---
active: true
tags: project
created: 2026-06-08 19:27
---
## Goal

Build a time clock with:

- Hangs on the wall
- LCD backlit clock
- Fingerprint reader
- Keypad for PIN and UI
- Simple clock-in/clock-out interface
- Way to generate a help request
- System connects to a backend database that stores the timecard data
- PoE for power
- Built in speaker for sound effects
## Tasks

- [x] Order parts ➕ 2026-06-08 ✅ 2026-07-11
- [x] Print two halves of the case (rev 1) ➕ 2026-07-09 ✅ 2026-07-09
- [x] Adjust case halves ➕ 2026-07-09 ✅ 2026-07-09
- [x] Print rev 2 of cases ➕ 2026-07-09 ✅ 2026-07-09
- [x] Install inserts into the case halves ➕ 2026-07-09 ✅ 2026-07-10

## Notes

The FPM10A (or DY50) is a highly popular optical fingerprint sensor that communicates over a TTL serial interface. It features an internal DSP chip that handles rendering, calculation, and feature-finding, making it exceptionally easy to use with an Arduino for smart locks and access control projects.
### Wiring Connections

The FPM10A usually comes with a 6-pin connector, but you only need to use the 4 pins designated for power and serial communication.

- **Red Wire (VCC)**: Connect to Arduino **5V**
- **Black/Green Wire (GND)**: Connect to Arduino **GND**
- **Green Wire (TXD)**: Connect to Arduino Digital Pin **2**
- **White/Yellow Wire (RXD)**: Connect to Arduino Digital Pin **3**
## References

- [FPM10A Fingerprint Sensor](https://doc.grablo.co/en/docs/user-manuals/i-o-device/as608-fpm10a-fingerprint-sensor/#3.)
- [`rppal uart`](https://docs.rs/rppal/latest/rppal/uart/index.html)
- [`Grow-r502-a_fingerprint_sensor`](https://crates.io/crates/Grow-r502-a_fingerprint_sensor)
- [`bell ding 1.wav`](freesound.org/people/5ro4/sounds/611113/)