Arduino UNO is a microcontroller board based on the ATmega328P microcontroller. It is one of the most popular boards in the Arduino family, known for its simplicity and versatility, and is widely used by makers, hobbyists, and professionals for a wide range of projects.
The Arduino UNO board has a range of features that make it ideal for prototyping and experimentation. It has 14 digital input/output pins, 6 analog input pins, a 16 MHz quartz crystal, a USB connection for programming and power, and a power jack. It also has a reset button, a power LED, and a built-in LED that can be used for testing and debugging.
The board can be programmed using the Arduino IDE, a software development environment that makes it easy to write and upload code to the board. The Arduino IDE is based on the C++ programming language and has a library of pre-written code, known as "sketches," that can be easily modified and adapted for different projects.
Arduino might be considered as the child of traditional desktop and laptop computers. At its roots, the Arduino is essentially a small portable computer. It is capable of taking inputs (such as the push of a button or a reading from a light sensor) and interpreting that information to control various outputs (like a blinking LED light or an electric motor).
ARDUINO PINS EXPLAINED IN DETAIL
Digital I/O ports are used to connect to other components or modules, to receive an input signal, or to send a control signal.
Usually, we name it by adding a "D" in front of the number, such as D13.
The USB interface is used to provide power, upload code or communicate with PCs.
LED L is connected to digital I/O port 13 (D13).
LED TX, RX is used to indicate the state of the serial communication.
The DC interface is connected to DC power to provide power for the board.
Power ports can provide power for electronic components and modules.
Analog I/O ports can be used to measure analog signals.
LED ON is used to indicate the power state.
Power (USB / Barrel Jack)(1) and (2):
Every Arduino board needs a way to be connected to a power source. The Arduino UNO can be powered from a USB cable coming from your computer or a wall power supply that is terminated in a barrel jack.
NOTE: Do not use a power supply greater than 20 Volts as you will overpower (and thereby destroy) your Arduino. The recommended voltage for most Arduino models is between 6 and 12 Volts.
GND (3):
There are several GND pins on the Arduino, any of which can be used to ground your circuit.
5V (4)& 3.3V (5):
The 5V pin supplies 5 volts of power, and the 3.3V pin supplies 3.3 volts of power. Most of the simple components used with the Arduino run happily off of 5 or 3.3 volts.
Analog (6):
The area of pins under the ‘Analog In’ label (A0 through A5 on the UNO) are Analog In pins. These pins can read the signal from an analog sensor (like a temperature sensor) and convert it into a digital value that we can read.
Digital (7):
Across from the analog pins are the digital pins (0 through 13 on the UNO). These pins can be used for both digital input (like telling if a button is pushed) and digital output (like powering an LED).
PWM (8):
We may have noticed the tilde (~) next to some of the digital pins (3, 5, 6, 9, 10, and 11 on the UNO). These pins act as normal digital pins, but can also be used for something called Pulse-Width Modulation (PWM). We have a tutorial on PWM, but for now, think of these pins as being able to simulate analog output (like fading an LED in and out).
AREF (9):
It stands for Analog Reference. Most of the time you can leave this pin alone. It is sometimes used to set an external reference voltage (between 0 and 5 Volts) as the upper limit for the analog input pins
Reset Button:
Just like the original Nintendo, the Arduino has a reset button (10). Pushing it will temporarily connect the reset pin to ground and restart any code that is loaded on the Arduino. This can be very useful if your code doesn’t repeat, but you want to test it multiple times. Unlike the original Nintendo however, blowing on the Arduino doesn’t usually fix any problems.
Power LED Indicator:
Just beneath and to the right of the word “UNO” on your circuit board, there’s a tiny LED next to the word ‘ON’ (11). This LED should light up whenever you plug your Arduino into a power source. If this light doesn’t turn on, there’s a good chance something is wrong.
TXT RX LEDs are short for transmit, RX is short for receive. These markings appear quite a bit in electronics to indicate the pins responsible for serial communication. In our case, there are two places on the Arduino UNO where TX and RX appear once by digital pins 0 and 1, and a second time next to the TX and RX indicator LEDs (12). These LEDs will give us some nice visual indications whenever our Arduino is receiving or transmitting data (like when we’re loading a new program onto the board).
Main IC:
The black thing with all the metal legs is an IC, or Integrated Circuit (13). Think of it as the brains of our Arduino. The main IC on the Arduino is slightly different from board type to board type, but is usually from the ATmega line of IC’s from the ATMEL company.
This can be important, as you may need to know the IC type (along with your board type) before loading up a new program from the Arduino software. This information can usually be found in writing on the top side of the IC. If you want to know more about the difference between various IC’s, reading the datasheets is often a good idea.
Voltage Regulator:
It is potentially useful to know that it is there and what it’s for. The voltage regulator does exactly what it says – it controls the amount of voltage that is let into the Arduino board. Think of it as a kind of gatekeeper; it will turn away an extra voltage that might harm the circuit. Of course, it has its limits, so don’t hook up your Arduino to anything greater than 20 volts.