Program your Raspberry Pi Zero 2 W (with CircuitPython) without OS.

code.py

"""
  Program your Raspberry Pi Zero 2 W (with CircuitPython) without OS.
  
  Items:
  - Raspberry Pi Zero 2 W
    https://my.cytron.io/p-raspberry-pi-zero-2-w-wch
  - MakerDisk microSD Card
    https://my.cytron.io/p-raspberry-pi-approved-makerdisk-microsd-with-rpi-os
  - Maker pHAT
    https://my.cytron.io/p-maker-phat-simplifying-raspberry-pi-for-education
  - USB Micro B Cable
    https://my.cytron.io/p-usb-micro-b-cable
  - 3D Printing products
    https://my.cytron.io/c-3d-modeling
  
  References:
  - https://circuitpython.org/board/raspberrypi_zero2w/
  
  Last update: 1 Mar 2022
"""

import time
import board
import digitalio

print("CircuitPython (without OS) on RPi Zero 2 W")

led1 = digitalio.DigitalInOut(board.D17)
led1.direction = digitalio.Direction.OUTPUT
led2 = digitalio.DigitalInOut(board.D18)
led2.direction = digitalio.Direction.OUTPUT
led3 = digitalio.DigitalInOut(board.D27)
led3.direction = digitalio.Direction.OUTPUT
led4 = digitalio.DigitalInOut(board.D22)
led4.direction = digitalio.Direction.OUTPUT
led5 = digitalio.DigitalInOut(board.D25)
led5.direction = digitalio.Direction.OUTPUT
led6 = digitalio.DigitalInOut(board.D12)
led6.direction = digitalio.Direction.OUTPUT
led7 = digitalio.DigitalInOut(board.D13)
led7.direction = digitalio.Direction.OUTPUT
led8 = digitalio.DigitalInOut(board.D19)
led8.direction = digitalio.Direction.OUTPUT

sw1 = digitalio.DigitalInOut(board.D21)
sw1.direction = digitalio.Direction.INPUT
sw2 = digitalio.DigitalInOut(board.D16)
sw2.direction = digitalio.Direction.INPUT
sw3 = digitalio.DigitalInOut(board.D20)
sw3.direction = digitalio.Direction.INPUT

buzzer = digitalio.DigitalInOut(board.D26)
buzzer.direction = digitalio.Direction.OUTPUT

NONE = 0
INCREASE = 1
DECREASE = 2
ALL_OFF = 9
ALL_ON = 10

def beep(times, seconds):
    for x in range(times):
        buzzer.value = True
        time.sleep(seconds)
        buzzer.value = False
        time.sleep(seconds)

def led(led_number):
    if led_number == 1 or led_number == ALL_ON:
        led1.value = True
    else:
        led1.value = False
    if led_number == 2 or led_number == ALL_ON:
        led2.value = True
    else:
        led2.value = False
    if led_number == 3 or led_number == ALL_ON:
        led3.value = True
    else:
        led3.value = False
    if led_number == 4 or led_number == ALL_ON:
        led4.value = True
    else:
        led4.value = False
    if led_number == 5 or led_number == ALL_ON:
        led5.value = True
    else:
        led5.value = False
    if led_number == 6 or led_number == ALL_ON:
        led6.value = True
    else:
        led6.value = False
    if led_number == 7 or led_number == ALL_ON:
        led7.value = True
    else:
        led7.value = False
    if led_number == 8 or led_number == ALL_ON:
        led8.value = True
    else:
        led8.value = False

mode = NONE
led_position = 0

led(ALL_ON)
beep(1, 0.1)
led(ALL_OFF)

while True:
    if sw1.value == False and mode != DECREASE:
        beep(2, 0.07)
        mode = DECREASE
    elif sw2.value == False and mode != INCREASE:
        beep(2, 0.07)
        mode = INCREASE
    elif sw3.value == False and mode != NONE:
        beep(1, 0.07)
        mode = NONE
    if mode == INCREASE:
        if led_position < 8:
            led_position = led_position + 1
        else:
            led_position = 0
    elif mode == DECREASE:
        if led_position > 0:
            led_position = led_position - 1
        else:
            led_position = 8
    led(led_position)

    time.sleep(0.05)