读取串行接口时的编码问题(我认为)

Question

我正试图通过P1接口读出我的智能电表。一些python脚本是张贴在网上这样做，我尝试了它们，但似乎得到一些部分垃圾我的串行接口(不完全-所以我的假设是串行设置是正确的，虽然。也因为我是从其他脚本中复制这个似乎是工作)。

当尝试使用cu命令读取接口时，它确实显示了正确的输出，所以我的硬件似乎可以工作。

我正在运行这个:Linux版本3.10.25+ (dc4@dc4-arm-01) (gcc版本4.7.2 20120731(预发布)(crossstool - ng Linaro -1.13.1+bzr2458 - Linaro gcc 2012.08)) #622 PREEMPT星期五1月3日18:41:00 GMT 2014

输出应该是这样的——通过以下方式检索:

命令:

cu -l /dev/ttyUSB0 -s 9600 --parity=none

---

/INTENTIONALLY ALTERED
0-0:96.1.1(39373936353532302020202020202020)
1-0:1.8.1(05090.742*kWh)
1-0:1.8.2(06618.743*kWh)
1-0:2.8.1(00000.000*kWh)
1-0:2.8.2(00000.000*kWh)
0-0:96.14.0(0001)
1-0:1.7.0(0000.71*kW)
1-0:2.7.0(0000.00*kW)
0-0:17.0.0(999*A)
0-0:96.3.10(1)
0-0:96.13.1()
0-0:96.13.0()
0-1:96.1.0(3238303131303038323033333632313132)
0-1:24.1.0(03)
0-1:24.3.0(140806220000)(2C)(60)(1)(0-1:24.2.0)(m3)
(03447.404)
0-1:24.4.0(1)
!

当我使用以下Python代码时:

# DSMR P1 uitlezen
# (c) 10-2012 - GJ - gratis te kopieren en te plakken
versie = "1.0"
import sys
import serial

##############################################################################
#Main program
##############################################################################
print ("DSMR P1 uitlezen",  versie)
print ("Control-C om te stoppen")
print ("Pas eventueel de waarde ser.port aan in het python script")
#Set COM port config
ser = serial.Serial()
ser.baudrate = 9600
ser.bytesize=serial.SEVENBITS
ser.parity=serial.PARITY_EVEN
ser.stopbits=serial.STOPBITS_ONE
ser.xonxoff=0
ser.rtscts=0
ser.timeout=20
ser.port="/dev/ttyUSB0"
#Open COM port
try:
    ser.open()
except:
    sys.exit ("Fout bij het openen van %s. Aaaaarch."  % ser.name)

#Initialize
#p1_teller is mijn tellertje voor van 0 tot 20 te tellen
p1_teller=0
while p1_teller < 20:
    p1_line=''
#Read 1 line van de seriele poort
    try:
        p1_raw = ser.readline()
        print str(p1_teller),':', p1_raw
    except:
        sys.exit ("Seriele poort %s kan niet gelezen worden. Aaaaaaaaarch." % ser.name )
    #p1_str=str(p1_raw)
    #p1_line=p1_str.strip()
# als je alles wil zien moet je de volgende line uncommenten
    #print (p1_line.encode('ascii','ignore'))
    p1_teller = p1_teller +1
#Close port and show status
try:
    ser.close()
except:
    sys.exit ("Oops %s. Programma afgebroken. Kon de seriele poort niet sluiten." % ser.name )

输出变成如下:

('DSMR P1 uitlezen', '1.0')
Control-C om te stoppen
Pas eventueel de waarde ser.port aan in het python script
0 : INTENTIONALLY ALTERED BUT ALSO WITH THE ? SYMBOLS IN THE ORIGINAL OUTPUT
1 : �
2 : 0-0:96.�.�(393�393635353�30�0�0�0�0�0�0�0�0��
3 : �-0:�.�.�(05090.�9����詍
4 : �-0:�.�.�(066��.��3���詍
5 : �-0:�.�.�(00000.000���詍
6 : �-0:�.�.�(00000.000���詍
7 : 0-0:96.��.0(000���
8 : �-0:�.�.0(0000.�0��ש�
9 : �-0:�.�.0(0000.00��ש�
10 : 0-0:��.0.0(999�A��
11 : 0-0:96.3.�0(���
12 : 0-0:96.�3.�(��
13 : 0-0:96.�3.0(��
14 : 0-�:96.�.0(3�3�303�3�30303�3�303333363�3�3�3���
15 : 0-�:��.�.0(03��
16 : 0-�:��.3.0(��0�06��0000�(�é(60�(��(0-�:��.�.0�(�3��
17 : (03���.�0���
18 : 0-�:��.�.0(���
19 : !�

所以在我的python输出中有很多字符，我预计这是一些编码问题。但不确定，不确定如何解决这个问题…因此，任何帮助都是感激的。

Answer 1

看起来您读取的字节可能仍然包含奇偶校验位，使它们成为无效字符。试着删除第8位:

p1_raw = ''.join(chr(ord(ch) & 0x7f) for ch in p1_raw)

