The Arduino Fio is a microcontroller board based on the ATmega328P ([[http://www.atmel.com/dyn/resources/prod_documents/8271.pdf | datasheet]]) runs at 3.3V and 8 MHz. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 8 analog inputs, an on-board resonator, a reset button, and holes for mounting pin headers. It has connections for a Lithium Polymer battery and includes a charge circuit over USB. An XBee socket is available on the bottom of the board.
The Arduino Fio is intended for wireless applications. The user can upload sketches with an a FTDI cable or Sparkfun breakout board. Additionally, by using a modified USB-to-XBee adaptor such as XBee Explorer USB, the user can upload sketches wirelessly. The board comes without pre-mounted headers, allowing the use of various types of connectors or direct soldering of wires.
The Arduino Fio was designed by Shigeru Kobayashi and SparkFun Electronics, and manufactured by SparkFun Electronics.
!!!Schematic & Reference Design
EAGLE files: [[Attach:arduino-pro-mini-reference-design.zip | arduino-fio-reference-design.zip]]
Schematic: [[Attach:Arduino-Fio-schematic.pdf | Arduino-Fio-schematic.pdf]]
||Operating Voltage ||3.3V||
||Input Voltage ||3.35 -12 V||
||Input Voltage for Charge ||3.7 - 7 V||
||Digital I/O Pins ||14 (of which 6 provide PWM output)||
||Analog Input Pins ||8||
||DC Current per I/O Pin ||40 mA||
||Flash Memory ||32 KB (of which 2 KB used by bootloader)||
||SRAM ||2 KB||
||EEPROM ||1 KB||
||Clock Speed ||8 MHz||
The Arduino Fio can be powered with an FTDI cable or breakout board connected to its six pin headers (as marked on the bottom side), or with a regulated 3.3V supply on the 3V3 pin or a Lithium Polymer battery on the BAT pins.
The power pins are as follows:
* '''BAT.''' For supplying a Lithium Polymer battery to the board.
* '''3V3.''' The regulated 3.3 volt supply pins.
* '''GND.''' Ground pins.
The ATmega328P has 32 KB of flash memory for storing code (of which 2 KB is used for the bootloader). It has 2 KB of SRAM and 1 KB of EEPROM (which can be read and written with the [[http://www.arduino.cc/en/Reference/EEPROM | EEPROM library]]).
!!!Input and Output
Each of the 14 digital pins on the Fio can be used as an input or output, using [[Reference/PinMode | pinMode()]], [[Reference/DigitalWrite | digitalWrite()]], and [[Reference/DigitalRead | digitalRead()]] functions. They operate at 3.3 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: RXI (D0) and TXO (D1).''' Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the DOUT and DIN pins of the XBee modem socket.
* '''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 [[Reference/AttachInterrupt | attachInterrupt()]] function for details.
* '''PWM: 3, 5, 6, 9, 10, and 11.''' Provide 8-bit PWM output with the [[Reference/AnalogWrite | 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 Fio has 8 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). The analog inputs measure from ground to Vcc. Additionally, some pins have specialized functionality:
* '''I'^2^'C: 4 (SDA) and 5 (SCL).''' Support I'^2^'C (TWI) communication using the [[Reference/Wire | Wire library]].
There are couple of another pins on the board:
* '''AREF.''' Reference voltage for the analog inputs. Used with [[Reference/AnalogReference|analogReference()]].
* '''DTR.''' Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.
There are also 8 unsoldered holes on the board:
* '''BAT +''' and '''BAT -.''' To be connected to a battery. Typically used when you don't want to connect a battery to the battery connector.
* '''CHG 5V''' and ''CHG -.''' To be connected to charging terminals. Typically used to add an external connector for charging.
* '''SW.''' Connected to the power switch on the board. Typically used to add an external power switch.
* '''CTS.''' Connected to the #CTS/DIO7 pin of the XBee socket. Typically used to do sleep control for a XBee modem.
