树莓派 python蜂鸣器播放音乐

python（树莓派蜂鸣器程序注释）

import RPi.GPIO as GPIO
import time

Buzzer = 11 #蜂鸣器接在第11管脚上

# 定义低中高频率
CL = [0, 131, 147, 165, 175, 196, 211, 248]		# Frequency of Low C notes

CM = [0, 262, 294, 330, 350, 393, 441, 495]		# Frequency of Middle C notes

CH = [0, 525, 589, 661, 700, 786, 882, 990]		# Frequency of High C notes

# 第一首歌谱子频率
song_1 = [	CM[3], CM[5], CM[6], CM[3], CM[2], CM[3], CM[5], CM[6], # Notes of song1
			CH[1], CM[6], CM[5], CM[1], CM[3], CM[2], CM[2], CM[3], 
			CM[5], CM[2], CM[3], CM[3], CL[6], CL[6], CL[6], CM[1],
			CM[2], CM[3], CM[2], CL[7], CL[6], CM[1], CL[5]	]
# 节奏
beat_1 = [	1, 1, 3, 1, 1, 3, 1, 1, 			# Beats of song 1, 1 means 1/8 beats
			1, 1, 1, 1, 1, 1, 3, 1, 
			1, 3, 1, 1, 1, 1, 1, 1, 
			1, 2, 1, 1, 1, 1, 1, 1, 
			1, 1, 3	]

song_2 = [	CM[1], CM[1], CM[1], CL[5], CM[3], CM[3], CM[3], CM[1], # Notes of song2
			CM[1], CM[3], CM[5], CM[5], CM[4], CM[3], CM[2], CM[2], 
			CM[3], CM[4], CM[4], CM[3], CM[2], CM[3], CM[1], CM[1], 
			CM[3], CM[2], CL[5], CL[7], CM[2], CM[1]	]

beat_2 = [	1, 1, 2, 2, 1, 1, 2, 2, 			# Beats of song 2, 1 means 1/8 beats
			1, 1, 2, 2, 1, 1, 3, 1, 
			1, 2, 2, 1, 1, 2, 2, 1, 
			1, 2, 2, 1, 1, 3 ]

# 一些初始化操作
def setup():
    GPIO.setwarnings(False)         # 先关掉警告，因为操作io口会有警告
    GPIO.setmode(GPIO.BOARD)		# Numbers GPIOs by physical location 树莓派有很多编码模式，这里采用GPIO编码模式
    GPIO.setup(Buzzer, GPIO.OUT)	# Set pins' mode is output Buzzer = 11 #蜂鸣器接在第11管脚上
    global Buzz						# Assign a global variable to replace GPIO.PWM
    Buzz = GPIO.PWM(Buzzer, 440)	# 440 is initial frequency.440HZ初试频率
    Buzz.start(50)					# Start Buzzer pin with 50% duty ration 

def loop():
	while True:
		print '\n    Playing song 1...'
		for i in range(1, len(song_1)):		# Play song 1
			Buzz.ChangeFrequency(song_1[i])	# Change the frequency along the song note
			time.sleep(beat_1[i] * 0.5)		# delay a note for beat * 0.5s 
		time.sleep(1)						# Wait a second for next song.

		print '\n\n    Playing song 2...'
		for i in range(1, len(song_2)):     # Play song 1
			Buzz.ChangeFrequency(song_2[i]) # Change the frequency along the song note
			time.sleep(beat_2[i] * 0.5)     # delay a note for beat * 0.5s

# 释放资源
def destory():
	Buzz.stop()					# Stop the buzzer
	GPIO.output(Buzzer, 1)		# Set Buzzer pin to High
	GPIO.cleanup()				# Release resource

if __name__ == '__main__':		# Program start from here
	setup()
	try:
		loop()
	except KeyboardInterrupt:  	# When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
		destory()