Interrupt is a programming concept found in microcontroler and regular computers alike. External event can interrupt running code and be handled immediatelly. Sleep mode can almost turn off the device, saving power. In this course you'll learn how to use both these techniques on Arduino boards.
The following courses are freely available, after registration and login.
Arduino boards with the ATmega32U4 chip can emulate any USB device, including keyboard, mouse or gamepad. This can be used for both good and evil. In this course you'll learn how to make your own custom keyboard.
It's a staple of 80's action movies: bomb in acrylic casing with glowing red display. We won't teach you how to make the bomb, but you can learn how to make beautiful NTP synchronized clock in acrylic casing with ESP8266 and a bit of code.