What are the types of inputs?

Digital and Analog

Is digital fun?

Yes!

Digital Output Reminder

Digital Input Example

int buttonPin = P1_3; // builtin button
int ledPin =  P1_6; // builtin light
int buttonState = 0;

void setup() {
  pinMode(ledPin, OUTPUT);      
  pinMode(buttonPin, INPUT_PULLUP); // input pin <-> ground 
}

void loop(){
  buttonState = digitalRead(buttonPin); // read the button
  if (buttonState == HIGH) { // if the button is up  
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW); 
  }
}
                    

Is analog cool too?

Yes, of course!

Demo

int PHOTO_RESISTOR = A7;
void setup()
{
  Serial.begin(9600);
  pinMode(PHOTO_RESISTOR, INPUT);
}
void loop()
{
  Serial.println(analogRead(PHOTO_RESISTOR));
  delay(500);
}
                        

Analog Pins

Are those LEDs made of magic?

Yes*

*No

Schematic

How can this be useful?

Logic with infrared

int PHOTO_RESISTOR = A7;
int LED = P1_6;
int THRESHOLD = 1;
int sensorReading = 0;
void setup()
{
  pinMode(PHOTO_RESISTOR, INPUT);
  pinMode(LED, OUTPUT);
}
void loop()
{
  sensorReading = analogRead(PHOTO_RESISTOR);
  if(sensorReading > THRESHOLD) {
    digitalWrite(LED, HIGH);
  } else {
    digitalWrite(LED, LOW);
  }
}
                        

What are we doing this week?

Traffic Light

Make your traffic light change if the infrared sensor is tripped.