Arduino uno operation system

The Arduino Uno R3 is a microcontroller board in view of the ATmega328 (datasheet). It has 14 advanced info/yield pins (of which 6 can be utilized as PWM yields), 6 simple sources of info, a 16 MHz precious stone oscillator, a USB association, a power jack, an ICSP header, and a reset catch. It contains everything expected to help the microcontroller; essentially associate it to a PC with a USB link or power it with an AC-to-DC connector or battery to begin.

The Uno varies from every previous board in that it doesn't utilize the FTDI USB-to-serial driver chip. Rather, it includes the Atmega16U2 (Atmega8U2 up to variant R2) customized as a USB-to-serial converter.

Modification 2 of the Uno board has a resistor pulling the 8U2 HWB line to ground, making it less demanding to put into DFU mode.

Amendment 3 of the board has the accompanying new highlights:

·         1.0 pinout: included SDA and SCL pins that are close to the AREF stick and two other new sticks put close to the RESET stick, the IOREF that enable the shields to adjust to the voltage gave from the board. In future, shields will be good both with the board that utilization the AVR, which work with 5V and with the Arduino Due that work with 3.3V. The second one is a not associated stick, that is saved for future purposes.

·         Stronger RESET circuit.

·         Atmega 16U2 supplant the 8U2.

"Uno" implies one in Italian and is named to stamp the up and coming arrival of Arduino 1.0. The Uno and form 1.0 will be the reference renditions of Arduino, advancing. The Uno is the most recent in a progression of USB Arduino sheets, and the reference show for the Arduino stage; for an examination with past renditions, see the list of Arduino sheets.

Summary

Microcontroller	ATmega328
Operating Voltage	5V
Input Voltage (recommended)	7-12V
Input Voltage (limits)	6-20V
Digital I/O Pins	14 (of which 6 provide PWM output)
Analog Input Pins	6
DC Current per I/O Pin	40 mA
DC Current for 3.3V Pin	50 mA
Flash Memory	32 KB (ATmega328) of which 0.5 KB used by bootloader
SRAM	2 KB (ATmega328)
EEPROM	1 KB (ATmega328)
Clock Speed	16 MHz

Schematic & Reference Design

Note: The Arduino reference configuration can utilize an Atmega8, 168, or 328, Current models utilize an ATmega328, however an Atmega8 is appeared in the schematic for reference. The stick arrangement is indistinguishable on every one of the three processors.

Power

The Arduino Uno can be fueled by means of the USB association or with an outer power supply. The power source is chosen naturally.

Outside (non-USB) power can come either from an AC-to-DC connector (divider wart) or battery. The connector can be associated by stopping a 2.1mm focus positive connect to the board's energy jack. Leads from a battery can be embedded in the Gnd and Vin stick headers of the POWER connector.

The board can work on an outside supply of 6 to 20 volts. On the off chance that provided with under 7V, notwithstanding, the 5V stick may supply under five volts and the board might be shaky. In the event that utilizing more than 12V, the voltage controller may overheat and harm the board. The prescribed range is 7 to 12 volts.

The power pins are as per the following:

·         VIN. The info voltage to the Arduino board when it's utilizing an outside power source (rather than 5 volts from the USB association or other managed control source). You can supply voltage through this stick, or, if providing voltage by means of the power jack, get to it through this stick.

·         5V. The managed control supply used to control the microcontroller and different segments on the board. This can come either from VIN by means of an on-board controller, or be provided by USB or another directed 5V supply.

·         3V3. A 3.3 volt supply produced by the on-board controller. Most extreme current draw is 50 mA.

·         GND. Ground pins.

Memory

The ATmega328 has 32 KB (with 0.5 KB utilized for the bootloader). It likewise has 2 KB of SRAM and 1 KB of EEPROM (which can be perused and composed with the EEPROM library).

Input and Output

Each of the 14 advanced sticks on the Uno can be utilized as an info or yield, utilizing pinMode(), digitalWrite(), and digitalRead()functions. They work at 5 volts. Each stick can give or get a greatest of 40 mA and has an interior draw up resistor (separated as a matter of course) of 20-50 kOhms. What's more, a few pins have specific capacities:

·         Serial: 0 (RX) and 1 (TX). Used to get (RX) and transmit (TX) TTL serial information. These pins are associated with the relating pins of the ATmega8U2 USB-to-TTL Serial chip.

·         Outside Interrupts: 2 and 3. These pins can be designed to trigger a hinder on a low esteem, a rising or falling edge, or an adjustment in esteem. See the attachInterrupt() work for points of interest.

·         PWM: 3, 5, 6, 9, 10, and 11. Give 8-bit PWM yield with the analogWrite() work.

·         SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins bolster SPI correspondence utilizing the SPI library.

·         Driven: 13. There is a worked in LED associated with advanced stick 13. At the point when the stick is HIGH esteem, the LED is on, when the stick is LOW, it's off.

