This repository contains the KiCad project and design files for a custom low-power digital alarm clock based on the Renesas RL78/L12 microcontroller.
The firmware repo: https://github.com/poh0/tickbox_firmware
Measured Total 1.9 uA idle current (LCD ON + RTC ticking),
The clock is idle most of the time and when it's not, current is still well under a milliamp.
Thus it is reasonable to expect battery life of up to 8 years on a CR2032
- Microcontroller: Renesas RL78/L12 (R5F10RLA - 64-pin LFQFP)
- Display: 4-Digit 7-Segment static LCD
- Power Source: Any Coin Cell (3.0V). Tested on CR2025
- User Interface:
- 3x Tactile Buttons (SET TIME/ALARM, INC, SNOOZE/BACKLIGHT)
- 1x Piezo Buzzer (4kHz Passive)
- Clock Source:
- Main: High-Speed On-Chip Oscillator (HOCO)
- Sub: External 32.768 kHz Crystal (for deep sleep RTC+LCD+TIMERS)
For specifics about pin configurations and internal peripherals, refer to the firmware repo.
I'll add bom later
