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);
}
}
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);
}