Arduino is a platform that allows us to program microcontrollers quickly and quite easily as there are many code samples (libraries) for most applications.

Arduino is a board consisting of a common microcontroller (Atmel AVR example) which has inputs, outputs, for connection to peripherals such as led, motors, switches, relays, etc. buttons.

This whole philosophy helps to implement automation.

Essentially what makes special the arduino and widespread is what the code is written in wiring language (language c / c ++ with libraries written in c / c ++) which is kept in a specially designed environment to be loaded directly apps (Arduino software) and communicate the arduino boards, some are listed below.

There are several versions Arduino differing capabilities and in size like the arduino nano, the arduino mini pro, arduino uno, arduino mega, arduino yun etc.


We refer a few applications that we can create with arduino.


  • To connect led and illuminate sequentially with delay or in any combination desired as we set by the program.

  • To connect button when the push, microcontroller (arduino) to run process that we have set.


  • For example, when push button 1, microcontroller turn on the third led, when we press the second button, microcontroller turn on all the leds we have connected to board etc.
  • To connect relay for controlling electrical loads such as lamps, etc. motors. Previously to implement automation we used relay (electromagnetic switches, ie a coil when triggered attracts or repels switches) for the power circuit and the control circuit too.

Control circuit is how to switch on and off loads (time delays, order of activation - deactivation etc.) Process complicated, time consuming, with high costs and without possibility of customizing and modifying operation in the future. The implementation of the relay, time delays, multiple relay switches have replaced with PLC (programmable logic controller), which essentially comes to circuit units of microcontrollers with opto isolated inputs for analog sensors, signal outputs and outputs with relay (for digital loads) or even analog outputs (triac, transistor, etc.) for regulating engine speed, lamp brightness variation (dimming) etc. The process is implemented in a PLC may be embodied in a arduino but PLC used in the industry because there many protocols (modbus, profibus etc.) to which are connected and communicate with peripherals and supervisory systems (scada). From the above description we conclude that the PLC, the microcontrollers, the arduino in this case and in general embedded systems have replaced relay, time delays, and many auxiliary switches in any automation control circuit. 

Power circuit comprises the load (light, motor, etc.) which is connected with switch of relay and coil will be triggered by the control circuit.

Finally an automation consists of the control circuit is now being implemented with "embedded" systems which communicate with the power circuit consisting of relays for digital loads "open - closed" or triacs, mosfets, thyristors for analog output setting etc.


  • To connect screen that displays messages that we have defined, or to show the process in which the microcontroller is programmed. eg. "turn on the first led", "just press the button 1", "the second led will turn on in five seconds" etc..


  • To connect sensors to record the brightness, temperature, moisture from the environment etc.


  • To connect RTC (real time clock) module that provides time and date information with registered calendar with built in backup battery, with backup battery ensures uninterrupted operation of the unit when is interrupted power supply.


  • To connect a memory card module that stores the data recorded by the sensors.Display Example: "Date: 02.15.2015, time: 13:45, Brightness: 90%, temperature: 20oC, Humidity: 60%).

 Above description called registration information system (data logger).


  • To connect a network drive ethernet module, wifi module even implement server to remotely monitor process (telemetry) and to control (remote control).


  • To combine all of the above (limited) examples of a project.