Arduino UNO WiFi
The UNO WiFi board is the Arduino UNO with
integrated WiFi. For beginner and advanced users
alike.
The Arduino UNO WiFi board is based on the ATmega328 and it has an integrated
ESP8266 WiFi Module. If you are starting out with Arduino, or starting with IoT, this is
the board to get.
Power
The Arduino Uno Wi-Fi can be powered via the USB connection or with an external
power supply. The power source is selected automatically.External (non-USB) power
can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be
connected by plugging a 2.1mm center-positive plug into the board's power jack.
Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER
connector.
The board can operate on an external supply of 6 to 20 volts. If supplied with less
than 7V, however, the 5V pin may supply less than five volts and the board may be
unstable. If using more than 12V, the voltage regulator may overheat and damage
the board. The recommended range is 7 to 12 volts.
The power pins are as follows:
VIN. The input voltage to the Arduino board when it's using an external power source
(as opposed to 5 volts from the USB connection or other regulated power source).
You can supply voltage through this pin, or, if supplying voltage via the power jack,
access it through this pin.
5V. This pin outputs a regulated 5V from the regulator on the board. The board can
be supplied with power either from the DC power jack (7 - 12V), the USB connector
(5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins
bypasses the regulator, and can damage your board. We don't advise it.
3V3. A 3.3 volt supply generated by the on-board regulator. Maximum current draw is
1 A (according to the power input source).
GND. Ground pins.
IOREF. This pin on the Arduino board provides the voltage reference with which the
microcontroller operates. A properly configured shield can read the IOREF pin
voltage and select the appropriate power source or enable voltage translators on the
outputs for working with the 5V or 3.3V supplies.
Memory
The ATmega328 has 32 KB Flash (with 0.5 KB used for the bootloader). It also has 2
KB of SRAM and 1 KB of EEPROM (which can be read and written with the
EEPROM library).
Input and Output
Each of the 14 digital pins on the Uno 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 specialised 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 ATmega8U2 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 using the SPI library.
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 Uno has 6 analog inputs,
labeled A0 through A5, 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 the analogReference()
function. Additionally, some pins have specialized functionality:
TWI: A4 or SDA pin and A5 or SCL pin. Support TWI communication using the Wire
library. NOTE: the A4 or SDA pin and A5 or SCL pin are in use by the IO Expander
SC16IS750IBS. 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.
Communication
The Arduino Uno Wi-Fi has a number of facilities for communicating with a computer,
another Arduino, or other microcontrollers. The ATmega328 provides UART TTL (5V)
serial communication, which is available on digital pins 0 (RX) and 1 (TX). An
ATmega16U2 on the board channels this serial communication over USB and
appears as a virtual com port to software on the computer. The 16U2 firmware uses
the standard USB COM drivers, and no external driver is needed. However, on
Windows, a .inf file is required. 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 USB-to-serial 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 Uno's digital
pins.
The ATmega328 also supports I2C (TWI) and SPI communication. The Arduino
software includes a Wire library to simplify use of the I2C bus; For SPI
communication, use the SPI library.
On the Arduino Uno Wi-Fi there’s a SC16IS750IBS IO Expander Single UART with
I2C-bus/SPI interface that allows the communication between AtMega 16u2, AtMega
328p and the ESP8266EX.
The Arduino Uno Wi-Fi allow you to communicate via Wi-Fi with your sensors or
actuators mounted on your board to create easily and quickly your IoT System. You
can use your Arduino Uno Wi-Fi as a client of your Wi-Fi network, as a server to
connect other client devices or you can create an ad’hoc Wi-Fi connection.
The perfect way to communicate to internet via your Arduino Uno Wi-Fi is the Ciao
Library and using, for example, the REST connector.
