====== Additional subjects ======

Depending on your needs, the following subjects will also be relevant. Tutorials and other reference materials on these are available at the Arduino website.
  * Communication buses
    * Serial
    * SPI
    * Wire, a.k.a I2C
  * Interrupts
    * External
    * Timers
    * Multiple external
  * Watchdog timers
  * Libraries
    * 7-segment displays
    * LCD displays
    * Switch matrices