Teddy love his stuffed elephant Paco and he feels very possessive about him. He hates to share. If you take Paco away, watch out!

Here’s the code that produced this:

const int buttonPin = 2; // the number of the pushbutton pin
const int ledRightEye = 9; // the number of the LED pins
const int ledLeftEye = 10;
int brightness = 0; // how bright the LED is
int fadeAmount = 5; // how many points to fade the LED by
int buttonState; // variable for reading the pushbutton status

void setup() {
pinMode(ledRightEye, OUTPUT);
pinMode(ledLeftEye, OUTPUT);
pinMode(buttonPin, INPUT);
}

void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

if (buttonState == HIGH) {
// set the brightness of the pins:
analogWrite(ledRightEye, brightness);
analogWrite(ledLeftEye, brightness);

// change the brightness for next time through the loop:
brightness = brightness + fadeAmount;

// reverse the direction of the fading at the ends of the fade:
if (brightness == 0 || brightness == 255) {
fadeAmount = -fadeAmount ;
}
// wait for 30 milliseconds to see the dimming effect
delay(3);
}else{
analogWrite(ledRightEye, 0);
analogWrite(ledLeftEye, 0);
}
}

But before I could even get to that I had to figure out a few things.

My first Arduino program and circuit was to use a button as input and when pressed an LED light would turn on as the output. Having come from somewhat of a development background, programming the Arduino was pretty straight forward. The hard part was figuring out where all these wires went. Eventually it started to make sense and I got it to work.

Here’s the code:

const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 13; // the number of the LED pin
int buttonState = 0; // variable for reading the pushbutton status

void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT);
}

void loop(){
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

if (buttonState == LOW) {
// turn LED on:
digitalWrite(ledPin, HIGH);
} else {
// turn LED off:
digitalWrite(ledPin, LOW);
}
}


Next I wanted to try to get the light to pulse. In trying to accomplished I realized with digitalRead and digitalWrite they only took values of HIGH and LOW, meaning on or off. I couldn’t vary the intensity of the light. I had to use analogRead and analogWrite

Here’s the code for this:

int brightness = 0; // how bright the LED is
int fadeAmount = 5; // how many points to fade the LED by
const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 9; // the number of the LED pin
int buttonState; // variable for reading the pushbutton status

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

void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

if (buttonState == LOW) {
// set the brightness of the LED:
analogWrite(ledPin, brightness);

// change the brightness for next time through the loop:
brightness = brightness + fadeAmount;

// reverse the direction of the fading at the ends of the fade:
if (brightness == 0 || brightness == 255) {
fadeAmount = -fadeAmount ;
}
// wait for 30 milliseconds to see the dimming effect
delay(30);
}else{
analogWrite(ledPin, 0);
}
}

Then as part of the assignment, we had to create a switch. When the button is pressed, one light would turn on and the other would turn off. And vice versa, when the button not pressed.

const int buttonPin = 2; // the number of the pushbutton pin
const int ledPinGreen = 9; // the number of the LED pin
const int ledPinRed = 10;
int buttonState; // variable for reading the pushbutton status

void setup() {
pinMode(ledPinGreen, OUTPUT);
pinMode(ledPinRed, OUTPUT);
pinMode(buttonPin, INPUT);
}

void loop() {
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);

if (buttonState == HIGH) {
// set the brightness of the pins:
digitalWrite(ledPinRed, HIGH);
digitalWrite(ledPinGreen, LOW);
}else{
digitalWrite(ledPinRed, LOW);
digitalWrite(ledPinGreen, HIGH);
}
}