[经验分享] 【基于人脸识别的自动打卡健走计时系统】用多线程处理(二维码扫码+音频播放）

【基于人脸识别的自动打卡健走计时系统】 K210 MAIXBIT用二维码识别作为用户信息

基于之前设计的扫码二维码，然后提示音频播放的代码，再完善一下，考虑用线程将扫码任务和播放音频任务进行分开

（一）关于多线程

创建：audio_play_thread和qrcode_detect_thread

import _thread
import time

#---------------------------------------------------------------------------------------------------
clock = time.clock()
print(os.listdir("/"))

lcd.init()

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.set_vflip(1)
sensor.run(1)
sensor.skip_frames(30)

audio_state = 0
lock = _thread.allocate_lock()

_thread.start_new_thread(qrcode_detect_thread,("qrcodes detect thread",))
_thread.start_new_thread(audio_play_thread,("audio play thread",))

while True:
    pass

（二）创建二维码扫码

需要在线程中调用time.sleep()将时间切出给音频播放任务

import sensor
import image
import lcd
import time

#---------------------------------------------------------------------------------------------------
#二维码识别
def qrcode_detect_thread(name):
    global audio_state

    while True:
        img = sensor.snapshot()
        res = img.find_qrcodes()
        fps =clock.fps()

        if len(res) > 0:
            img.draw_string(2, 2, res[0].payload(), color=(0,128,0), scale=2)
            print(res[0].payload())
            lock.acquire()
            audio_state = 1
            print(lock.locked())
            lock.release()
            time.sleep_ms(200)
        else:
            lock.acquire()
            audio_state = 0
            print(lock.locked())
            lock.release()

        print("hello {}".format(name),"fps", fps)
        lcd.display(img)

（三）关于音频播放线程

关于音频播放线程何时执行，靠判断变量audio_state状态得到

# I2S 音频播放模块
import uos, os
from fpioa_manager import *
from Maix import I2S, GPIO
import audio

#---------------------------------------------------------------------------------------------------
# 音频播放
def audio_init():
    # register i2s(i2s0) pin
    fm.register(34, fm.fpioa.I2S0_OUT_D1, force=True)
    fm.register(35, fm.fpioa.I2S0_SCLK, force=True)
    fm.register(33, fm.fpioa.I2S0_WS, force=True)

    # init i2s(i2s0)
    wav_dev = I2S(I2S.DEVICE_0)
    print("i2s init")
    return wav_dev

def audio_play(wav_dev, file_path, volume):
    # init audio
    #player = audio.Audio(path="/sd/2.wav") #需要支持从SD卡读取音频文件
    player = audio.Audio(path=file_path)
    player.volume(volume)
    print("audio play init")

    # read audio info
    wav_info = player.play_process(wav_dev)

    # config i2s according to audio info
    wav_dev.channel_config(wav_dev.CHANNEL_1, I2S.TRANSMITTER, resolution=I2S.RESOLUTION_16_BIT,
                       cycles=I2S.SCLK_CYCLES_16, align_mode=I2S.RIGHT_JUSTIFYING_MODE)

    wav_dev.set_sample_rate(wav_info[1])

    # loop to play audio
    while True:
        ret = player.play()
        if ret == None:
            print("format error")
            break
        elif ret == 0:
            print("end")
            break
        time.sleep_us(20)
    player.finish()

def audio_play_thread(name):
    dev = audio_init()
    print("audio init")

    while True:

        lock.acquire()
        print(lock.locked())
        state = audio_state

        lock.release()

        print("hello {}".format(name))
        if (state == 1):
            print("audio play start...\r\n")
            audio_play(dev, "/sd/2.wav", 50) #识别成功
            print("audio play end...\r\n")
        #audio_play(dev, "/sd/2.wav", 50) #识别成功
        time.sleep(1)

基于之前设计的扫码二维码，然后提示音频播放的代码，再完善一下，考虑用线程将扫码任务和播放音频任务进行分开。看来项目快完工了。