Smart Safety Watch Schematic Design

We are looking for an experienced embedded hardware engineer to design the complete electrical schematic for a low-power Smart Safety Watch in KiCad.

The device is MCU-based, not Android-based.

Main hardware blocks:
- Nordic nRF5340 MCU
- LTE Cat-1 bis modem with GNSS
- Low-power accelerometer / IMU
- Li-ion battery charger
- Battery fuel gauge
- 500–600 mAh Li-ion battery
- Buck / buck-boost power regulation
- Modem power switch
- BLE antenna
- LTE / GNSS antenna interfaces
- Small display connector
- SOS / control buttons
- Vibration motor / buzzer
- USB / charging interface
- SWD programming/debug interface
- ESD and protection circuits

Main functions:
- Step counting
- Fall / jerk detection
- Manual SOS
- GNSS location
- LTE / SMS emergency alerts
- BLE mobile app connection
- OTA firmware update
- Low-power operation

Required deliverables:
- Complete editable KiCad schematic
- KiCad source files
- Pin mapping
- Preliminary BOM with manufacturer part numbers
- Power-tree diagram
- Interface list
- ERC-clean schematic
- Notes for RF, power and high-current sections
- Datasheet references for major ICs

This stage is SCHEMATIC ONLY. Do not start PCB layout until written approval is provided.

The selected engineer must first submit a block diagram and proposed power architecture for approval.

Do not substitute major components without written approval.

Please apply only if you have experience with Nordic nRF52/nRF53, LTE/GNSS, battery-powered wearable devices, RF design and KiCad.