Why is the digital pin 13 a special pin?

The pullup resistors provide enough current to dimly light an LED connected to a pin that has been configured as an input. NOTE: Digital pin 13 is harder to use as a digital input than the other digital pins because it has an LED and resistor attached to it that’s soldered to the board on most boards.

What does pin 13 do in Arduino?

Pins 0-13 of the Arduino Uno serve as digital input/output pins. Pin 13 of the Arduino Uno is connected to the built-in LED. In the Arduino Uno – pins 3,5,6,9,10,11 have PWM capability.

What is pin 13 LED Arduino?

The LED on pin 13 is used by the optiboot loader (the one used on UNO): at Arduino boot time (the LED blinks a few times) when uploading a sketch to Arduino.

How are pins defined in Arduino Uno?

Arduino Uno (R3)

1. SS: Pin number 10 is used as a Slave Select.
2. MOSI: Pin number 11 is used as a Master Out Slave In.
3. MISO: Pin number 12 is used as a Master In Slave Out.
4. SCK: Pin number 13 is used as a Serial Clock.

How do I know if my Arduino pin is high?

The digitalRead() function is used to read the logic state at a pin. It is capable to tell wether the voltage at this pin is high (~ 5V) or low (~ 0V) or, in other words, if the pin is at logic state 1 or 0 (or HIGH/LOW). Notice that the digitalRead() function does not effectively measures the voltage at the pin.

What is the function of digitalWrite?

The digitalWrite() function is used to write a HIGH or a LOW value to a digital pin. If the pin has been configured as an OUTPUT with pinMode(), its voltage will be set to the corresponding value: 5V (or 3.3V on 3.3V boards) for HIGH, 0V (ground) for LOW.

How many arguments does the analogWrite () function have?

analogWrite() takes two or three arguments: pin : the number of the pin whose value you wish to set. value : the duty cycle: between 0 (always off) and 255 (always on).

What does pinMode 13 Input_pullup for?

This example demonstrates the use of INPUT_PULLUP with pinMode(). It monitors the state of a switch by establishing serial communication between your Arduino and your computer over USB. Additionally, when the input is HIGH, the onboard LED attached to pin 13 will turn on; when LOW, the LED will turn off.

How many pins Arduino has?

Microcontrollers

How do I know if my PIN is high or low?

The pin states can be checked by switching to the digital input mode programmatically. The input is “LOW” at 0V or “HIGH” at 5V. The program reads “0” as LOW and “1” as HIGH.