卡在python项目中

Question

I'm working on a project of my own, and I'm at a point where i don't know anymore what to do..

I'm trying to implement some sounds into my project where i press some tact. switches and they should make sounds.. I'm a complete newbie with python so i found a piece of code doing something similar...

import os
from time import sleep
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)
GPIO.setup(23, GPIO.IN)
GPIO.setup(24, GPIO.IN)
GPIO.setup(25, GPIO.IN)

while True:
    if (GPIO.input(23) == False):
        os.system('mpg123 -q binary-language-moisture-evaporators.mp3 &')
    if (GPIO.input(24) == False):
        os.system('mpg123 -q power-converters.mp3 &')
    if (GPIO.input(25)== False):
        os.system('mpg123 -q vader.mp3 &')
    sleep(0.1);

I want the 1st sound to run in a continuous loop while input(23)==false and if one of the other two buttons is pressed it stops the first one and plays the other, only once, and returns to checking if input(23)==false

I need this to be done to finish my project, but I don't have the need really to learn python from scratch (at least for now). at least some guidelines would be greatly appreciated.

Answer 1

How about this?

play = True
while True:

    if (GPIO.input(24) == False):
        play = False
        os.system('mpg123 -q power-converters.mp3 &')
    else:
        play = True

    if (GPIO.input(25)== False):
        play = False
        os.system('mpg123 -q vader.mp3 &')
    else:
        play = True

    if (play and GPIO.input(23) == False):
        os.system('mpg123 -q binary-language-moisture-evaporators.mp3 &')

    sleep(0.1);

Answer 2

This codes seems working (as I simulated it). You may need modify it to suite your need though. For example, if both 24 and 25 are pressed, which one should be played (24 takes precedence over 25 in the code).

import subprocess
from time import sleep
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)
GPIO.setup(23, GPIO.IN)
GPIO.setup(24, GPIO.IN)
GPIO.setup(25, GPIO.IN) 

proc1 = ''
proc2 = ''
proc3 = ''
while True:
    if GPIO.input(24) == False:
        if proc3:
            proc3.kill()
            proc3 = ''
        if proc2 and proc2.poll() is None:
            proc2.kill()
            proc2 = ''
        if not proc1 or proc1.poll() is not None:
            proc1 = subprocess.Popen(['mpg123','-q','power-converters.mp3'])
    elif GPIO.input(25) == False:
        if proc3:
            proc3.kill()
            proc3 = ''
        if proc1 and proc1.poll() is None:
            proc1.kill()
            proc1 = ''
        if not proc2 or proc2.poll() is not None:
            proc2 = subprocess.Popen(['mpg123','-q','vader.mp3'])
    elif GPIO.input(23) == False:
        if not (proc1 and proc1.poll() is None) and not (proc2 and proc2.poll() is None):
            if not proc3 or proc3.poll() is not None:
                proc3 = subprocess.Popen(['mpg123','-q','binary-language-moisture-evaporators.mp3'])
    elif proc3 and proc3.poll() is None:
        proc3.kill()
        proc3 = ''

    sleep(0.1)