Esta configuración tiene otras implicaciones. Cuando el Nano se conecta a un PC que funciona con Mac OS X o Linux, se resetea cada vez que se hace la conexión con el software (a través del USB). Durante el siguiente medio segundo más o menos, el bootloader está corriendo en el Nano. Como el bootloader ha sido para programado para ignorar cualquier dato erróneo (cualquier dato que no sea la carga de nuevo código), por lo tanto ignorará los primeros bytes que se reciban justo después de hacer la conexión. Si un sketch cargado en la placa recibe algún tipo de configuración o algún otro tipo de dato importante nada más iniciarse, asegúrate de que el software con el que se comunique, espere al menos un segundo antes de enviar datos para que no sean ignorados por el bootloader.

En vez de necesitar pulsar un botón físico de reset, el Arduino Nano ha sido diseñado de tal manera que permite ser reseteado por el software del PC al que está conectado. Una de las líneas de control de flujo por hardware (DTR) del chip FT232RL está conectada a la línea de reset del ATmega168 o ATmega328 a través de un condensador de 100 nanofaradios. Cuando esta línea se pone a nivel bajo, la linea de reset se mantiene a nivel bajo el suficiente tiempo para causar el reset del chip. El software de Arduino usa esta capacidad para permitir cargar código en el Arduino pulsando simplemente el botón "upload" en el entorno software de Arduino. Esto significa que el tiempo de espera del bootloader es más pequeño, ya que el tiempo en el que se encuentra a nivel bajo el DTR puede ser cordinado bien con el inicio de la carga del código.

Reset Automático (Software)

En vez de necesitar pulsar un botón físico de reset, el Arduino Nano ha sido diseñado de tal manera que permite ser reseteado por el software del PC al que está conectado. Una de las líneas de control de flujo por hardware (DTR) del chip FT232RL está conectada a la línea de reset del ATmega168 o ATmega328 a través de un condensador de 100 nanofaradios. or ATmega328 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.

El ATmega168 o ATmega328 del Arduino Nano vienen preprogramados con un bootloader que te permite subir tu código al Arduino sin la necesidad de un programador externo. Se comunica usando el protocolo STK500 original (referencia, Archivos cabecera C).

También puedes programar el microcontrolador usando un programador ICSP (In-Circuit Serial Programming, Pogramación Serie En-Circuito); visita estasinstrucciones para más detalles.

Programación

La librería SoftwareSerial permite llevar a cabo una comunicación serie usando cualquiera de los pines digitales del Nano.

El ATmega168 y el ATmega328 también soporta comunicación I2C (TWI) y SPI. El software Arduino incluye la librería Wire para simplificar el uso del bus I2C; mira la documentación para más detalles. Para usar la comunicación SPI, por favor mira la hoja de datos del ATmega168 o el ATmega328.

Programción

El Arduino Nano puede ser programado con el software de Arduino (descarga). Selecciona "Arduino Diecimila, Duemilanove, o Nano w/ ATmega168" o "Arduino Duemilanove or Nano w/ ATmega328" de el menú Tools > Board (seleccionando el modelo del microcontrolador en tu placa). Para más detalles, mira la referencia y los tutoriales.

• I²C: Pines 4 (SDA) y 5 (SCL). Soporta comunicación I²C (TWI) usando la librería Wire (documentación en la web Wiring).

Hay algunos otros pines en la placa:

• AREF. Tensión de referencia por las entradas analógicas. Se configura con la función analogReference().

• Reset. Pon esta linea a nivel bajo para resetear el microcontrolador. Normalmente se usa para añadir un botón de reset que mantiene a nivel alto el pin reset mientras no es pulsado.

Mira también el cableado entre los pines Arduino y los puertos del ATmega168.

Comunicación

El Arduino Nao tiene algunos métodos para la comunicación con un PC, otro Arduino, u otros microcontroladores. El ATmega168 y el ATmega328 poseen un módulo UART que funciona con TTL (5V)el cual permite una comunicación vía serie, la cual está disponible usando los pines 0 (RX) y 1 (TX). El chip FTDI FT232RL en la placa hace de puente a través de USB para la comunicación serial y los controladores FTDI (incluidos con el software de Arduino) provee al PC de un puerto com vitual para el software en el PC. El software Arduino incluye un monitor serial que permite visualizar en forma de texto los datos enviados desde y hacia la placa Arduino. Los LEDs RX y TX en la placa parpadearán cuando los datos se estén enviando a través del chip FTDI y la conexión USB con el PC (Pero no para la comunicación directa a través de los pines 0 y 1)

Memoria

El ATmega168 posee 16KB de memoria flash para almacenar el codigo (de los cuales 2KB son usados por el bootloader); el ATmega 328 posee 32KB, (también con 2 KB usados por el bootloader). El Atmega168 posee 1KB de SRAM y 512 bytes de EEPROM (la cual puede ser leida y escrita con la librería EEPROM); el ATmega328 posee 2 KB de SRAM y 1KB de EEPROM.

