Toggle button (debounced)

Goal

One press turns on, the next turns off — with no contact bounce.

Why it matters

A mechanical contact bounces for ~10 ms: without filtering, one press counts as ten.

Steps

1. 01Store the previous button state (lastState).
2. 02Detect the falling edge HIGH → LOW.
3. 03Ignore changes happening less than 50 ms after the previous one (millis()).
4. 04Toggle a boolean ledOn and apply it.

Next tutorials

• Read a push button

  Light the LED only while the button is pressed.

• Read a potentiometer

  Print the analog value of A0 on the serial monitor.

• Convert to volts (map & float)

  Turn the ADC's 0–1023 into a 0.00–5.00 V reading.

• Light sensor (LDR)

  Turn the LED on automatically when the room gets dark.