Arduino keypad door lock: 4×4 keypad, servo bolt and LCD
Open in the lab ▸Make my own copy
Type 2580 and # and a servo pulls the bolt open for 5 s; three wrong codes lock the keypad for 30 s. The keypad is scanned by hand (one row low at a time, columns read with pull-ups), so you can see how a matrix keypad works without a library. Open it and press Run: the sketch is inside the board (click the board, then Code). Every part, pin and resistor matches what you would build on a real breadboard; the guided build of the same name has the test sheet and hidden faults.
What is on the bench
7 parts, 19 wires, with a sketch (the program runs in the lab). Boards: Arduino Uno R3.
| Arduino Uno R3 | 1 |
|---|---|
| USB charger / port | 1 |
| 4×4 keypad | 1 |
| Hobby servo | 1 |
| Active buzzer | 1 |
| I2C LCD | 1 |
Put it on your page
The project runs live inside the frame: readers can press buttons, turn knobs and read the meters.
<iframe src="https://zencircuitlab.com/embed/zclckeylock" width="100%" height="560" style="border:1px solid #2f363a;border-radius:10px" loading="lazy" title="Arduino keypad door lock: 4×4 keypad, servo bolt and LCD on Zen Circuit Lab"></iframe>
Link
https://zencircuitlab.com/p/zclckeylock
Published by its author under the lab's community terms: it may be opened, copied and changed by anyone. Simulation results are for learning; check a real build against the parts' datasheets.