Remember after power-off (EEPROM)

Goal

Keep a setting even after a restart.

Why it matters

RAM is wiped at power-off: EEPROM keeps user settings.

Steps

1. 01Include <EEPROM.h>.
2. 02Read the stored value at start-up.
3. 03Write with EEPROM.update() (writes only when the value changes).
4. 04Print the restored value.

Next tutorials

• Control the board from the keyboard

  Switch the LED on/off with the “on” and “off” commands.

• Log data as CSV

  Produce “time;value” lines usable in a spreadsheet.

• State machine

  Structure a traffic light into explicit states (GREEN, AMBER, RED).

• Three tasks in parallel

  Blink, measure and display at three different rates.