Announcements

• Exam grades and solutions have been posted on moodle
  • let me know if you can't see the comments, which clarify the points breakdown for each problem
• Homework 5 is due next Tuesday at 11:40am EDT.
• Plan this week:
  • We'll be doing a project this week: creating a music and light show on the Circuit Playground (Tues.) that is responsive to input from a sensor (Thurs.).
  • Be creative with this assignment! You'll submit a video at the end of the week along with your code, and there will be a space to optionally share the video with the class.
• Office hours and wizard sessions:
  • Delano: Wednesdays at 3pm-5pm EDT (same zoom link as lecture), or by appointment
  • Cheever: check his schedule
  • Ruether: by appointment Wednesdays 10am-12pm, Thursdays 3pm-5pm EDT (link)
  • Wizard sessions: Sunday 1-3pm EDT, Monday 7-9pm EDT (zoom link on moodle)

Learning Objectives and Outcomes

In this lecture, you will...

• listen to a short lecture introducing the concept of arrays and strings
• implement a song of your choosing using arrays and CircuitPlayground.playTone()
• create a password required for your song to play

By the end of this lecture, you should be able to...

• initialize arbitrary arrays and strings
• step through and access each element in an array using a for loop
• compare and concatenate strings

In Class Work

Introduction to Arrays

For this class, we will begin looking at new ways of organizing variables: arrays. Arrays are lists of elements of the same type. We can use them to keep track of many different variables at one time. Let's illustrate this with a series of examples:

#include <Adafruit_CircuitPlayground.h>

int c4 = 261; // frequency in hz
int g4 = 392;
int a4 = 440;

int noteDur = 200;

void setup() {
  CircuitPlayground.begin();
  CircuitPlayground.playTone(c4, noteDur); // frequency, duration (Hz, ms)
  CircuitPlayground.playTone(c4, noteDur);
  CircuitPlayground.playTone(g4, noteDur);
  CircuitPlayground.playTone(g4, noteDur);
  CircuitPlayground.playTone(a4, noteDur);
  CircuitPlayground.playTone(a4, noteDur);
  CircuitPlayground.playTone(g4, noteDur);
}

void loop() {
}

#include <Adafruit_CircuitPlayground.h>

int notes[3] = {261, 392, 440};

int noteDur = 200;

void setup() {
  CircuitPlayground.begin();
  CircuitPlayground.playTone(notes[0], noteDur);
  CircuitPlayground.playTone(notes[0], noteDur);
  CircuitPlayground.playTone(notes[1], noteDur);
  CircuitPlayground.playTone(notes[1], noteDur);
  CircuitPlayground.playTone(notes[2], noteDur);
  CircuitPlayground.playTone(notes[2], noteDur);
  CircuitPlayground.playTone(notes[1], noteDur);
}

void loop() {
}