The USB (Universal Serial Bus) is a standard that defines the cables, connectors and used a bus to connect, communicate, computers, peripherals and electronic devices protocols Transmission Rates Low speed (USB 1.0). Transfer rate up to 1.5 Mbit/s (188 kB/s) used in keyboard, mouse ... transfer rate up to 12 Mbit/s (1.5 MB/s) High Speed ??(USB 2.0): Rate transferencia up to 480 Mbit/s (60 MB/s) SuperSpeed ??(USB 3.0) transfer rate up to 4.8 Gbit/s (600 MB/s) Connector Types 1 - USB type A (4 pin) 2. - USB type B (4 pin) 3 - Mini A (5-pin) 4 - Mini B (5-pin) 5 - Micro A (5-pin) 6 - Micro B (5-pin)

or horizontal. The micro USB with five pins, which pins identification (ID) Micro AB USB connectors special work. AB connectors with pin ID can allow the device to function as a connector A or B to standard USB technology. This gives the new smart phones and other devices the option to act as either a single storage device or as provi

The mini USB connectors are smaller than their standard counterparts and have USB fifth pin. The fifth pin is known as the pin ID and is typically not used in mini USB connectors. It was designed to allow later improved USB technology. The mini USB connectors have a cycle life of at least 5000 connections and disconnections, which accommodates the mobile nature of the devices that are designed to interact. The standard USB connectors are generally used with devices that are stationary and not disconnected often.

RS-232 (Recommended Standard 232, also known as EIA/TIA RS-232C) is an interface that designates a standard for the exchange of a series of binary data between a DTE (Data Terminal Equipment) and DCE (Data Communication Equipment , Data Communication Equipment), although there are others in which the RS-232 interface is also used. An equivalent definition published by the ITU is called V.24. The RS-232 is a connectorDB-25 type (25-pin), although it is normal to find the version of 9-pin (DE-9, or popularly also called DB-9), cheaper and even extended to certain types of peripherals (such as serial mouse PC).

USB 3.0 is the second major revision of the standard Universal Serial Bus (USB) connectivity for computing. USB 3.0 has transmission speeds of up to 5 Gbit/s, which is 10 times faster than USB 2.0 (480 Mbit/s). Connector Types 1 - USB type A plug 2 - 3 USB type A female - USB type B 4 - Micro USB B

USB-C reversible USB version called USB cables USB Type C Type C or USB reversible. The important thing is this type of USB is that it has top and bottom. So you may save the blows that are given involuntarily to connect the connector upside down. It is also characterized in that when connected will make an audible "click". The USB-C or reversible USB cables can reach 10 Gbps and support USB 3.0, 3.1Use is estimated up to 10,000 applications and has some measures 8.4mm x 2.6mm is also compatible with USB 3.1 and USB indicate creators

PWM technically be the pulse-width modulation (also known as PWM stands for pulse-width modulation) of a signal or energy source. It is a technique in which the duty cycle of a periodic signal (a sine or a square, for example) is modified, either for transmitting information through a communications channel or to control the amount of power that is sent to a load. Pair

Arduino is defined as a combined system between hardware and software, which allows users with or without programming knowledge to create projects from scratch. Thanks to its low cost and its wide range of accessories, it has become one of the most appreciated devices by the creative community or called makers (creators).

Within the Arduino range we can find different devices, which will allow us to easily create projects that perform different functions. Its open source GNU free access is essential in the maker community, which allows its creator to develop almost any prototype he can think of.

Arduino was created with the aim of reducing and lowering the material costs needed by interactive design students from Ivrea, Italy, since the devices they used previously were very expensive. This new Arduino project reduced the cost of the material each student needed and eventually became a commercial product as we know it today.

These small plates consist of a SRAM memory, with its own flash storage system (EEPROM), microcontrollers and a microprocessor, currently we can find different processors for the most current models, such as processors:

- 8-bit Atmel AVR
- 32-bit ARM Cortex-M0+
- 32-bit ARM CortexM3
- Intel Quark (x86) 32-bit

Arduino has an open source programming software called the Arduino IDE, with which anyone can create the basis of a new project. Both software and hardware are compatible with Windows, MacOS, and Linux operating systems. Its programming only requires a USB connection to the PC and the free programming software.

Among the different devices we can find the main Arduino board, the nerve center of any project, among which we can find:

- Arduino Uno R3
- Arduino Leonardo
-Arduino 101
- Arduino Explore
-Arduino Zero
- Arduino Mega 2560
-Arduino Due
-ArduinoMicro
- Arduino Nano
- Arduino MXR 2 UNO Adapter
- Arduino MKR Zero
- Arduino Yun
- Arduino Ethernet among others



In order to expand its functionality, we have a wide range of shields or modules that allow you to expand its functionality, such as screens, Wi-Fi modules, etc. these can be attached to the Arduino board itself, thus allowing it to read inputs and send data outputs. Among some shields we can find:

- Xbee wireless modules
- USB ports
- Sensors
- Breadboard
- Card readers
- WiFi connection
- Motors or servos
- Ethernet connection
- GPS module
- GSM module
- RS232 module
- Relays
- LCD screens
- Sound and DMX

Among some examples that we can create with Arduino and its external components we can find clocks, scales, alarms, automated irrigation systems, a battery tester, control of mechanical arms and much more.

Thanks to its large community of makers, we can find hundreds of projects to carry out on the net, ideal for delving into the world of electronics and programming, whether at an educational, professional or domestic level.