Built a PCB for the watch. Yes it is hand soldered. Calling it Aurora.

The PCB contains the NRF52840,  MX25L3233FZBI NOR flash, LSM6DSOX IMU, and connectors for vibration motor and HR sensor ( which i may get to later). Getting the right components which have minimal height was a challenge, especially due to the global chip shortage. I worked with what I could get my hands on. The top of the PCB has pads where a spring connector would connect for power and USB. The 5 holes on the right are pads for programming.

Soldering the NRF52 package was a pain but finally got it done using a hot plate and patience. I didn't want to use a BLE module this time with everything done for you. I learned a lot about RF design and antennas by using just the chip.