Entrada y Salida

Cada uno de los 14 pines digitales del Nano puede ser usado como entrada o salida, usando las funciones pinMode(), digitalWrite(), y digitalRead(). Operan a 5 voltios. Cada pin puede proveer o recibir un máximo de 40mA y poseen una resistencia de pull-up (desconectada por defecto) de 20 a 50 kOhms. Además algunos pines poseen funciones especializadas:

• Serial: 0 (RX) y 1 (TX). (RX) usado para recibir y (TX)usado para transmitir datos TTL vía serie. Estos pines están conectados a los pines correspondientes del chip USB-a-TTL de FTDI.

• Interrupciones Externas: pines 2 y 3. Estos pines pueden ser configurados para activar una interrupción por paso a nivel bajo, por flanco de bajada o flanco de subida, o por un cambio de valor. Mira la función attachInterrupt() para más detalles.

• PWM: pines 3, 5, 6, 9, 10, y 11. Proveen de una salida PWM de 8-bits cuando se usa la función analogWrite().

• SPI: pines 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). Estos pines soportan la comunicación SPI, la cual, a pesar de poseer el hardware, no está actualmente soportada en el lenguaje Arduino.

• LED: Pin 13. Existe un LED conectado al pin digital 13. Cuando el pin se encuentra en nivel alto, el LED está encendido, cuando el pin está a nivel bajo, el LED estará apagado.

El Nano posee 8 entradas analógicas, cada unas de ellas provee de 10 bits de resolución (1024 valores diferentes). Por defecto miden entre 5 voltios y masa, sin embargo es posible cambiar el rango superior usando la función analogReference(). También, algunos de estos pines poseen funciones especiales:

Descripción General

El Arduino Nano es una pequeña y completa placa basada en el ATmega328 (Arduino Nano 3.0) o ATmega168 (Arduino Nano 2.x) que se usa conectándola a una protoboard. Tiene más o menos la misma funcionalidad que el Arduino Duemilanove, pero con una presentación diferente. No posee conector para alimentación externa, y funciona con un cable USB Mini-B en vez de el cable estandar. El nano fue diseñado y está siendo producido por Gravitech.

Esquemático y Diseño

Arduino Nano 3.0 (ATmega328): Esquemático, Archivos Eagle.

Arduino Nano 2.3 (ATmega168): manual (pdf), Archivos Eagle. Nota: debido a que la versión gratuita de Eagle no permite trabajar con más de dos capas, y esta versión del Nano posee 4 capas, se ha publicado aquí sin ser enrutado, así los usuarios pueden abrirlo y usarlo en la versión gratuita de Eagle.

Especificaciones:

Alimentación:

El Arduino Nano puede ser alimentado usando el cable USB Mini-B , con una fuente externa no regulada de 6-20V (pin 30), o con una fuente externa regulada de 5V (pin 27). La fuente de alimentación es seleccionada automáticamente a aquella con mayor tensión.

El chip FTDI FT232RL que posee el Nano solo es alimentado si la placa esta siendo alimentada usando el cable USB. como resultado, cuando se utiliza una fuente externa (no USB), la salida de 3.3V (la cual es proporcionada por el chip FTDI) no está disponible y los pines 1 y 0 parpadearán si los pines digitales 0 o 1 están a nivel alto.

The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.0) or ATmega168 (Arduino Nano 2.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one. The Nano was designed and is being produced by Gravitech.

Arduino Nano 3.0 (ATmega328): schematic, Eagle files.

Arduino Nano 2.3 (ATmega168): manual (pdf), Eagle files. Note: since the free version of Eagle does not handle more than 2 layers, and this version of the Nano is 4 layers, it is published here unrouted, so users can open and use it in the free version of Eagle.

The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.

The ATmega168 has 16 KB of flash memory for storing code (of which 2 KB is used for the bootloader); the ATmega328 has 32 KB, (also with 2 KB used for the bootloader). The ATmega168 has 1 KB of SRAM and 512 bytes of EEPROM (which can be read and written with the EEPROM library); the ATmega328 has 2 KB of SRAM and 1 KB of EEPROM.

