Class notes

void setup() {
  pinMode(2, OUTPUT);
}

void loop() {
  // turn LED on
  digitalWrite(2, HIGH);
  // wait a sec
  delay(500); //msec
  // turn LED off
  digitalWrite(2, LOW);
  // wait a sec
  delay(500); 
}

Assignment

Reading & Question:

If we could calculate the voltage from printing the input in Arduino, do we still need the meters? Would the readings in Arduino be more accurate?

Lab: Digital Input and Output with an Arduino

Red, yellow and green light controlled by 2 buttons.

void setup() {
  pinMode(2, INPUT); //yellow button
  pinMode(3, INPUT); //green button
  pinMode(4, OUTPUT); //red LED
  pinMode(5, OUTPUT); //yellow LED
  pinMode(6, OUTPUT); //green LED
}

void loop() {
  //if no button is pushed, only the red LED blinks
  if (digitalRead(2) == LOW && digitalRead(3) == LOW) {
    delay(500);
    digitalWrite(4, HIGH);
    delay(500);
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
  }
 //if yellow button is pushed, only the yellow LED will light
  else if (digitalRead(2) == HIGH && digitalRead(3) == LOW) {
    digitalWrite(4, LOW);
    digitalWrite(5, HIGH);
    digitalWrite(6, LOW);
  }
//if green button is pushed, only the green LED will light
else if (digitalRead(2) == LOW && digitalRead(3) == HIGH) {
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    digitalWrite(6, HIGH); 
  }
}

IMG_7636.MOV

Lab: Analog In with an Arduino

Red LED dims when the potentiometer is turned down, green LED does the opposite

void setup() {
  Serial.begin(9600);
  pinMode(9, OUTPUT); //red LED
  pinMode(2, OUTPUT); //green LED
}

void loop() {
  int analogValue;
  int brightnessRed;
  int brightnessGreen;

  analogValue = analogRead(A0);

  //red LED is brighter when potentiometer is turned up (less R)
  brightnessRed = analogValue / 4;
  analogWrite(9, brightnessRed);

  //green LED is dimmer when potentiometer is turned up (less R)
  brightnessGreen = 1023 / 4 - analogValue / 4;
  analogWrite(2, brightnessGreen);
}

IMG_7639.MOV