Note: This page refers to a product that is retired. Check out the Arduino UNO WiFi Rev2
The Arduino UNO WiFi is the same as a Arduino UNO Rev3 but with an integrated Wi-Fi module! The board is based on the ATmega328P with an ESP8266 Wi-Fi Module integrated (datasheet). 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 WiFi is support for OTA (over-the-air) programming, either for transfer of Arduino sketches or Wi-Fi firmware.
The Arduino UNO WiFi 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:
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).
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:
The Arduino UNO WiFi 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 WiFi 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 WiFi 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 WiFi 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 WiFi is the Ciao Library and using, for example, the REST connector.
On the Arduino UNO WiFi is pre-uploaded the RestServer sketch that allows you to command immediately your board via browser:
Connect to the Arduino UNO WiFi 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:
The Arduino UNO WiFi can be programmed as a classic Arduino UNO with the Arduino software (download). Select "Arduino UNO WiFi from the Tools > Board menu (according to the microcontroller on your board.
The new features of the Arduino UNO WiFi 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 WiFi 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.
Rather than requiring a physical press of the reset button before an upload, the Arduino UNO WiFi 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 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 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 "RESET-EN". You may also be able to disable the auto-reset by connecting a 110 ohm resistor from 5V to the reset line.
The Arduino UNO WiFi 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.
The maximum length and width of the UNO WiFi 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.
Digital I/O Pins | 20 |
PWM Output | 6 |
Power Consumption | 93 mA |
PCB Size | 53 x 68.5 mm |
Weight | 0.025 Kg |
Product Code | A000133 |
Microcontroller | ATmega328 |
Architecture | Atmel AVR 8-bit |
Operating Voltage | 5 V |
Flash memory | 32 KB |
SRAM | 2 KB |
Clock Speed | 16 MHz |
Analog I/O Pins | 6 |
EEPROM | 1 KB |
DC Current per I/O Pins | 40 mA |
Processor | ESP8266 |
Architecture | Tensilica Xtensa LX106 |
Operating Voltage | 3.3 V |
Flash Memory | 4 MB |
RAM | 8 MB instruction, 12 MB data |
Clock Speed | 80 MHz |
WiFi | 802.11 b/g/n 2.4 GHz |
Wake up time | < 2 ms |
This tutorial will guide you in the process of updating the firmware of your Arduino UNO WiFi board.
Connect the board at the USB port of your computer ready with Arduino Software (IDE) 1.8.0 or later.
To simplify the process, we have prepared a tool - UNO WiFi FirmwareUpdater - available in Arduino IDE 1.8.0 or later.
Follow these steps to enable this tools into Arduino software:
Now:
1/\*ESP Recovery sketch\*/ 2#include <Wire.h> 3#include <UnoWiFiDevEd.h> 4 5#define BAUD 9600 6WifiData ESPSerial; 7 8void setup() 9{ 10Serial.begin(BAUD); 11pinMode(13, OUTPUT); 12digitalWrite(13, LOW); 13 14ESPSerial.begin(BAUD); 15} 16 17void loop() 18{ 19while (Serial.available()) { 20char inChar = (char)Serial.read(); 21ESPSerial.write(inChar); 22} 23 24while (ESPSerial.available()) { 25char inChar = (char)ESPSerial.read(); 26Serial.write(inChar); 27} 28 29}
Warning: The process could last several minutes.