使用Python通过序列读取不固定数量的字节

Question

我正在尝试从串行端口读取不固定数量的字节。我可以使用read读取固定数量的字节，放入的字节数大于实际存在的字节数，这将导致它永远等待。输入的字节数少于实际出现的字节数将裁剪掉某些字符。使用read_all，输出似乎为空。 Readline（）产生语法错误。我没有想法了，有什么想法吗？这是我的代码：

import time
import datetime
import serial
import os


# public variables
sensors = []  # list of sensor readings
wait = True
sensor_count = 10 # the zero based count of sensors


def pwr_solenoid(solenoid0=0, solenoid1=0, solenoid2=0, solenoid3=0):
    # Defaults are for low signal values

    # compile output
    output = '9{solenoid0}{solenoid1}{solenoid2}{solenoid3}' \
        .format(solenoid0=solenoid0, solenoid1=solenoid1, solenoid2=solenoid2, solenoid3=solenoid3).encode()

    with serial.Serial('/dev/ttyACM0', baudrate=9600) as ser:
        print("created connection to '/dev/ttyACM0'\n")
        print("going to send:\t'{}'".format(output))
        ser.write(output)
        ser.reset_output_buffer()

        # for testing to console
        print("Value sent to the uC:\t'{}'".format(output.decode()))

        # ***** READ from UART *****

        #ser.in_waiting >= 12:
        raw = ser.read(16)
        print("printing raw value of ser.read(16)\n")
        print(raw)
        val = str(ser.read_all().decode()) # (3).decode()[2:])
        #printing val
        print("\n printing val using read_all \n")
        print(val)
        val1 = raw.decode()
        #printing val of raw.decode()
        print("\n pringting val of raw.decode() \n")
        print(val1)
        # print("printing value of ser.readline()\n"
        # serreadlin = ser.readline() This line generates an error cannot use readline() 
        # print(serreadlin)
        # print("printing val\n")
        # print(val)
        # exit()

Answer 1

您可以使用：

import serial
import time

ser = serial.Serial(port='/dev/ttyUSB0', baudrate=115200, timeout=1)

while True:
    val =  ser.readline().strip()
    if(val):
       print (val)