FUNCTIONS

Question 1

pinMode(pin, mode)

Answer 1

Purpose: Sets the mode of a specified pin (INPUT, OUTPUT).
Example:
pinMode(13, OUTPUT);

Question 2

digitalWrite(pin, value)

Answer 2

Purpose: Write a HIGH or LOW value to a pin.
Example:
digitalWrite(13, HIGH);

Question 3

digitalRead(pin)

Answer 3

Purpose: Reads the value from a specified digital pin.
Example:
int buttonState = digitalRead(7);

Question 4

analogWrite(pin, value)

Answer 4

Purpose: Write an analog value (PWM wave) to a pin.
Example:
analogWrite(9, 128);

Question 5

analogRead(pin)

Answer 5

Purpose: Reads the analog value from a pin.
Example:
int sensorValue = analogRead(A0);

Question 6

delay(ms)

Answer 6

Purpose: Pauses the program for a specified time.
Example:
delay(1000);

Question 7

millis()

Answer 7

Purpose: Returns the number of milliseconds since the board started.
Example:
unsigned long time = millis();

Question 8

Serial.begin(baudrate)

Answer 8

Purpose: Initializes serial communication at a certain baud rate.
Example:
Serial.begin(9600);

Question 9

Serial.print(data)

Answer 9

Purpose: Prints data to the serial monitor.
Example:
Serial.print(“Hello, world!”);

Question 10

Serial.println(data)

Answer 10

Purpose: Prints data followed by a new line.
Example:
Serial.println(“Line 1”);

Question 11

attachInterrupt(digitalPinToInterrupt(pin), ISR, mode)

Answer 11

Purpose: Attaches an interrupt to a pin.
Example:
attachInterrupt(digitalPinToInterrupt(2), blink, RISING);

Question 12

detachInterrupt(pin)

Answer 12

Purpose: Disables an interrupt attached to a pin.
Example:
detachInterrupt(digitalPinToInterrupt(2));

Question 13

map(value, fromLow, fromHigh, toLow, toHigh)

Answer 13

Purpose: Re-maps a number from one range to another.
Example:
int output = map(analogRead(A0), 0, 1023, 0, 255);

Question 14

constrain(value, min, max)

Answer 14

Purpose: Constrains a number to be within a range.
Example:
int val = constrain(analogRead(A0), 100, 900);

Question 15

randomSeed(seed)

Answer 15

Purpose: Initializes the pseudo-random number generator.
Example:
randomSeed(analogRead(0));

Question 16

random(min, max)

Answer 16

Purpose: Generates a random number between a given range.
Example:
int randNum = random(1, 10);

Question 17

noTone(pin)

Answer 17

Purpose: Stops the tone on a pin.
Example:
noTone(8);

Question 18

tone(pin, frequency)

Answer 18

Purpose: Generates a square wave of a certain frequency on a pin.
Example:
tone(8, 1000);

Question 19

shiftOut(dataPin, clockPin, bitOrder, value)

Answer 19

Purpose: Shifts out a byte of data one bit at a time.
Example:
shiftOut(11, 12, MSBFIRST, 0xFF);

Question 20

shiftIn(dataPin, clockPin, bitOrder)

Answer 20

Purpose: Shifts in a byte of data one bit at a time.
Example:
byte myData = shiftIn(11, 12, MSBFIRST);

Question 21

pulseIn(pin, value)

Answer 21

Purpose: Reads a pulse (HIGH or LOW) on a pin.
Example:
unsigned long duration = pulseIn(7, HIGH);

Question 22

min(x, y)

Answer 22

Purpose: Returns the smaller of two numbers.
Example:
int smaller = min(10, 20);

Question 23

max(x, y)

Answer 23

Purpose: Returns the larger of two numbers.
Example:
int larger = max(10, 20);

Question 24

abs(x)

Answer 24

Purpose: Returns the absolute value of a number.
Example:
int absolute = abs(-5);

Question 25

sqrt(x)

Answer 25

Purpose: Calculates the square root of a number.
Example:
float root = sqrt(16);

Question 26

pow(base, exponent)

Answer 26

Purpose: Raises a number to a given power.
Example:
float result = pow(2, 3); // 2 raised to the power of 3

Question 27

sin(angle)

Answer 27

Purpose: Calculates the sine of an angle (in radians).
Example:
float sineValue = sin(PI / 2);

Question 28

cos(angle)

Answer 28

Purpose: Calculates the cosine of an angle (in radians).
Example:
float cosineValue = cos(PI);

Question 29

tan(angle)

Answer 29

Purpose: Calculates the tangent of an angle (in radians).
Example:
float tanValue = tan(PI / 4);

Question 30

lowByte(x)

Answer 30

Purpose: Extracts the low byte of a two-byte number.
Example:
byte lower = lowByte(0xABCD);

Question 31

highByte(x)

Answer 31

Purpose: Extracts the high byte of a two-byte number.
Example:
byte higher = highByte(0xABCD);

Question 32

bitRead(value, bit)

Answer 32

Purpose: Reads a specific bit of a number.
Example:
int bitValue = bitRead(0b1010, 2); // Read bit 2

Question 33

bitWrite(value, bit, bitValue)

Answer 33

Purpose: Writes a specific bit of a number.
Example:
bitWrite(x, 1, 1); // Set bit 1 of x to 1

Question 34

bitSet(value, bit)

Answer 34

Purpose: Sets a specific bit of a number to 1.
Example:
bitSet(x, 1); // Set bit 1 to 1

Question 35

bitClear(value, bit)

Answer 35

Purpose: Clears a specific bit of a number (sets it to 0).
Example:
bitClear(x, 1); // Clear bit 1

Question 36

bit(bit)

Answer 36

Purpose: Returns the value of a specific bit.
Example:
byte myBit = bit(3); // Returns 0b1000