Part 1: Digital I/O with LED’S

I started by calculating what resistor values I would need for the LED’S using Ohm’s Law:

The closest resistor value to 65Ω was 47Ω, so I used that one. I then hooked up the power to the arduino board and originally accidentally wired the switches with the 47Ω resistors, but as I was testing the first LED that I hooked up I noticed that it turning on only sometimes. I realized what the problem was and fixed that so that the switches were hooked up with 10kΩ resistors instead. After this the LED was working correctly, so I added the second LED and changed the code so they had different colors when the different buttons were pressed. I then changed it so when both the buttons were pressed at the same time, it flashed both of them one at a time and then turned them both on.

int led1 = 21;
int button1 = 3;

int led2 = 20;
int button2 = 2;


void setup() {
  // put your setup code here, to run once:
  pinMode(led1,OUTPUT);
  pinMode(button1,INPUT);

  pinMode(led2,OUTPUT);
  pinMode(button2,INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int buttonState1 = digitalRead(button1);
  int buttonState2 = digitalRead(button2);

  
  if (buttonState1 == HIGH && buttonState2 == LOW){
    digitalWrite(led1,HIGH);
  }else{
    digitalWrite(led1,LOW);
  }

    if (buttonState2 == HIGH && buttonState1 == LOW){
    digitalWrite(led2,HIGH);
  }else{
    digitalWrite(led2,LOW);
  }

  if (buttonState1 == HIGH && buttonState2 == HIGH){
    digitalWrite(led1,HIGH);
    delay(250);
    digitalWrite(led1,LOW);
    delay(100);
    digitalWrite(led1,HIGH);
    delay(250);
    digitalWrite(led1,LOW);
    delay(250);
    digitalWrite(led2,HIGH);
    delay(250);
    digitalWrite(led2,LOW);
    delay(100);
    digitalWrite(led2,HIGH);
    delay(250);
    digitalWrite(led2,LOW);
    delay(250);
    digitalWrite(led1,HIGH);
    digitalWrite(led2,HIGH);
    delay(250);
    digitalWrite(led1,LOW);
    digitalWrite(led2,LOW);
    delay(250);
  }
}

Part 2: Digital I/O with a Programmable LED Strip

Since I had my wiring all set up for LED’S, it was really easy to swap the LED’s with my LED strip. I started by soldering my neopixel strip with 3 wires, one for power, one for ground, and one for connecting it to the arduino/circut. I attached it to my board then ran the sample program to make sure that my LED strip was hooked up correctly. Below is also the circut for this LED strip.

I then wrote code that used the buttons to change the output of the LED strips, where when I would press the first one it changed all the even pixels on to a blue color, and when I would press the second button it changed all the odd pixels on to a purple color. When I would press both of them at the same time it flashes on all the even pixels and then all the odd pixels.

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif

//define the digital pin that the LED strip is connected to
#define PIN 20

//button pins
int button1 = 3;
int button2 = 2;


Adafruit_NeoPixel strip = Adafruit_NeoPixel(5, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  strip.begin();
  strip.show(); 

  pinMode(button1,INPUT);
  pinMode(button2,INPUT);

  Serial.begin(9600);
}

void loop() {

  int buttonState1 = digitalRead(button1);
  int buttonState2 = digitalRead(button2);


    if (buttonState1 == HIGH && buttonState2 == LOW){
    //even pixels on
    Serial.println("reading red");
    for(uint16_t i=0; i<strip.numPixels(); i+=2) {
      strip.setPixelColor(i, 16, 130, 59);
  }
    strip.show();
  }else{
    //off
    for(uint16_t i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, 0, 0, 0);  
  }
    strip.show();
  }

  if(buttonState1 == LOW && buttonState2 == HIGH) {
  //odd pixels on 
  for(uint16_t i = 1; i<strip.numPixels(); i+=2) {
    strip.setPixelColor(i, 69, 16, 130);
  }
  strip.show();
 }
 else {
   for(uint16_t i=0; i<strip.numPixels(); i++) {
     strip.setPixelColor(i,0,0,0);
   }
  strip.show();
 }

if(buttonState1 == HIGH && buttonState2 == HIGH) {
  for(uint16_t i=0; i<strip.numPixels(); i+=2) {
        strip.setPixelColor(i, 16, 130, 59); //set to purple, takes RGB vals 0-255
        strip.show();
        delay(500);
        strip.setPixelColor(i,0,0,0);
        strip.show();
        delay(500);
        strip.setPixelColor(i, 16, 130, 59); //set to purple, takes RGB vals 0-255
        strip.show();
        delay(500);
    }

    //turn off on one at a time
    for(uint16_t i=1; i<strip.numPixels(); i+=2) {
        strip.setPixelColor(i, 69, 16, 130); //set to purple, takes RGB vals 0-255
        strip.show();
        delay(500);
        strip.setPixelColor(i,0,0,0);
        strip.show();
        delay(500);
        strip.setPixelColor(i, 69, 16, 130); //set to purple, takes RGB vals 0-255
        strip.show();
        delay(500);
    }
  } 
}

Part 3: Soldered Breakout Boards

I chose to make a breakout board with a button and 2 LED’s. I did make a mistake though and chose purple LED’s which have too high voltage requirements so I couldn’t get both of them to light up even though they were both wired correctly. I removed the second one and re-soldered so it was just a button and one LED.