DFPlayerとRaspberry Pi picoで作るシンプルな音楽プレーヤー：DFPlayerの制御は他プロジェクトでも使えるようにオリジナルのPythonライブラリにて実装

import machine
import utime

# --- DFPlayerの使い方 ---
# microSDカード直下に"mp3"という名称のフォルダを作成し"0001.mp3"のような連番でファイルを格納しておく。
# 第1引数でTXピン番号、第2引数でRXピン番号を指定する。
# 第3引数（オプション）でボリューム値を指定をする場合は、0〜30までの数値で指定する。デフォルト値は15。

THIS_VERSION = 1.0

class DFPlayer:

	def __init__(self, tx:int, rx:int, volume:int=15):
		self.uart = machine.UART(1, baudrate=9600, tx=machine.Pin(tx), rx=machine.Pin(rx))

		# sd初期化
		self._command(0x3F, 0x02)
		utime.sleep_ms(500)

		# volume設定
		self.set_volume(volume)

		print("DFPlayer initialized (ver.{})".format(THIS_VERSION))

	def _command(self, command, parameter=0x00):
		query = bytes([0x7e, 0xFF, 0x06, command, 0x00, 0x00, parameter, 0xEF])
		self.uart.write(query)

	# 以下、制御メソッド

	def set_volume(self, volume:int):
		self._command(0x06, volume)
		print("Volume: {}".format(volume))
		utime.sleep_ms(500)

	def play(self, num:int):
		self._command(0x12, num)
		print("Play: {}".format(num))
		utime.sleep_ms(500)

	def repeat(self):
		self._command(0x08)
		print("Repeat ON")
		utime.sleep_ms(500)

	def pause(self):
		self._command(0x0E)
		print("Pause")
		utime.sleep_ms(500)

	def resume(self):
		self._command(0x0D)
		print("Resume")
		utime.sleep_ms(500)

	def stop(self):
		self._command(0x16)
		print("Stop / Repeat OFF")
		utime.sleep_ms(500)

import machine
import utime
from DFPModule import DFPlayer

player = DFPlayer(8, 9, 20)

btn1 = machine.Pin(0, machine.Pin.IN, machine.Pin.PULL_UP)
btn2 = machine.Pin(4, machine.Pin.IN, machine.Pin.PULL_UP)
btn3 = machine.Pin(16, machine.Pin.IN, machine.Pin.PULL_UP)
btn4 = machine.Pin(20, machine.Pin.IN, machine.Pin.PULL_UP)
btn5 = machine.Pin(26, machine.Pin.IN, machine.Pin.PULL_UP)

ON = 0
OFF = 1

btn1_prev = OFF
btn2_prev = OFF
btn3_prev = OFF
btn4_prev = OFF
btn5_prev = OFF

pause = False
repeat = False

track = 1
max = 5

while True:
	btn1_state = btn1.value()
	btn2_state = btn2.value()
	btn3_state = btn3.value()
	btn4_state = btn4.value()
	btn5_state = btn5.value()

	# 次のトラックを再生
	if btn1_prev == OFF and btn1_state == ON:
		track += 1
		if track > max:
			track = 1
		player.play(track)

	# 前のトラックを再生
	if btn2_prev == OFF and btn2_state == ON:
		track -= 1
		if track < 1:
			track = max
		player.play(track)

	# 現在のトラックを再生。一時停止時は途中から再生
	if btn3_prev == OFF and btn3_state == ON:
		if pause == False:
			player.play(track)
		else:
			player.resume()
			pause = False

	# 一時停止
	if btn4_prev == OFF and btn4_state == ON:
		pause = True
		player.pause()

	# リピートON／リピートOFF（Stop）
	if btn5_prev == OFF and btn5_state == ON:
		if repeat == False:
			player.repeat()
			repeat = True
		else:
			player.stop()
			repeat = False

	btn1_prev = btn1_state
	btn2_prev = btn2_state
	btn3_prev = btn3_state
	btn4_prev = btn4_state
	btn5_prev = btn5_state

	utime.sleep_ms(1)