* '''DTR.''' Connected to the #DTR/SLEEP_RQ/DI8 pin of the XBee socket. Typically used to do sleep control for a XBee modem.
See also the [[Hacking/PinMapping168 | mapping between Arduino pins and ATmega328P ports]].
The Arduino Fio has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers. The ATmega328P provides UART TTL serial communication, which is available on digital pins 0 (RX) and 1 (TX). The Arduino software includes a serial monitor which allows simple textual data to be sent to and from the Arduino Fio board via an external serial connection. We recommend using an FTDI Basic or FTDI cable. The on board mini-USB connector is only used for charging and does not allow for serial communication.
A [[http://www.arduino.cc/en/Reference/SoftwareSerial | SoftwareSerial library]] allows for serial communication on any of the Fio's digital pins.
The ATmega328P also supports I2C (TWI) and SPI communication. The Arduino software includes a Wire library to simplify use of the I2C bus; see the [[Reference/Wire | reference]] for details. To use the SPI communication, please see the ATmega328P datasheet.
The Arduino Fio can be programmed with the Arduino software ([[Main/Software | download]]). For details, see the [[Reference/HomePage | reference]] and [[Tutorial/HomePage | tutorials]].
The ATmega328P on the Arduino Fio comes preburned with a [[Tutorial/Bootloader | 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 ([[http://www.atmel.com/dyn/resources/prod_documents/doc2525.pdf | reference]], [[http://www.atmel.com/dyn/resources/prod_documents/avr061.zip | C header files]]).
You can also bypass the bootloader and program the ATmega328P with an external programmer; see [[Hacking/MiniBootloader | these instructions]] for details.
You can upload sketches wirelessly. Make sure you are using a Series 1 (not 2 or 2.5) XBee module if you want to do wireless programming. Series 2 modules do not allow for automatic IO Line Passing (this is required for toggling the reset pin when programming). Also make sure that you have a recent version of the firmware (10A5 or later). If you need to upgrade your firmware, use X-CTU (Windows only, unfortunately). If you confirmed these points, please follow the following steps.
!!!!Modifying the XBee-to-USB adaptor
If you are using a XBee Explorer USB (SparkFun Electronics) or XBee starter kit (Adafruit Industries), solder in a tiny jumper between the RTS pin and D3 as following picture:
!!!!Modifying the serial port settings (Windows only)
You have to make a slight change to the driver preferences. In the Device Manager, select the '''USB COM port'''. Then right click and select '''Properties'''. Click on the '''Port Settings''' tab, and click on '''Advanced...''', then make '''Set RTS On Close''' is selected and click '''OK''' to apply settings.
!!!!How to configure XBee modems
On Windows and Mac OS X, you can configure XBee modems with [[http://funnel.googlecode.com/files/XBeeConfigTool.zip | XBeeConfigTool]].
# Choose a proper serial port
# Choose a proper mode (Coordinator or End Devices)
# Choose a proper baud rate (57600bps)
# Set a proper PAN ID (e.g. 1234, should be same on both)
# Set a proper MY ID (e.g. 1, for end devices only)
# Press the Configure button to configure the XBee modem
!!!! Uploading sketches from an Arduino IDE to a FIO board
# Choose '''Tools/Board/Arduino Pro or Pro Mini (8MHz)'''
# Choose a proper serial port in '''Tools/Serial Port'''
# Write a sketch and press the Upload button
!!!Automatic (Software) Reset
Rather then requiring a physical press of the reset button before an upload, the Arduino Fio is designed in a way that allows it to be reset by software running on a connected computer. One of the pins on the six-pin header is connected to the reset line of the ATmega328P via a 100 nanofarad capacitor. This pin connects to one of the hardware flow control lines of the USB-to-serial convertor connected to the header: RTS when using an FTDI cable, DTR when using the Sparkfun breakout board. 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 the reset line can be well-coordinated with the start of the upload.
This setup has other implications. When the Fio 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 Pro. 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 dimensions of the Fio PCB are approximately 1.1" x 2.6".