在指纹传感器 PYTHON 上没有输入 15 秒后退出指纹程序

Question

我有一个我自己无法解决的问题（我尝试了很多，time.time()但我从来没有解决我的问题）。如果 15 秒过去了，我希望我的程序退出并停止等待手指。如果有人知道如何在 python 中做到这一点，我会非常高兴和感激！非常感谢！问我是否有任何问题！代码在下面！import sysimport ossys.path.insert(0, '/home/pi/scripts')import subprocessimport lcddriverfrom time import *lcd = lcddriver.lcd()lcd.lcd_clear()import hashlibfrom pyfingerprint.pyfingerprint import PyFingerprint## Tries to initialize the sensortry:f = PyFingerprint('/dev/ttyUSB0', 57600, 0xFFFFFFFF, 0x00000000)if ( f.verifyPassword() == False ):    raise ValueError('The given fingerprint sensor password is wrong!')except Exception as e:lcd.lcd_display_string('Initialization failed!', 2)print('Exception message: ' + str(e))exit(1)## Gets some sensor informationprint('Currently used templates: ' + str(f.getTemplateCount()) +'/'+ str(f.getStorageCapacity()))## Tries to search the finger and calculate hashtry: f = PyFingerprint('/dev/ttyUSB0', 57600, 0xFFFFFFFF, 0x00000000)if ( f.verifyPassword() == False ):    raise ValueError('The given fingerprint sensor password is wrong!')except Exception as e:lcd.lcd_display_string('Initialization failed!', 2)print('Exception message: ' + str(e))exit(1)## Gets some sensor informationprint('Currently used templates: ' + str(f.getTemplateCount()) +'/'+ str(f.getStorageCapacity()))## Tries to search the finger and calculate hashtry:lcd.lcd_display_string(' Waiting for finger', 2)## Wait that finger is readwhile ( f.readImage() == False ):    pass## Converts read image to characteristics and stores it in charbuffer 1f.convertImage(0x01)## Searchs templateresult = f.searchTemplate()positionNumber = result[0]accuracyScore = result[1] if ( positionNumber == -1 ):    os.system('python access_denied.py')    exit(0) else:    lcd.lcd_clear()    lcd.lcd_display_string("  Finger accepted!", 2)    sleep(1.5)    lcd.lcd_clear()    os.system('python keypad.py')

Answer 1

你可以试试这个：

timeout = time.time() + 15 # 15s from now

while True:

   # do stuff

    end_time = time.time()

    if end_time > timeout or f.readImage():

        break

    else:

        time.sleep(0.25) # sleep to reduce CPU usage