Question

我正在尝试使用Python脚本将Raspberry Pi与USB RFID读卡器接口。作为记录，我的代码如下：

import serial, time, sys
import sqlite3 as lite

reader = "/dev/ttyUSB0"
ser = serial.Serial(reader, timeout=1)
print("Connected to RFID reader on:", reader)

try:
    while True:
        thetime = time.strftime("%Y-%m-%d %a %H:%M:%S", time.localtime())
        ser.flushInput() # flush any extra data from the serial port
        rfid_data = ser.readline().strip()

        if len(rfid_data) > 0:
            rfid_data = rfid_data[1:11]
            print("Card scanned", rfid_data)


        else:
            print("Card not found")

except:
    print("Unexpected error")

finally:
    ser.close()

此刻，我实际上收到了多个错误。我相信我不会用自己的语言来尽力解释它，而是确保以下片段对您中的大多数人更加有用。

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 275, in open
    self.fd = os.open(self.portstr, os.O_RDWR|os.O_NOCTTY|os.O_NONBLOCK)
FileNotFoundError: [Errno 2] No such file or directory: '/dev/ttyUSB0'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pi/Desktop/Alex Panagis/rfidtestfinal.py", line 5, in <module>
    ser = serial.Serial(reader, timeout=1)
  File "/usr/lib/python3/dist-packages/serial/serialutil.py", line 261, in __init__
    self.open()
  File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 278, in open
    raise SerialException("could not open port %s: %s" % (self._port, msg))
serial.serialutil.SerialException: could not open port /dev/ttyUSB0: [Errno 2] No such file or directory: '/dev/ttyUSB0'

对于解决此问题的任何帮助，我们深表感谢：）

没有这样的文件或目录：'/ dev / ttyUSB0'

0 个答案: