Posted on 6 Comments

Basic Knowledge of Arduino Uno

What is Arduino Uno

Arduino Uno is a microcontroller board dependent on 8-piece ATmega328P microcontroller. Alongside ATmega328P, it comprises different parts, for example, gem oscillator, sequential correspondence, voltage controller, and so forth to help the microcontroller. Arduino Uno has 14 advanced information/yield pins (out of which 6 can be utilized as PWM yields), 6 simple info sticks, a USB association, A Power barrel jack, an ICSP header and a reset catch. The pin description of arduino uno and its Technical Specifications is as following table:

Pin CategoryPin NameDetails
PowerVin, 3.3V, 5V, GNDVin: Input voltage to Arduino when using an external power source.5V: Regulated power supply used to power microcontroller and other components on the board.3.3V: 3.3V supply generated by on-board voltage regulator. Maximum current draw is 50mA.GND: ground pins.
ResetResetResets the microcontroller.
Analog PinsA0 – A5Used to provide analog input in the range of 0-5V
Input/Output PinsDigital Pins 0 – 13Can be used as input or output pins.
Serial0(Rx), 1(Tx)Used to receive and transmit TTL serial data.
External Interrupts2, 3To trigger an interrupt.
PWM3, 5, 6, 9, 11Provides 8-bit PWM output.
SPI10 (SS), 11 (MOSI), 12 (MISO) and 13 (SCK)Used for SPI communication.
Inbuilt LED13To turn on the inbuilt LED.
TWIA4 (SDA), A5 (SCA)Used for TWI communication.
AREFAREFTo provide reference voltage for input voltage.
Technical Specifications
MicrocontrollerATmega328P – 8 bit AVR family microcontroller
Operating Voltage5V
Recommended Input Voltage7-12V
Input Voltage Limits6-20V
Analog Input Pins6 (A0 – A5)
Digital I/O Pins14 (Out of which 6 provide PWM output)
DC Current on I/O Pins40 mA
DC Current on 3.3V Pin50 mA
Flash Memory32 KB (0.5 KB is used for Bootloader)
SRAM2 KB
EEPROM1 KB
Frequency (Clock Speed)16 MHz

How to use Arduino Board

The 14 computerized input/yield pins can be utilized as information or yield sticks by utilizing pinMode(), digitalRead() and digitalWrite() works in arduino programming. Each stick work at 5V and can give or get a limit of 40mA current, and has an inside draw up resistor of 20-50 KOhms which are detached as a matter of course. Out of these 14 sticks, a few pins have explicit capacities as recorded beneath:

  • Serial Pins 0 (Rx) and 1 (Tx): Rx and Tx pins are used to receive and transmit TTL serial data. They are connected with the corresponding ATmega328P USB to TTL serial chip.
  • External Interrupt Pins 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.
  • PWM Pins 3, 5, 6, 9 and 11: These pins provide an 8-bit PWM output by using analogWrite() function.
  • SPI Pins 10 (SS), 11 (MOSI), 12 (MISO) and 13 (SCK): These pins are used for SPI communication.
  • In-built LED Pin 13: This pin is connected with an built-in LED, when pin 13 is HIGH – LED is on and when pin 13 is LOW, its off.

Alongside 14 Digital pins, there are 6 simple info sticks, every one of which give 10 bits of goals, for example 1024 unique qualities. They measure from 0 to 5 volts yet this point of confinement can be expanded by utilizing AREF stick with simple Reference() work.

  • Analog pin 4 (SDA) and pin 5 (SCA) also used for TWI communication using Wire library.

Arduino Uno has a couple of other pins as explained below:

  • AREF: Used to provide reference voltage for analog inputs with analogReference() function.
  • Reset Pin: Making this pin LOW, resets the microcontroller.

Arduino Uno Communication

Arduino can be utilized to speak with a PC, another Arduino board or different microcontrollers. The ATmega328P microcontroller gives UART TTL (5V) sequential correspondence which should be possible utilizing computerized stick 0 (Rx) and advanced stick 1 (Tx). An ATmega16U2 on the board channels this sequential correspondence over USB and shows up as a virtual com port to programming on the PC. The ATmega16U2 firmware utilizes the standard USB COM drivers, and no outside driver is required. Nonetheless, on Windows, an .inf document is required. The Arduino programming incorporates a sequential screen which enables basic literary information to be sent to and from the Arduino board. There are two RX and TX LEDs on the arduino board which will streak when information is being transmitted by means of the USB-to-sequential chip and USB association with the PC (not for sequential correspondence on pins 0 and 1). A SoftwareSerial library takes into account sequential correspondence on any of the Uno’s advanced pins. The ATmega328P additionally bolsters I2C (TWI) and SPI correspondence. The Arduino programming incorporates a Wire library to rearrange utilization of the I2C transport.

