Blinking LED

int led = 13;
void setup()
{
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);
}

void loop()
{
  digitalWrite(led, HIGH);
  delay(1000);
  digitalWrite(led, LOW);
  delay(1000);
}

All LEDS blinking

int led1 = 13;
int led2 = 12;
int led3 = 11;
int led4 = 10;

void setup()
{
  // initialize the digital pin as an output.
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
}

void loop()
{
  digitalWrite(led1, HIGH);
  digitalWrite(led2, HIGH);
  digitalWrite(led3, HIGH);
  digitalWrite(led4, HIGH);
  delay(1000);
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  digitalWrite(led4, LOW);
  delay(1000);
}

Switches example

const byte LED[] = {13, 12, 11, 10};
#define BUTTON1 A1
#define BUTTON2 A2

void setup()
{
  // initialize the digital pin as an output.
  /* Set each pin to outputs */
  pinMode(LED[0], OUTPUT);
  pinMode(LED[1], OUTPUT);
  pinMode(LED[2], OUTPUT);
  pinMode(LED[3], OUTPUT);
}

void loop()
{
  if (!digitalRead(BUTTON1))
  {
    digitalWrite(LED[0], HIGH);
    digitalWrite(LED[1], HIGH);
    digitalWrite(LED[2], HIGH);
    digitalWrite(LED[3], HIGH);
  }
  if (!digitalRead(BUTTON2))
  {
    digitalWrite(LED[0], LOW);
    digitalWrite(LED[1], LOW);
    digitalWrite(LED[2], LOW);
    digitalWrite(LED[3], LOW);
  }
}

Potentiometer 1

#define Pot1 0
void setup()
{
  Serial.begin(9600);
}
void loop()
{
  Serial.print(“Potentiometer reading: “);
  Serial.println(analogRead(Pot1));
  /* Wait 0.5 seconds before reading again */
  delay(500);
}

Pot and led

const byte LED[] = {13, 12, 11, 10};
#define Pot1 0
void setup()
{
  Serial.begin(9600);
  // initialize the digital pin as an output.
  /* Set each pin to outputs */
  pinMode(LED[0], OUTPUT);
  pinMode(LED[1], OUTPUT);
  pinMode(LED[2], OUTPUT);
  pinMode(LED[3], OUTPUT);
}

void loop()
{
  int PotValue;
  //Serial.print(“Potentiometer reading: “);
  PotValue = analogRead(Pot1);
  /* Wait 0.5 seconds before reading again */
  if (PotValue < 400)
  {
    digitalWrite(LED[0], LOW);
    digitalWrite(LED[1], LOW);
    digitalWrite(LED[2], LOW);
    digitalWrite(LED[3], LOW);
    Serial.print(“Potentiometer: “);
    Serial.println(PotValue);
  }
  else
  {
    digitalWrite(LED[0], HIGH);
    digitalWrite(LED[1], HIGH);
    digitalWrite(LED[2], HIGH);
    digitalWrite(LED[3], HIGH);
    Serial.print(“Potentiometer: “);
    Serial.println(PotValue);
  }
  delay(500);
}

Segment display

/* Define shift register pins used for seven segment display */
#define LATCH_DIO 4
#define CLK_DIO 7
#define DATA_DIO 8

/* Segment byte maps for numbers 0 to 9 */
const byte SEGMENT_MAP[] = {0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0X80, 0X90};
/* Byte maps to select digit 1 to 4 */
const byte SEGMENT_SELECT[] = {0xF1, 0xF2, 0xF4, 0xF8};

void setup ()
{
  /* Set DIO pins to outputs */
  pinMode(LATCH_DIO, OUTPUT);
  pinMode(CLK_DIO, OUTPUT);
  pinMode(DATA_DIO, OUTPUT);
}

/* Main program */
void loop()
{
  /* Update the display with the current counter value */
  WriteNumberToSegment(0 , 0);
  WriteNumberToSegment(1 , 1);
  WriteNumberToSegment(2 , 2);
  WriteNumberToSegment(3 , 3);
}

/* Write a decimal number between 0 and 9 to one of the 4 digits of the display */
void WriteNumberToSegment(byte Segment, byte Value)
{
  digitalWrite(LATCH_DIO, LOW);
  shiftOut(DATA_DIO, CLK_DIO, MSBFIRST, SEGMENT_MAP[Value]);
  shiftOut(DATA_DIO, CLK_DIO, MSBFIRST, SEGMENT_SELECT[Segment] );
  digitalWrite(LATCH_DIO, HIGH);
}

Read pot and display value on display

/* Define shift register pins used for seven segment display */

#define LATCH_DIO 4
#define CLK_DIO 7
#define DATA_DIO 8
#define Pot1 0

/* Segment byte maps for numbers 0 to 9 */
const byte SEGMENT_MAP[] = {0xC0, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0X80, 0X90};
/* Byte maps to select digit 1 to 4 */
const byte SEGMENT_SELECT[] = {0xF1, 0xF2, 0xF4, 0xF8};

void setup ()
{
  Serial.begin(9600);
  /* Set DIO pins to outputs */
  pinMode(LATCH_DIO, OUTPUT);
  pinMode(CLK_DIO, OUTPUT);
  pinMode(DATA_DIO, OUTPUT);
}

/* Main program */
void loop()
{
  int PotValue;
  PotValue = analogRead(Pot1);
  Serial.print(“Potentiometer: “);
  Serial.println(PotValue);
  /* Update the display with the current counter value */
  WriteNumberToSegment(0 , PotValue / 1000);
  WriteNumberToSegment(1 , (PotValue / 100) % 10);
  WriteNumberToSegment(2 , (PotValue / 10) % 10);
  WriteNumberToSegment(3 , PotValue % 10);
}

/* Write a decimal number between 0 and 9 to one of the 4 digits of the display */
void WriteNumberToSegment(byte Segment, byte Value)
{
  digitalWrite(LATCH_DIO, LOW);
  shiftOut(DATA_DIO, CLK_DIO, MSBFIRST, SEGMENT_MAP[Value]);
  shiftOut(DATA_DIO, CLK_DIO, MSBFIRST, SEGMENT_SELECT[Segment] );
  digitalWrite(LATCH_DIO, HIGH);
}