Arduino. Programmable AVR microcontroller from ATMEL. Example programming.

The Arduino uno in version R3. 

Arduino is a small, relatively, capability, computer board with memory for program and data, digital inputs, analog inputs and outputs to 5 volt DC, or 3,3 volt DC for newer models. It has the advantage of low price compared to what it offers.

Most models have a simulation of analog output at specific pins, using the technique of PWM (Pulse-width modulation), are the outputs on the board with the symbol of the wave as the alternating current.

The Arduino due has real analog outputs.

Connected to computer and programmed via simple USB cable .

The processor of arduino is from Atmel (Advanced Technology for MEmory and Logic) which has established the Greek George Perlegas 1984 in the USA Before the foundation of working in Intel.
The AVR is a RISC architecture construction (Reduced Instruction Set Computer) processors provide high speed of execution, usually in a circle of the clock.

On the main board Arduino adapted various boards called Shields and add extras such possibility: Monitors, gsm card, ethernet, bluetooth, relay etc. The each of them has its own commands (routines). Libraries.

There is a small PLC, as the LOGO! based on Arduino, is compatible with it and called controllino. http://www.controllino.cc/

Programming is done in an integrated development environment (IDE Integrated Development Environment) based on C language and is freely available from the site http://www.arduino.cc/.

These programs are called sketch because the environment is based on the Processing language aimed at graphic designers.

The Arduino programming environment with an example.

With pinMode we set the corresponding pin as input or output because the Arduino pins can be both, of course not at the same time.

The program runs continuously until you cut the current flow rate, it is set in routine loop () from baseline ({) to the final bracket (}).

Right from the "//" put comments for program documentation