141 Digital padlock

141 : Digital padlock

Design renderSelect Project123456789ONSW2
  • Author: Jean THOMAS
  • Description: A 4-digit electronic padlock
  • GitHub repository
  • Clock: 100 Hz

How it works

Each buttons press is detected by a rising edge detector, and each button press is decoded into a binary code. That binary code is stored in a shift-register which is continuously checked against a reference value ('the padlock code').

How to test

Connect a clock generator to the clock input, connect all four buttons with a debounce circuit - the buttons should act as active high.

External hardware

Four push buttons, cabled as active high with hardware debounce circuitry.

Picture

IO

#InputOutput
0clock
1Button A
2Button B
3Button C
4Button D
5
6Button press detected
7Code valid