Simon: Buttons and Notes

Part of the Projects section of Coddy's Arduino journey. Lesson 13 of 24.

Simon is a memory game: the board plays a pattern of coloured lights and notes, and you repeat it on the buttons. Each round the pattern grows by one, until you make a mistake. There are four colours, each with a button, an LED and a note.

With four of everything, arrays keep the sketch short. Entry 0 of every array is red, 1 is green, 2 is blue and 3 is yellow, so one number, i, names a colour everywhere:

const int ledPins[4] = {9, 10, 11, 12};
const int buttonPins[4] = {2, 3, 4, 5};
const int notes[4] = {262, 330, 392, 523};

A for loop checks all four buttons. Act at two moments: a button goes down (LOW now, HIGH last time) and comes back up (HIGH now, LOW last time). The array lastState keeps each button's last reading. Later steps count a press when the button comes back up. These buttons do not bounce, so the edge checks are enough.

Challenge

Medium

Make the four colours play:

in setup(), a for loop makes the LED pins outputs and the button pins INPUT_PULLUP
when button i goes down, light ledPins[i] and play notes[i] on pin 8
when it comes back up, turn the LED off and call noTone()

Press Run, play the buttons, then Check.

Try it yourself

// One entry per colour: red, green, blue, yellow
const int ledPins[4] = {9, 10, 11, 12};
const int buttonPins[4] = {2, 3, 4, 5};
const int notes[4] = {262, 330, 392, 523};  // C, E, G and high C
const int buzzerPin = 8;

int lastState[4] = {HIGH, HIGH, HIGH, HIGH};  // each button's last reading

void setup() {
  // LEDs are outputs, buttons are INPUT_PULLUP

}

void loop() {
  // for each button: when it goes down, light its LED and play its note;
  // when it comes back up, turn them off

}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

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