Question

我正在使用python的串行库进行uart通信。通信是在fpga和python 3之间进行的。我正在从fpga到在Windows 10上运行的python发送常量值，即104 108 112 115 120作为16位（LSB字节为0）。但是，有时python正在读取数据如104000、108000、112000、115000和120000。看起来python读取了属于下一个提交数据的一个字节并将其组合在一起。因此，该值是错误的。有人可以帮我找到问题吗？我已经从fpga端检查了每个数据，并且工作正常。代码如下：

import random
from itertools import count
import pandas as pd
import matplotlib.pyplot as plt
from matplotlib.figure import Figure
from matplotlib.animation import FuncAnimation
#from tkinter import *
import serial
import time

plt.style.use('fivethirtyeight')
fig = plt.figure()

ser=serial.Serial()
ser.port = 'COM4'
ser.baudrate = 57600
ser.bytesize = serial.EIGHTBITS
ser.parity = serial.PARITY_NONE
ser.stopbits = serial.STOPBITS_ONE
ser.timeout = 1
ser.open()

#root=Tk()
a_vals = []
b_vals = []
c_vals = []
q_vals = []
d_vals = []
x_vals = []

index = count()

def animate(i):

 package = bytearray()
 package.append(0x7F)
 package.append(0x7F)
 send_data = ser.write(package)
 Ia_low1 = ser.read(1)
 Ia_high1 = ser.read(1)
 Ib_low1 = ser.read(1)
 Ib_high1 = ser.read(1)
 Ic_low1 = ser.read(1)
 Ic_high1 = ser.read(1)
 Iq_low1 = ser.read(1)
 Iq_high1 = ser.read(1)
 Id_low1 = ser.read(1)
 Id_high1 = ser.read(1)

 Ia_low = ord(Ia_low1)
 Ia_high = ord(Ia_high1)
 Ib_low = ord(Ib_low1)
 Ib_high = ord(Ib_high1)
 Ic_low = ord(Ic_low1)
 Ic_high = ord(Ic_high1)
 Iq_low = ord(Iq_low1)
 Iq_high = ord(Iq_high1)
 Id_low = ord(Id_low1)
 Id_high = ord(Id_high1)
 Ia = Ia_high*1000 + Ia_low
 Ib = Ib_high*1000 + Ib_low
 Ic = Ic_high*1000 + Ic_low
 Iq = Iq_high*1000 + Iq_low
 Id = Id_high*1000 + Id_low
 time.sleep (0.1)

 a_vals.append(Ia)
 b_vals.append(Ib)
 c_vals.append(Ic)
 q_vals.append(Iq)
 d_vals.append(Id)
 x_vals.append(random.randint(0, 100))

 print ("Ia =", Ia)
 print ("Ib =", Ib)
 print ("Ic =", Ic)

 ax1 = plt.subplot(121)
 ax1.cla()
 ax1.plot(x_vals, a_vals, label='Ia')
 ax1.plot(x_vals, b_vals, label='Ib')
 ax1.plot(x_vals, c_vals, label='Ic')
 ax1.set_title('Ia, Ib, Ic illustration window')
 ax1.set_xlabel('sample')
 ax1.set_ylabel('current')
 ax1.legend()

 ax2 = plt.subplot(122)
 ax2.cla()
 ax2.plot(x_vals, q_vals, label='Iq')
 ax2.plot(x_vals, d_vals, label='Id')
 ax2.set_title('Iq, Id illustration window')
 ax2.set_xlabel('sample')
 ax2.set_ylabel('current')
 ax2.legend()

ani = FuncAnimation(fig, animate, interval = 200)


plt.tight_layout()
plt.show()

在python中的uart通讯中读取错误

0 个答案: