Control the board from the keyboard

Goal

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

Why it matters

Parsing a text command is already writing a protocol.

Steps

1. 01Serial.begin(9600).
2. 02Test Serial.available(), then read the line.
3. 03Compare the received command and act on it.
4. 04Send back an acknowledgement.

Next tutorials

• Log data as CSV

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

• Remember after power-off (EEPROM)

  Keep a setting even after a restart.

• State machine

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

• Three tasks in parallel

  Blink, measure and display at three different rates.