Project description

F*watch is a fully open electronic watch project featuring an integrated GPS receiver.
The development started at CERN as an after-work project to make a special present for a retiring colleague who likes hiking and timing.
The full design (electronics, mechanics and software) is available under free licenses and the design is exclusively made with free tools.

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Version 1 (click picture to enlarge)


  • Sensors
    • GPS
    • Pressure sensor
    • 3D-accelerometer
    • Compass
    • Ambient light sensor
  • I/O
    • 128x128 pixels LCD with backlight
    • Micro-USB connector, 4 Buttons
    • Buzzer, vibrating motor
    • MicroSD memory slot
  • Various
    • 500 mAh Lithium-ion battery, fuel gauge
    • 4-layer PCB
  • Developed with open KiCad design tool for schematics and PCB
  • Block diagram
  • 3D-printed watch case and buttons
  • Developed with open FreeCAD design tool
  • FreeRTOS operating system
  • Bootloader, drivers, applications
  • Interface to USB host (e.g. download track data, upload firmware)
  • Developed with open gcc compiler

Project documents

F*watch team

  • Project management: Javier
  • Electronics: Matthieu †, Tom, Eva, Thedi, Keith
  • Mechanics: Javier, David, Maciej
  • Software: Andrzej, Orson, Greg, Thedi, Federico, Xavier
  • "Making of" movie: Maciej
  • OHR site management: Erik


Date Event
28-04-2014 Idea for a special present for retiring colleague coined by Javier.
09-05-2014 First meeting. Main features and task forces defined. Aim to have a prototype by September.
16-05-2014 Main components chosen. ComponentSelection.
27-05-2014 Schematics draft ready for review.
03-06-2014 Board almost fully routed.
15-07-2014 Prototype PCB received.
16-07-2014 First board mounted, MCU is accessible with debugger, found a bug in TPS780180300 datasheet.
03-08-2014 Pressure sensor reading and display works.
04-08-2014 3D printed case received. Everything fits.
14-08-2014 Hackathon at CERN.
22-08-2014 Case V3 prototype received, 3D printed in resin.
25-08-2014 First GPS lock!
08-10-2014 F*watch given to the retiring colleague at his goodbye party.
24-10-2014 Designing better housing, with bug fixes and better fastening of the two housing parts.
11-02-2015 Interest shown to improve design with Bluetooth so it can be used as a health monitoring hub.

28 July 2015