The Uno has 6 simple information sources, marked A0 through A5, each of which give 10 bits of determination (i.e. 1024 unique esteems). Of course they measure from ground to 5 volts, however is it conceivable to change the upper end of their range utilizing the AREF stick and the analogReference() work. Moreover, a few pins have particular usefulness:

·         TWI: A4 or SDA stick and A5 or SCL stick. Bolster TWI correspondence utilizing the Wire library.

·         There are two or three different sticks on the board:

·         AREF. Reference voltage for the simple sources of info. Utilized with analogReference().

·         Reset. Convey this line LOW to reset the microcontroller. Ordinarily used to add a reset catch to shields which obstruct the one on the boar

See likewise the mapping between Arduino pins and ATmega328 ports. The mapping for the Atmega8, 168, and 328 is indistinguishable.

Communication

The Arduino Uno has various offices for speaking with a PC, another Arduino, or different microcontrollers. The ATmega328 gives UART TTL (5V) serial correspondence, which is accessible on computerized pins 0 (RX) and 1 (TX). An ATmega16U2 on the board channels this serial correspondence over USB and shows up as a virtual com port to programming on the PC. The '16U2 firmware utilizes the standard USB COM drivers, and no outside driver is required. Be that as it may, on Windows, an .inf record is required. The Arduino programming incorporates a serial screen which enables basic printed information to be sent to and from the Arduino board. The RX and TX LEDs on the board will streak when information is being transmitted by means of the USB-to-serial chip and USB association with the PC (however not for serial correspondence on pins 0 and 1).

A SoftwareSerial library takes into consideration serial correspondence on any of the Uno's advanced pins.

The ATmega328 additionally bolsters I2C (TWI) and SPI correspondence. The Arduino programming incorporates a Wire library to improve utilization of the I2C transport; see the documentation for subtle elements. For SPI correspondence, utilize the SPI library.

Programming

The Arduino Uno can be modified with the Arduino programming (download). Select "Arduino Uno from the Tools > Board menu (as per the microcontroller on your board). For points of interest, see the reference and instructional exercises.

The ATmega328 on the Arduino Uno comes preburned with a bootloader that enables you to transfer new code to it without the utilization of an outside equipment software engineer. It conveys utilizing the first STK500 convention (reference, C header records).

You can likewise sidestep the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header; see these directions for subtle elements.

The ATmega16U2 (or 8U2 in the rev1 and rev2 sheets) firmware source code is accessible . The ATmega16U2/8U2 is stacked with a DFU bootloader, which can be enacted by:

·         On Rev1 sheets: associating the bind jumper on the back of the board (close to the guide of Italy) and after that resetting the 8U2.

·         On Rev2 or later sheets: there is a resistor that pulling the 8U2/16U2 HWB line to ground, making it less demanding to put into DFU mode.

You would then be able to utilize Atmel's FLIP programming (Windows) or the DFU software engineer (Mac OS X and Linux) to stack another firmware. Or, on the other hand you can utilize the ISP header with an outside software engineer (overwriting the DFU bootloader). See this client contributed instructional exercise for more data.

Automatic (Software) Reset

As opposed to requiring a physical press of the reset catch before a transfer, the Arduino Uno is planned in a way that enables it to be reset by programming running on an associated PC. One of the equipment stream control lines (DTR) of theATmega8U2/16U2 is associated with the reset line of the ATmega328 by means of a 100 nanofarad capacitor. At the point when this line is declared (taken low), the reset line drops sufficiently long to reset the chip. The Arduino programming utilizes this capacity to enable you to transfer code by basically squeezing the transfer catch in the Arduino condition. This implies the bootloader can have a shorter timeout, as the bringing down of DTR can be all around composed with the begin of the transfer.

This setup has different ramifications. At the point when the Uno is associated with either a PC running Mac OS X or Linux, it resets each time an association is made to it from programming (by means of USB). For the accompanying half-second or something like that, the bootloader is running on the Uno. While it is customized to overlook distorted information (i.e. anything other than a transfer of new code), it will block the initial couple of bytes of information sent to the board after an association is opened. On the off chance that an outline running on the load up gets one-time design or other information when it initially begins, ensure that the product with which it imparts holds up a moment in the wake of opening the association and before sending this information.

The Uno contains a follow that can be sliced to impair the auto-reset. The cushions on either side of the follow can be bound together to re-empower it. It's marked "RESET-EN". You may likewise have the capacity to impair the auto-reset by associating a 110 ohm resistor from 5V to the reset line; see this discussion string for subtle elements.

USB Overcurrent Protection

The Arduino Uno has a resettable polyfuse that shields your PC's USB ports from shorts and overcurrent. Albeit most PCs give their own inside insurance, the breaker gives an additional layer of security. On the off chance that more than 500 mA is connected to the USB port, the circuit will naturally break the association until the point that the short or over-burden is expelled.

Physical Characteristics

The most extreme length and width of the Uno PCB are 2.7 and 2.1 inches separately, with the USB connector and power jack reaching out past the previous measurement. Four screw openings enable the board to be connected to a surface or case. Note that the separation between advanced pins 7 and 8 is 160 mil (0.16"), not an even numerous of the 100 mil dividing of alternate pins.