Arduino IoT Tutorial 2 – Analog Input/Output

Components Required:

1. Arduino Uno 

2. Linux PC/Windows PC (Tested with Windows 10, Ubuntu 14.04 LTS)

3. USB cable A to B 

4. Breadboard

5. 5 mm LED 

6. 220 Ohms Resistor (colour code – Red, Red, Brown)

7. Potentiometer – 10K Ohm

8. Light Dependent Resistor (LDR)

9. Jumper Wires

Way to go ->

1. Connect Arduino Uno to PC via the USB cable.

2. Write the following sketches in the Arduino IDE, and upload them one by one.

LEDFade.ino

// These constants won't change.  They're used to give names

// to the pins used:

const int analogInPin = A0;  // Analog input pin that the potentiometer is attached to

const int analogOutPin = 9; // Analog output pin that the LED is attached to

int sensorValue = 0;        // value read from the pot

int outputValue = 0;        // value output to the PWM (analog out)

void setup() {

  // initialize serial communications at 9600 bps:

  Serial.begin(9600);

}

void loop() {

  // read the analog in value:

  sensorValue = analogRead(analogInPin);

  // map it to the range of the analog out:

  outputValue = map(sensorValue, 0, 1023, 0, 255);

  // change the analog out value:

  analogWrite(analogOutPin, outputValue);

  // print the results to the serial monitor:

  Serial.print("sensor = ");

  Serial.print(sensorValue);

  Serial.print("\t output = ");

  Serial.println(outputValue);

  // wait 2 milliseconds before the next loop

  // for the analog-to-digital converter to settle

  // after the last reading:  delay(2);

}

LDRBlink.ino

int sensorPin = A0;    // select the input pin for the potentiometer
int ledPin = 13;      // select the pin for the LED
int sensorValue = 0;  // variable to store the value coming from the sensor

void setup() {
  // declare the ledPin as an OUTPUT:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // read the value from the sensor:
  sensorValue = analogRead(sensorPin);
  // turn the ledPin on
  digitalWrite(ledPin, HIGH);
  // stop the program for <sensorValue> milliseconds:
  delay(sensorValue);
  // turn the ledPin off:
  digitalWrite(ledPin, LOW);
  // stop the program for for <sensorValue> milliseconds:
  delay(sensorValue);

}

Hardware Connections ->

1. LED and Potentiometer to Arduino Uno

2. LED and LDR to Arduino Uno