Communication

The Arduino Nano has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers. The ATmega168 and ATmega328 provide UART TTL (5V) serial communication, which is available on digital pins 0 (RX) and 1 (TX). An FTDI FT232RL on the board channels this serial communication over USB and the FTDI drivers (included with the Arduino software) provide a virtual com port to software on the computer. The Arduino software includes a serial monitor which allows simple textual data to be sent to and from the Arduino board. The RX and TX LEDs on the board will flash when data is being transmitted via the FTDI chip and USB connection to the computer (but not for serial communication on pins 0 and 1).

A SoftwareSerial library allows for serial communication on any of the Nano's digital pins.

The ATmega168 and ATmega328 also support I2C (TWI) and SPI communication. The Arduino software includes a Wire library to simplify use of the I2C bus; see the documentation for details. To use the SPI communication, please see the ATmega168 or ATmega328 datasheet.

The Arduino Nano can be programmed with the Arduino software (download). Select "Arduino Diecimila, Duemilanove, or Nano w/ ATmega168" or "Arduino Duemilanove or Nano w/ ATmega328" from the Tools > Board menu (according to the microcontroller on your board). For details, see the reference and tutorials.

The ATmega168 or ATmega328 on the Arduino Nano comes preburned with a bootloader that allows you to upload new code to it without the use of an external hardware programmer. It communicates using the original STK500 protocol (reference, C header files).

You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header; see these instructions for details.

Rather then requiring a physical press of the reset button before an upload, the Arduino Nano is designed in a way that allows it to be reset by software running on a connected computer. One of the hardware flow control lines (DTR) of the FT232RL is connected to the reset line of the ATmega168 or ATmega328 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.

Arduino Nano Manual (pdf)\\

Nano�s got the breadboard-ability of the Boarduino and the Mini+USB with smaller footprint than either, so users have more breadboard space. It�s got a pin layout that works well with the Mini or the Basic Stamp (TX, RX, ATN, GND on one top, power and ground on the other). It�s a four-layer board with power and ground planes to help provide ICs with sufficient charge during switching and reduce noise (EMC) on high speed switching I/O pins. Ground plane help reduce radiation (EMI). Power plane is low in inductance; therefore any transients that may develop on the power line will be at lower levels.

Eagle files note: since the free version of Eagle does not handle more than 2 layers,and the Nano is currently 4-layer board, Gravitech publishes it here as unrouted, so users can at least open it and use it in the free version of Eagle

• Standard 0.1� spacing DIP (breadboard friendly)

Arduino Nano Manual (pdf)

Arduino Nano Manual (pdf)

Each of the 14 digital pins on the Nano can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:

The Nano has 8 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the analogReference() function. Additionally, some pins have specialized functionality:

The FTDI FT232RL chip on the Nano is only powered if the board is being powered over USB. As a result, when running on external (non-USB) power, the 3.3V output (which is supplied by the FTDI chip) is not available and the RX and TX LEDs will flicker if digital pins 0 or 1 are high.

Memory

The ATmega168 on the Nano has 16 KB of flash memory for storing code (of which 2 KB is used for the bootloader). It has 1 KB of SRAM and 512 bytes of EEPROM (which can be read and written with the EEPROM library).

Input and Output

Each of the 14 digital pins on the Diecimila can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms. In addition, some pins have specialized functions:

• Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the FTDI USB-to-TTL Serial chip.

• External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details.

• PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function.

• SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication, which, although provided by the underlying hardware, is not currently included in the Arduino language.

• LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.

The Diecimila has 6 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and some low-level code. Additionally, some pins have specialized functionality:

• I²C: 4 (SDA) and 5 (SCL). Support I²C (TWI) communication using the Wire library (documentation on the Wiring website).

There are a couple of other pins on the board:

• AREF. Reference voltage for the analog inputs. Used with analogReference().

• Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.

See also the mapping between Arduino pins and ATmega168 ports.

Programming

The Arduino Nano can be programmed with the Arduino software (download). For details, see the reference and tutorials.

The ATmega168 on the Arduino Nano comes preburned with a bootloader that allows you to upload new code to it without the use of an external hardware programmer. It communicates using the original STK500 protocol (reference, C header files).

You can also bypass the bootloader and program the ATmega168 through the ICSP (In-Circuit Serial Programming) header; see these instructions for details.

Automatic (Software) Reset

Rather then requiring a physical press of the reset button before an upload, the Arduino Nano is designed in a way that allows it to be reset by software running on a connected computer. One of the hardware flow control lines (DTR) of the FT232RL is connected to the reset line of the ATmega168 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.