On the Arduino Uno Wi-Fi is pre-uploaded the RestServer sketch that allows you to
command immediately your board via browser:
Connect to the Arduino Uno Wi-Fi SSID and go to the link http://192.168.240.1/arduino/digital/13/1
to turn ON the LED L
Here other possible commands:
* "/arduino/digital/13" -> digitalRead(13)
* "/arduino/digital/13/1" -> digitalWrite(13, HIGH)
* "/arduino/analog/2/123" -> analogWrite(2, 123)
* "/arduino/analog/2" -> analogRead(2)
* "/arduino/mode/13/input" -> pinMode(13, INPUT)
* "/arduino/mode/13/output" -> pinMode(13, OUTPUT)
Programming
The Arduino Uno Wi-Fi can be programmed as a classic Arduino Uno with the Arduino software
(download). Select "Arduino Uno Wi-Fi from the Tools > Board menu (according to the
microcontroller on your board.
The new features of the Arduino Uno Wi-Fi allow you to upload your sketch via Wi-Fi
(in the same way of Arduino Yun), without any wired connection to your PC and your
board.
The ATmega328 on the Arduino Uno Wi-Fi comes pre-burned 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.
You can also bypass the bootloader and program the microcontroller through the
ICSP (In-Circuit Serial Programming) header using Arduino ISP or similar.
Automatic (Software) Reset
Rather than requiring a physical press of the reset button before an upload, the
Arduino Uno Wi-Fi 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
ATmega8U2/16U2 is connected to the reset line of the 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.
This setup has other implications. When the Uno WiFi 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 Uno. 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 onetime 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 Uno WiFi contains a trace that can be cut to disable the auto-reset. The pads on
either side of the trace can be soldered together to re-enable it. It's labeled "RESETEN". You may also be able to disable the auto-reset by connecting a 110 ohm
resistor from 5V to the reset line.
USB Overcurrent Protection
The Arduino Uno Wi-Fi has a resettable polyfuse that protects your computer's USB
ports from shorts and overcurrent. Although most computers provide their own
internal protection, the fuse provides an extra layer of protection. If more than 500
mA is applied to the USB port, the fuse will automatically break the connection until
the short or overload is removed.
Physical Characteristics
The maximum length and width of the Uno Wi-Fi PCB are 2.7 and 2.1 inches
respectively, with the USB connector and power jack extending beyond the former
dimension. Four screw holes allow the board to be attached to a surface or case.
Note that the distance between digital pins 7 and 8 is 160 mil (0.16"), not an even
multiple of the 100 mil spacing of the other pins.
Overview
The Arduino Uno Wi-Fi is the new Arduino Uno with an integrated Wi-Fi module! The board
is based on the ATmega328P (datasheet (http://www.atmel.com/images/Atmel-8271-8bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328328P_datasheet_Complete.pdf)) with an ESP8266 Wi-Fi Module integrated (datasheet
(http://download.arduino.org/products/UNOWIFI/0A-ESP8266-Datasheet-EN-v4.3.pdf)). It
has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a
16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset
button. It contains everything needed to support the microcontroller; simply connect it to a
computer with a USB cable or power it with an AC-to-DC adapter or battery to get started.
The ESP8266 Wi-Fi Module is a self contained SoC with integrated TCP/IP protocol stack
that can give access to your Wi-Fi network. (Or the device can act as an access point.) One
useful feature of Uno Wi-Fi is support for OTA (over-the-air) programming, either for
transfer of Arduino sketches or Wi-Fi firmware.
ARDUINO MICROPROCESSOR
Processor
Architecture
ARDUINO
MICROCONTROLLER
ESP8266
Tensilica Xtensa
LX106
GENERAL
Digital I/O Pins
20
PWM Output
6
Power Consumption
93 mA
5V
PCB Size
53 x 68.5 mm
Microcontroller
ATmega328
Architecture
Atmel AVR
8-bit
Operating Voltage
Operating
Voltage
3.3 V
Flash Memory
4 MB
Flash memory
32 KB
Weight
0.025 Kg
RAM
8 MB instruction, 12
MB data
SRAM
2 KB
Product Code
A000133
Clock Speed
16 MHz
Clock Speed
80 MHz
Analog I/O Pins
6
WiFi
802.11 b/g/n 2.4
GHz
EEPROM
1 KB
DC Current per I/O
Pins
40 mA
Wake up time
< 2 ms
http://www.arduino.org/products/boards/arduino-uno-wifi
9/28/2016