FUNCTIONS Flashcards
pinMode(pin, mode)
Purpose: Sets the mode of a specified pin (INPUT, OUTPUT).
Example:
pinMode(13, OUTPUT);
digitalWrite(pin, value)
Purpose: Write a HIGH or LOW value to a pin.
Example:
digitalWrite(13, HIGH);
digitalRead(pin)
Purpose: Reads the value from a specified digital pin.
Example:
int buttonState = digitalRead(7);
analogWrite(pin, value)
Purpose: Write an analog value (PWM wave) to a pin.
Example:
analogWrite(9, 128);
analogRead(pin)
Purpose: Reads the analog value from a pin.
Example:
int sensorValue = analogRead(A0);
delay(ms)
Purpose: Pauses the program for a specified time.
Example:
delay(1000);
millis()
Purpose: Returns the number of milliseconds since the board started.
Example:
unsigned long time = millis();
Serial.begin(baudrate)
Purpose: Initializes serial communication at a certain baud rate.
Example:
Serial.begin(9600);
Serial.print(data)
Purpose: Prints data to the serial monitor.
Example:
Serial.print(“Hello, world!”);
Serial.println(data)
Purpose: Prints data followed by a new line.
Example:
Serial.println(“Line 1”);
attachInterrupt(digitalPinToInterrupt(pin), ISR, mode)
Purpose: Attaches an interrupt to a pin.
Example:
attachInterrupt(digitalPinToInterrupt(2), blink, RISING);
detachInterrupt(pin)
Purpose: Disables an interrupt attached to a pin.
Example:
detachInterrupt(digitalPinToInterrupt(2));
map(value, fromLow, fromHigh, toLow, toHigh)
Purpose: Re-maps a number from one range to another.
Example:
int output = map(analogRead(A0), 0, 1023, 0, 255);
constrain(value, min, max)
Purpose: Constrains a number to be within a range.
Example:
int val = constrain(analogRead(A0), 100, 900);
randomSeed(seed)
Purpose: Initializes the pseudo-random number generator.
Example:
randomSeed(analogRead(0));
random(min, max)
Purpose: Generates a random number between a given range.
Example:
int randNum = random(1, 10);
noTone(pin)
Purpose: Stops the tone on a pin.
Example:
noTone(8);
tone(pin, frequency)
Purpose: Generates a square wave of a certain frequency on a pin.
Example:
tone(8, 1000);
shiftOut(dataPin, clockPin, bitOrder, value)
Purpose: Shifts out a byte of data one bit at a time.
Example:
shiftOut(11, 12, MSBFIRST, 0xFF);
shiftIn(dataPin, clockPin, bitOrder)
Purpose: Shifts in a byte of data one bit at a time.
Example:
byte myData = shiftIn(11, 12, MSBFIRST);
pulseIn(pin, value)
Purpose: Reads a pulse (HIGH or LOW) on a pin.
Example:
unsigned long duration = pulseIn(7, HIGH);
min(x, y)
Purpose: Returns the smaller of two numbers.
Example:
int smaller = min(10, 20);
max(x, y)
Purpose: Returns the larger of two numbers.
Example:
int larger = max(10, 20);
abs(x)
Purpose: Returns the absolute value of a number.
Example:
int absolute = abs(-5);
sqrt(x)
Purpose: Calculates the square root of a number.
Example:
float root = sqrt(16);
pow(base, exponent)
Purpose: Raises a number to a given power.
Example:
float result = pow(2, 3); // 2 raised to the power of 3
sin(angle)
Purpose: Calculates the sine of an angle (in radians).
Example:
float sineValue = sin(PI / 2);
cos(angle)
Purpose: Calculates the cosine of an angle (in radians).
Example:
float cosineValue = cos(PI);
tan(angle)
Purpose: Calculates the tangent of an angle (in radians).
Example:
float tanValue = tan(PI / 4);
lowByte(x)
Purpose: Extracts the low byte of a two-byte number.
Example:
byte lower = lowByte(0xABCD);
highByte(x)
Purpose: Extracts the high byte of a two-byte number.
Example:
byte higher = highByte(0xABCD);
bitRead(value, bit)
Purpose: Reads a specific bit of a number.
Example:
int bitValue = bitRead(0b1010, 2); // Read bit 2
bitWrite(value, bit, bitValue)
Purpose: Writes a specific bit of a number.
Example:
bitWrite(x, 1, 1); // Set bit 1 of x to 1
bitSet(value, bit)
Purpose: Sets a specific bit of a number to 1.
Example:
bitSet(x, 1); // Set bit 1 to 1
bitClear(value, bit)
Purpose: Clears a specific bit of a number (sets it to 0).
Example:
bitClear(x, 1); // Clear bit 1
bit(bit)
Purpose: Returns the value of a specific bit.
Example:
byte myBit = bit(3); // Returns 0b1000
