These two functions must be present. setup() contains the code that the microcontroller runs once upon being powered, the loop() function contains the code that loops tightly forever.
– Arduino-specific libraries are added and a main() function is added as part of compilation, you may not have your own main() function – remember to think of setup() and loop()
– Function prototypes are added, which means you do not need to declare a function before first using it, it can be declared later or elsewhere.
– After the above translations, the Arduino language is C++.
How to use it / background
This is a microcontroller, ATmega328P.
It costs between $3.50 (quantity 1) down to $1.50 or less (in quantity of a few thousand) and there are cheaper and more expensive microchips. It runs at 20 Mhz, with a few kBytes of memory.
When loaded with an Arduino program, whenever powered it will run it forever in a tight loop. It has no ‘operating system’ per se. The above microcontroller is the heart of the most common Arduino development board, the Uno:
How to use it / background
This is a microcontroller, ATmega328P.
It costs between $3.50 (quantity 1) down to $1.50 or less (in quantity of a few thousand) and there are cheaper and more expensive microchips. It runs at 20 Mhz, with a few kBytes of memory.
When loaded with an Arduino program, whenever powered it will run it forever in a tight loop. It has no ‘operating system’ per se. The above microcontroller is the heart of the most common Arduino development board, the Uno:
For more detail: 35-second Arduino language reference