Simon memory game

Parts in this circuit

Wiring, pin by pin

Red = 5 V, orange = 3.3 V, black = GND, other colours = signals. “Pin” is the position on the 40-pin header; the GPIO number is what the code uses. Power the Pi from a 5.1 V supply and wire with the power off.

Python code (gpiozero)

from gpiozero import LED, Button, Buzzer
from random import choice
from time import sleep

leds = [LED(17), LED(27), LED(22), LED(23)]
buttons = [Button(5), Button(6), Button(13), Button(19)]
buzzer = Buzzer(24)

def flash(i):
    leds[i].on()
    buzzer.on()
    sleep(0.4)
    leds[i].off()
    buzzer.off()
    sleep(0.2)

def wait_for_choice():
    while True:
        for i in range(4):
            if buttons[i].is_pressed:
                leds[i].on()
                while buttons[i].is_pressed:
                    sleep(0.02)
                leds[i].off()
                return i
        sleep(0.02)

sequence = []
while True:
    sequence.append(choice([0, 1, 2, 3]))      # one new random step
    print("Round", len(sequence), "- watch!")
    sleep(0.6)
    for i in sequence:
        flash(i)
    print("Your turn")
    for i in sequence:
        if wait_for_choice() != i:
            print("Wrong! You reached round", len(sequence))
            buzzer.beep(0.5, 0.1, n=1)
            sequence = []
            sleep(2)
            break
    else:
        print("Correct!")
        sleep(0.8)

How the code works

• leds and buttons are lists. Index 0 is red, 1 is green, 2 is yellow, 3 is blue.
• choice() picks a random LED and the sequence list remembers every step so far.
• wait_for_choice() waits until a button is pressed and gives back its number.
• for ... else: the else part runs only when the loop finished without break, which means every step was right.

Parts to buy

The links open a search on each store, so you see what is in stock today. Check the model, voltage and price before you order.