Hourglass

Hourglass is a custom PCB watch designed in KiCAD 7.0, to be funded by the Hack Club OnBoard grant, which allocates $100 for high schoolers to design and build their own custom PCBs.

Features

• Accelerometer & Magnetometer for detecting orientation and movement
• 60 individual LEDs for displaying minutes & seconds
• RTC for high-precision timekeeping
• Programmable user buttons
• Revision A:
  • FIDO2 Authentication token
  • USB-C interface
• Revision B:
  • Cheap manufacturing cost

Revisions

Revision A: Working design iteration

Status: ✔️ (COMPLETE)

Revision A is the original design, based on the Atmel ATMega32u4 microcontroller. It features a RTC and 9DoF magnetometer-accelerometer to detect orientation, magnetic field strength and more to act as both a device for keeping time and sense when the wearer has raised the watchface to observe. In addition, a USB-C port can allow for interfacing directly to the Mega for uploading code and other functions.

Revision B: Cost-effective design

Status: ✔️ (COMPLETE)

Revision B is a easier, more affordable option. I'm working on this primarily because revision A is simply too expensive with all peripherals added in to have assembled via JLC's PCBA. It swaps the ATMega32 with an RP2040, the 9DoF magnetometer with split magnetometer & accelerometer ICs, and forgoes the rear battery slot alltogether. The caveat with this is you'll need to wire a battery to the device yourself, but comes at a tremendous discount with the requirement for dual-sided PCB assembly forgone.