This setup has other implications. When the Nano is connected to either a computer running Mac OS X or Linux, it resets each time a connection is made to it from software (via USB). For the following half-second or so, the bootloader is running on the Nano. While it is programmed to ignore malformed data (i.e. anything besides an upload of new code), it will intercept the first few bytes of data sent to the board after a connection is opened. If a sketch running on the board receives one-time configuration or other data when it first starts, make sure that the software with which it communicates waits a second after opening the connection and before sending this data.

The Arduino Nano can be powered via the mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.

The FTDI FT232RL chip on the Nano is only powered if the board is being powered over USB. As a result, when running on external (non-USB) power, the 3.3V output (which is supplied by the FTDI chip) is not available and the RX and TX LEDs will flicker if digital pins 0 or 1 are high.

The ATmega168 on the Arduino Nano comes preburned with a bootloader that allows you to upload new code to it without the use of an external hardware programmer. It communicates using the original STK500 protocol (reference, C header files).

Programming

Automatic (Software) Reset

Rather then requiring a physical press of the reset button before an upload, the Arduino Nano is designed in a way that allows it to be reset by software running on a connected computer. One of the hardware flow control lines (DTR) of the FT232RL is connected to the reset line of the ATmega168 via a 100 nanofarad capacitor. When this line is asserted (taken low), the reset line drops long enough to reset the chip. The Arduino software uses this capability to allow you to upload code by simply pressing the upload button in the Arduino environment. This means that the bootloader can have a shorter timeout, as the lowering of DTR can be well-coordinated with the start of the upload.

This setup has other implications. When the Nano is connected to either a computer running Mac OS X or Linux, it resets each time a connection is made to it from software (via USB). For the following half-second or so, the bootloader is running on the Nano. While it is programmed to ignore malformed data (i.e. anything besides an upload of new code), it will intercept the first few bytes of data sent to the board after a connection is opened. If a sketch running on the board receives one-time configuration or other data when it first starts, make sure that the software with which it communicates waits a second after opening the connection and before sending this data.

Programm

The Arduino Nano can be programmed with the Arduino software (download). For details, see the reference and tutorials.

The ATmega168 on the Arduino Diecimila comes preburned with a bootloader that allows you to upload new code to it without the use of an external hardware programmer. It communicates using the original STK500 protocol (reference, C header files).

You can also bypass the bootloader and program the ATmega168 through the ICSP (In-Circuit Serial Programming) header; see these instructions for details.

Arduino Nano is a surface mount breadboard embedded version with integrated USB. It is a smallest, complete, and breadboard friendly. The Nano was designed and is being produced by Gravitech.

The Arduino Nano is currently available for pre-order from Gravitech. The boards will ship on June 16th.

Schematic and Design

Attach:ArduinoNanoManual.pdf

Arduino Nano is a surface mount breadboard embedded version with integrated USB. It is a smallest, complete, and breadboard friendly. The Nano was designed by Gravitech.

It has everything that Diecimila has (electrically) with more analog input pins and onboard +5V AREF jumper. Physically, it is missing power jack and power select jumper. Since the Nano is automatically sense and switch to the higher potential source of power, there is no need for the power select jumper.

Arduino Nano

Overview

Arduino Nano is a surface mount breadboard embedded version with integrated USB. It is a smallest, complete, and breadboard friendly. It has everything that Diecimila has (electrically) with more analog input pins and onboard +5V AREF jumper. Physically, it is missing power jack and power select jumper. Since the Nano is automatically sense and switch to the higher potential source of power, there is no need for the power select jumper.

Nano’s got the breadboard-ability of the Boarduino and the Mini+USB with smaller footprint than either, so users have more breadboard space. It’s got a pin layout that works well with the Mini or the Basic Stamp (TX, RX, ATN, GND on one top, power and ground on the other). It’s a four-layer board with power and ground planes to help provide ICs with sufficient charge during switching and reduce noise (EMC) on high speed switching I/O pins. Ground plane help reduce radiation (EMI). Power plane is low in inductance; therefore any transients that may develop on the power line will be at lower levels.

You end up paying less with Nano than Mini and USB combined!

Specifications:

Features:

• Automatic reset during program download
• Power OK blue LED on the bottom
• Green (TX), red (RX) and orange (L) LED
• +5V to AREF jumper
• Auto sensing/switching power input
• Small mini-B USB for programming and serial monitor
• ICSP header for direct program download
• Power OK blue LED on the bottom
• Standard 0.1” spacing DIP (breadboard friendly)
• Manual reset switch

Power:

The Arduino Nano can be powered via the mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.