doorbell-esp32-micropython/dfplayer.py

import utime
from machine import UART, Timer

IDLE = 0
PAUSED = 1
PLAYING = 2


class Player:
    def __init__(self, pin_TX, pin_RX):
        self.uart = UART(1, 9600, tx=pin_TX, rx=pin_RX)
        self.cmd(0x3F)  # send initialization parametres
        self._fadeout_timer = Timer(-1)

        self._volume = 5
        self._max_volume = 15
        self._fadeout_speed = 0
        
        self.current_folder = False
        
        self.volume(self._volume)

    def cmd(self, command, parameter=0x00):
        query = bytes([0x7e, 0xFF, 0x06, command,
                       0x00, 0x00, parameter, 0xEF])
        self.uart.write(query)
        
    def cmd2(self, command, par1=False, par2=False):

        #print("Folder: " + str(par1) + ", Track: " + str(par2))
        if par1 and par2:
            query1 = bytes([0x7e, 0xFF, 0x06, command, 0x00])
            query2 = bytes([par1])
            query3 = bytes([par2])
            query4 = bytes([0xEF])
            self.uart.write(query1)
            self.uart.write(query2)
            self.uart.write(query3)
            self.uart.write(query4)

    def _fade_out_process(self, timer):
        new_volume = self._volume - self._fadeout_speed
        
        if new_volume <= 0:
            print("fadeout finished")
            new_volume = 0
            self._fadeout_timer.deinit()
            self.stop()
            new_volume = self._max_volume # reset volume to max 
        self.volume(new_volume)

    # playback

    def play(self, track_id=False):
        self.play_from_folder(self.current_folder, track_id)
            
    def play_from_folder(self, folder_id=False, track_id=False):
        if isinstance(folder_id, int):
            self.current_folder = folder_id
        elif isinstance(self.current_folder, int):
            folder_id = self.current_folder
        else:
            folder_id = 1
            self.current_folder = folder_id
        
        if not track_id:
            track_id = 3
        elif track_id == 'next':
            self.cmd(0x01)
        elif track_id == 'prev':
            self.cmd(0x02)

        self.cmd2(0x0F, folder_id, track_id)
        #self.cmd2(command=0x0F, par1=1, par2=3)

    def pause(self):
        self.cmd(0x0E)

    def resume(self):
        self.cmd(0x0D)

    def stop(self):
        self.cmd(0x16)

    def fadeout(self, fadeout_ms=1000):
        # more than 500ms and less than 3000ms
        fadeout_ms = int(sorted([500, fadeout_ms, 3000])[1])
        fade_out_step_ms = 100
        self._fadeout_speed = self._volume * \
            fade_out_step_ms / fadeout_ms  # ten steps per second
        self._fadeout_timer.init(
            period=fade_out_step_ms, callback=self._fade_out_process)

    def loop_track(self, track_id):
        self.cmd(0x08, track_id)

    def loop(self):
        self.cmd(0x19)

    def loop_disable(self):
        self.cmd(0x19, 0x01)

    # volume control

    def volume_up(self):
        self._volume += 1
        self.cmd(0x04)

    def volume_down(self):
        self._volume -= 1
        self.cmd(0x05)

    def volume(self, volume=False):
        if volume:
            self._volume = int(sorted([0, volume, self._max_volume])[1])
            #print("volume", self._volume)
            self.cmd(0x06, self._volume)
        
        return self._volume

    # hardware

    def module_sleep(self):
        self.cmd(0x0A)

    def module_wake(self):
        self.cmd(0x0B)

    def module_reset(self):
        self.cmd(0x0C)