Arduino Uno to ATmega328 Pin Mapping

When ATmega328 chip is used in place of Arduino Uno, or vice versa, the image below shows the pin mapping between the two.

Arduino Uno to ATmega328 Pin Mapping
Arduino Uno to ATmega328 Pin Mapping

Software

Arduino IDE (Integrated Development Environment) is required to program the Arduino Uno board. Download it here.

Programming Arduino

Once arduino IDE is installed on the computer, connect the board with computer using USB cable. Now open the arduino IDE and choose the correct board by selecting Tools>Boards>Arduino/Genuino Uno, and choose the correct Port by selecting Tools>Port. Arduino Uno is programmed using Arduino programming language based on Wiring. To get it started with Arduino Uno board and blink the built-in LED, load the example code by selecting Files>Examples>Basics>Blink. Once the example code (also shown below) is loaded into your IDE, click on the ‘upload’ button given on the top bar. Once the upload is finished, you should see the Arduino’s built-in LED blinking.  Below is the example code for blinking:

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}

Applications of Arduino Uno

  • Prototyping of Electronics Products and Systems
  • Multiple DIY Projects.
  • Easy to use for beginner level DIYers and makers.
  • Projects requiring Multiple I/O interfaces and communications.

Arduino Uno 2D Model

Arduino Uno 2D Model
Arduino Uno 2D Model

Arduino Uno Datasheet

Arduino Uno Arduino Uno R3 Front Arduino Uno R3 Back Arduino Uno R2 Front Arduino Uno SMD Arduino Uno Front Arduino Uno Back Overview The Arduino Uno is a microcontroller board based on the ATmega328 (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 a AC-to-DC adapter or battery to get started. The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter. Revision 2 of the Uno board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU mode. Revision 3 of the board has the following new features:  1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible both with the board that use the AVR, which operate with 5V and with the Arduino Due that operate with 3.3V. The second one is a not connected pin, that is reserved for future purposes.  Stronger RESET circuit.  Atmega 16U2 replace the 8U2. “Uno” means one in Italian and is named to mark the upcoming release of Arduino 1.0. The Uno and version 1.0 will be the reference versions of Arduino, moving forward. The Uno is the latest in a series of USB Arduino boards, and the reference model for the Arduino platform; for a comparison with previous versions, see the index of Arduino boards. 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 EAGLE files: arduino-uno-Rev3-reference-design.zip (NOTE: works with Eagle 6.0 and newer) Schematic: arduino-uno-Rev3-schematic.pdf Note: The Arduino reference design can use an Atmega8, 168, or 328, Current models use an ATmega328, but an Atmega8 is shown in the schematic for reference. The pin configuration is identical on all three processors.

Power

The Arduino Uno 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 50 mA.  GND. Ground pins.

Memory

The ATmega328 has 32 KB (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 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 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. 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 ATmega328 ports. The mapping for the Atmega8, 168, and 328 is identical. Communication The Arduino Uno 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; see the documentation for details. For SPI communication, use the SPI library.

Programming

The Arduino Uno can be programmed with the Arduino software (download). Select “Arduino Uno from the Tools > Board menu (according to the microcontroller on your board). For details, see the reference and tutorials. The ATmega328 on the Arduino Uno 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. The ATmega16U2 (or 8U2 in the rev1 and rev2 boards) firmware source code is available . The ATmega16U2/8U2 is loaded with a DFU bootloader, which can be activated by:  On Rev1 boards: connecting the solder jumper on the back of the board (near the map of Italy) and then resetting the 8U2.  On Rev2 or later boards: there is a resistor that pulling the 8U2/16U2 HWB line to ground, making it easier to put into DFU mode. You can then use Atmel’s FLIP software (Windows) or the DFU programmer (Mac OS X and Linux) to load a new firmware. Or you can use the ISP header with an external programmer (overwriting the DFU bootloader). See this user-contributed tutorial for more information.

Automatic (Software) Reset

Rather than requiring a physical press of the reset button before an upload, the Arduino Uno 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 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 halfsecond 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 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; see this forum thread for details.

USB Overcurrent Protection

The Arduino Uno 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 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.

Advertisements

6 thoughts on “Basic Knowledge of Arduino Uno

  1. I have learn more from you article, and I cannot believe it’s free! I will follow you.

  2. Good post, keep up sir~

  3. I learned many knowledge about of arduino uno, it’s very very clear than I see the book by myself!

    Thanks blogger.

    1. Thanks! Cheers!

  4. Basic Knowledge of Arduino Uno is a good page! I believe there will have many students and engineers follow the 3celectrons here.

    1. Thank you for your admire! Cheers!

Leave a Reply

Your email address will not be published.