- Goal of the project : By clicking four buttons in a certain sequence, the lock will be locked or unlocked indicating by two leds. If it is unlocked, the blue led will light up; if it is locked, the red led will light up.
- Core components : 4 buttons, 4 x 10K ohms resistors, red and blue leds, 2 x 220 ohms resistors, breadboard, arduino board, jumper wires
- How it works : If you press buttons from 1 to 4, the blue led will light up and fade out in a while. Otherwise the red led will light up.
- Problems encountered : the button is unstable sometimes.
