Don't overvolt it.

I’ll be honest, I’ve been having a little trouble coming up with ideas for these labs. I ended up tinkering with a lot of different sensors and outputs (photo resistor, temperature sensor, servo) and finally settled on getting a handle on how the RGB LED works. Total time, about 4 hours, but that was going through and tinkering with a few different circuits. 

Code: 

int potpin = 2;              // POT connected to digital pin 2 - pos/neg are left and right connections on POT

int rpin = 9;                // Red
int gpin = 10;               // Green
int bpin = 11;               // Blue
float h;                     // hue range
int h_int;                   // Hue color
int r = 0, g = 0, b = 0;           // Default RGB values

int val = 0;                   // Set POT value to default 0

void h2rgb(float h, int& R, int& G, int& B); // Instantiate h2rgb and it's variables  a.k.a  Hue to RGB

void setup()                   
{
  Serial.begin(9600);          // Begin the output of data to serial
}


void loop()                     
{
  val = analogRead(potpin);    // Read the pin and display the value
 h = ((float)val)/1024;       // Get the range. pot value / 1024

  h_int = (int) 360*h;         // Get the color hue by multiplying by 360

  h2rgb(h,r,g,b);              // Call the h2rgb function passing it the hue value

  Serial.print("POT value: ");
  Serial.print(val);           // Pot value
  Serial.print(" = hue of ");
  Serial.print(h_int);         // Color Hue value
  Serial.print(" degrees. RGB values: ");
  Serial.print(r);             // Red value
  Serial.print(" ");
  Serial.print(g);             // Green value
  Serial.print(" ");
  Serial.println(b);           // Blue value

  analogWrite(rpin, r);        // Changes red led
  analogWrite(gpin, g);        // Changes green led
  analogWrite(bpin, b);        // Changes blue led
  
}

void h2rgb(float h, int& R, int& G, int& B) {

  // Used HSV --> RGB function
  // HSV - Hue, Saturation, Value
  // RGB - Red, Green, Blue - example (255,255,255)
  // Function below does a bunch of math to convert HSV values to RGB
  int var_i;
  float S=1, V=1, var_1, var_2, var_3, var_h, var_r, var_g, var_b;

  if ( S == 0 )                       //HSV values = 0 ÷ 1
  {
    R = V * 255;
    G = V * 255;
    B = V * 255;
  }
  else
  {
    var_h = h * 6;
    if ( var_h == 6 ) var_h = 0;      //H must be < 1
    var_i = int( var_h ) ;            //Or ... var_i = floor( var_h )
    var_1 = V * ( 1 - S );
    var_2 = V * ( 1 - S * ( var_h - var_i ) );
    var_3 = V * ( 1 - S * ( 1 - ( var_h - var_i ) ) );

    if      ( var_i == 0 ) {
      var_r = V     ;
      var_g = var_3 ;
      var_b = var_1 ;
    }
    else if ( var_i == 1 ) {
      var_r = var_2 ;
      var_g = V     ;
      var_b = var_1 ;
    }
    else if ( var_i == 2 ) {
      var_r = var_1 ;
      var_g = V     ;
      var_b = var_3 ;
    }
    else if ( var_i == 3 ) {
      var_r = var_1 ;
      var_g = var_2 ;
      var_b = V     ;
    }
    else if ( var_i == 4 ) {
      var_r = var_3 ;
      var_g = var_1 ;
      var_b = V     ;
    }
    else                   {
      var_r = V     ;
      var_g = var_1 ;
      var_b = var_2 ;
    }

    R = (1-var_r) * 255;                  //RGB results = 0 ÷ 255
    G = (1-var_g) * 255;
    B = (1-var_b) * 255;
  }
}

PIxD Lab 2: Analogue Input

Code:

//FSR Pin

int forcePin = 0; //the analog pin the FSR is 

                  //connected to

//LED Pin

int ledPin = 9;   //the pin the LED is connected to

int ledPin2 = 11;

void setup()

{

  pinMode(ledPin, OUTPUT); //sets the led pin to output

  pinMode(ledPin2, OUTPUT); //sets second

}

 /*

 * loop() - this function will start after setup 

 * finishes and then repeat

 */

void loop()

{

 int forceLevel = analogRead(forcePin); //Read the

                                        // forcelevel

 forceLevel = map(forceLevel, 0, 900, 0, 255); 

         //adjust the value 0 to 900 to

         //span 0 to 255

 forceLevel = constrain(forceLevel, 0, 255);//make sure the 

                                           //value is between 

                                           //0 and 255

 analogWrite(ledPin, forceLevel);  //write the value

 analogWrite(ledPin2, 255 - forceLevel); //for second pin

}

PIxD Lab 1b: Variation on Digital Input/Output - Push Button to Toggle LEDs

const int LED = 13; // the pin for the LED
const int LED2 = 12; // the pin for the second LED
const int BUTTON = 7; //the input pin where the pusbutton is connected

int val = 0; //val will be used to store the state of the input pin
int old_val = 0; // this variable stores the previous value of "val"
int state = 0; // 0 = LED off and 1 = LED on

void setup () {
  pinMode(LED, OUTPUT); // tell Arduino LED is an output
  pinMode(LED2, OUTPUT); // tell Arduino LED2 is an output
  pinMode(BUTTON, INPUT); // and BUTTON is an input
}

void loop() {
  val = digitalRead(BUTTON); //read input value and store it

  //check if there was a transition
  if ((val == HIGH) && (old_val == LOW)) {
    state = 1 - state;
    delay(10);
  }

  old_val = val; // val is now old, store it

  if (state == 1) {
    digitalWrite(LED, HIGH); //turn LED on
    digitalWrite(LED2, LOW); //turn LED2 off

  } else {
    digitalWrite(LED, LOW); // turn LED off
    digitalWrite(LED2, HIGH); //turn LED2 on
  }
}

PIxD Lab 1A: Turn on LED while button is pressed


const int LED 13   // the pin for the LED
const int BUTTON 7 // the input pin where the pushbutton is connected


int val = 0;    // val will be used to store the state of the input pin

void setup() {
  pinMode(LED, OUTPUT);   // tell Arduino LED is an output
  pinMode(BUTTON, INPUT); // and BUTTON is an input
}

void loop(){
  val = digitalRead(BUTTON); // read input value and store it check whether the input is HIGH (button pressed)
  if (val == HIGH) {
    digitalWrite(LED, HIGH); // turn LED ON
  } else {
    digitalWrite(LED, LOW);
  }
}