Answer 2

这就是我最终修复它的方式-将尝试Ldevries方法....看起来很干净:

#
# MBSolget P1 Telegram Catch
#
version = "v1.00"
import sys
import os
import stat
import serial
import datetime
import locale
###############################################################################################################
# Main program
###############################################################################################################
#Initialize
p1_telegram  = False
p1_timestamp = ""
p1_teller    = 0
p1_log       = True
#Set COM port config
ser          = serial.Serial()
ser.baudrate = 9600
ser.bytesize = serial.EIGHTBITS
ser.parity   = serial.PARITY_NONE
ser.stopbits = serial.STOPBITS_ONE
ser.xonxoff  = 1
ser.rtscts   = 0
ser.timeout  = 30
ser.port     = "/dev/ttyUSB0"
#Show startup arguments
print ("MBSolget P1 Telegram Catch %s" % version)
print ("Control-C om af te breken")
print ("Poort: (%s)" % (ser.name) )
#Open COM port
try:
    ser.open()
except:
    sys.exit ("Fout bij het openen van poort %s. "  % ser.name)
while p1_log:
    p1_line = ''
    try:
        p1_raw = ser.readline()
    except:
        sys.exit ("Fout bij het lezen van poort %s. " % ser.name )
        ser.close()

    p1_raw = ''.join(chr(ch & 0x7f) for ch in p1_raw)
#    for ch in p1_raw:
       # print(chr(ch & 0x7f))
#        print( chr(ord(ch) & 0x7f))
#    print(p1_raw)
    p1_str  = p1_raw #str(p1_raw ,"utf-8",errors="ignore")
    p1_line = p1_str.strip()
    print (p1_line)
    if p1_line[0:1] == "/":
        p1_telegram = True
        p1_teller   = p1_teller + 1
        f=open("/home/geoffrey/p1_temp.log", "w")
    elif p1_line[0:1] == "!":
        if p1_telegram:
            p1_teller   = 0
            p1_telegram = False
            p1_log      = False
            f.write (p1_line)
            f.write ('rn')
            f.close()
            os.chmod("/home/geoffrey/p1_temp.log", stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)
    if p1_telegram:
        f.write (p1_line)
        f.write ('rn')
#Close port and show status
try:
    ser.close()
except:
    sys.exit ("Fout bij het sluiten van %s. Programma afgebroken." % ser.name )

Answer 3

我猜这与数据的一些解码有关。使用textIOWrapper解码对我来说很好。希望你能就我对这个案子的看法做点什么:

为了使p1协议的读出尽可能简单，我建议使用前面提到的TextIOWrapper，这样您仍然可以使用readline方法读取串行端口。"!"总是结束P1电报，因此可以用来检测消息的结束，而不是使用计数器。当收到完整的电报时，就可以处理电报了。例子:

import io
import serial
serialport = serial.Serial(  # Configure Serial communication port
                            port     = "/dev/ttyUSB0"
                            baudrate = 9600,
                            timeout  = 11,
                            bytesize = serial.SEVENBITS,
                            parity   = serial.PARITY_EVEN,
                            stopbits = serial.STOPBITS_ONE )
p1port = io.TextIOWrapper(io.BufferedReader(serialport, buffer_size=1), newline='n', encoding='ascii')
P1Message = []
while True:
    try:
         rawline = p1port.readline()
    except UnicodeDecodeError:
         print "Encode error on readline"
    if '!' in rawline:
        # Process your P1Message here
        P1Message = [] # Clear message, wait for new one
    else:
        P1Message.append(rawline)

祝你好运!

Answer 4

在代码中，将字节大小更改为EIGHTBITS，奇偶校验更改为PARITY_NONE。这些匹配cu正在使用的(也是PySerial的默认值)。

Answer 5

多亏了Geoffrey，我终于弄清楚了如何设置我的c# SerialPort。

private static SerialPort CreateP1SerialPort(string name)
{
    return new SerialPort
    {
        BaudRate = 115200,
        DataBits = 8,
        Handshake = Handshake.XOnXOff,
        Parity = Parity.None,
        PortName = name,
        RtsEnable = false,
        StopBits = StopBits.One,
        ReadTimeout = 10 * 1000,
        WriteTimeout = 1000
    };
}

简单的例子:

public static void Main()
{
   // this will help you find your com port name
   var portNames = SerialPort.GetPortNames().OrderBy(x => x).ToArray();
   // Create a new SerialPort object with default settings.
   var serialPort = CreateP1SerialPort("COM7");
   serialPort.Open(); 
   while (true)
   {
       var line = serialPort.ReadExisting();
       if (string.IsNullOrEmpty(line))
       {
           Thread.Sleep(10000); // one message every 10 seconds
       } else 
           Console.WriteLine(line);
    }
}