USB, a new fuel gauge for better battery handling, and a MEMS Microphone that gives new possibilities such as voice recognition and ML. We are trying to be backwards compatible, which means people who have already a ZSWatch can upgrade just by swapping out the PCB!

Hardware features

• nRF5340 BLE chip (u-blox NORA-B10 module).
• 128 MHz Dual core.
• 512 KB RAM.
• 1 MB Flash.
• 240x240 round display with touch screen.
• IMU Bosch BMI270, with this one it's possible to do many fancy things such as navigation using gestures and the typical smartwatch wake-up by moving the arm, so the display is viewable.
• Bosch BME688 Environmental sensor with AI.
• Bosch BMP581 High performance pressure sensor accuracy in units of ~20cm's.
• ST LIS2MDLTR Magnetometer.
• Renesas AT25SL128A 16 MB external flash.
• Broadcom APDS-9306-065 Light Sensor for automatic brightness control.
• Option to not mount some sensors to save BOM cost.

Software Features

• Bluetooth LE communications with GadgetBridge Android app.
• Also support Bluetooth Direction Finding, so the watch can act as a tag and is trackable using any u-blox AoA antenna board
• Pop-up notifications
• Step counting
• Gestures
• Air Quality
• And much more ...

Multiple Watchfaces showing

• Standard stuff as time, date, battery
• Weather
• Step count
• Number unread notifications
• Environmental data
• ...

Application picker and app concept

• Setting menu system, with easy extendability
• Music control app
• Settings app
• Compass app
• etc.

The user can choose from a few different watch faces.

Dock

In order to make the project as accessible for everyone ZSWatch also have a dock, this dock includes a J-LINK OB debugger which means everyone get access to proper debugging capabilities for a good price!

Manufacturing

PCBWay manufactured all the main parts: PCBs, Assembley, CNC:ed Stainless Steel casing.

Left brass, right black anodized aluminium from PCBWay.

Find out more

Head over to our GitHub to get all the details: https://github.com/jakkra/ZSWatch