使用 python 和 tkinter 实时绘制串行数据

Question

我一直在努力寻找一种方法来使用 Python GUI 绘制来自 arduino 的传入数据。我能够使用 Matplotlib 动画函数来读取 6 个不同的变量并在一个子图上绘制 4 个 2 在另一个子图上绘制 2 个。这样做的速度足够快，可以实时绘制图形（每秒 20 个样本）。

我现在需要修改系统以同时读取 12 个不同的变量，其中 8 个被绘制成图表。 4 在一个子图上以每秒 20 个样本的相同速率在另一个子图上 4。我无法让它工作，并尝试了一些不同的事情并进行了大量研究，但似乎无法用我对 python 的有限知识弄清楚如何做到这一点。我对多处理或多线程不是很熟悉，但它们似乎是人们能够加快绘图过程的方式。我知道 matplotlib 动画函数本身是线程化的，所以我不确定线程​​化对此有多大帮助，或者是否有办法在一个线程中读取并在另一个线程中更新图形。我正在以 arduino 支持 250000 的最高波特率运行。我还能够找到一个例子，有人能够在这篇文章中获得非常高速的绘图，但无法修改以供我使用：@987654321 @

数据是这样从 arduino 接收的：

integer.integer.integer|integer.integer.integer|integer.integer.integer|integer.integer.integer

管道代表一个新的执行器（我发送的每个变量来自哪里）

我对 python 还很陌生，很抱歉，如果这不是 pythonic，但这里有两个例子： 这是一个使用动画功能的 gui：

import Tkinter
import serial
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
from matplotlib.figure import Figure
from matplotlib import pyplot as plt
import matplotlib.animation as animation
from collections import deque
import random

class App:
    def __init__(self, master):

        self.arduinoData = serial.Serial('com5', 250000)#115200)

        frame = Tkinter.Frame(master)

        self.running = False
        self.ani = None

        self.start = Tkinter.LabelFrame(frame, text="Start", borderwidth=10, relief=Tkinter.GROOVE, padx=10, pady=10)
        self.start.grid(row=0, column=0, padx=20, pady=20)

        self.run = Tkinter.Button(self.start, text="RUN", bd=10, height=5, width=10, command=self.getData)
        self.run.grid(row=0, column=0, padx=5, pady=5)

        self.stop_frame = Tkinter.LabelFrame(frame, text="STOP", borderwidth=10, relief=Tkinter.GROOVE, padx=10, pady=10 )
        self.stop_frame.grid(row=0, column=1, padx=20, pady=20)

        self.stop = Tkinter.Button(self.stop_frame, text="STOP", bd=10, height=5, width=10, command=self.stopTest)
        self.stop.grid(row=0, column=0, padx=5, pady=5)

        self.fig = plt.Figure()
        self.ax1 = self.fig.add_subplot(211)
        self.line0, = self.ax1.plot([], [], lw=2)
        self.line1, = self.ax1.plot([], [], lw=2)
        self.line2, = self.ax1.plot([], [], lw=2)
        self.line3, = self.ax1.plot([], [], lw=2)
        self.ax2 = self.fig.add_subplot(212)
        self.line4, = self.ax2.plot([], [], lw=2)
        self.line5, = self.ax2.plot([], [], lw=2)
        self.line6, = self.ax2.plot([], [], lw=2)
        self.line7, = self.ax2.plot([], [], lw=2)
        self.canvas = FigureCanvasTkAgg(self.fig,master=master)
        self.canvas.show()
        self.canvas.get_tk_widget().grid(row=0, column=4, padx=20, pady=20)
        frame.grid(row=0, column=0, padx=20, pady=20)

    def getData(self):
        if self.ani is None:
            self.k = 0
            self.arduinoData.flushInput()
            self.arduinoData.write("<L>")
            return self.start()
        else:
            self.arduinoData.write("<L>")
            self.arduinoData.flushInput()
            self.ani.event_source.start()
        self.running = not self.running

    def stopTest(self):
        self.arduinoData.write("<H>")
        if self.running:
            self.ani.event_source.stop()
        self.running = not self.running

    def resetTest(self):
        self.k = 0
        self.xdata = []
        self.pressure1 = []
        self.displacement1 = []
        self.cycle1 = []
        self.pressure2 = []
        self.displacement2 = []
        self.cycle2 = []
        self.pressure3 = []
        self.displacement3 = []
        self.cycle3 = []
        self.pressure4 = []
        self.displacement4 = []
        self.cycle4 = []
        self.line1.set_data(self.xdata, self.ydata1)
        self.line2.set_data(self.xdata, self.ydata2)
        self.ax1.set_ylim(0,1)
        self.ax1.set_xlim(0,1)
        self.ax2.set_ylim(0,1)
        self.ax2.set_xlim(0,1)

    def start(self):
        self.xdata = []
        self.pressure1 = []
        self.displacement1 = []
        self.cycle1 = []
        self.pressure2 = []
        self.displacement2 = []
        self.cycle2 = []
        self.pressure3 = []
        self.displacement3 = []
        self.cycle3 = []
        self.pressure4 = []
        self.displacement4 = []
        self.cycle4 = []
        self.k = 0
        self.arduinoData.flushInput()
        self.ani = animation.FuncAnimation(
            self.fig,
            self.update_graph,
            interval=1,
            repeat=True)
        self.arduinoData.write("<L>")
        self.running = True
        self.ani._start()

    def update_graph(self, i):
        self.xdata.append(self.k)
        while (self.arduinoData.inWaiting()==0):
            pass
        x = self.arduinoData.readline()
        strip_data = x.strip()
        split_data = x.split("|")
        actuator1 = split_data[0].split(".")
        actuator2 = split_data[1].split(".")
        actuator3 = split_data[2].split(".")
        actuator4 = split_data[3].split(".")
        self.pressure1.append(int(actuator1[0]))
        self.displacement1.append(int(actuator1[1]))
        self.cycle1 = int(actuator1[2])
        self.pressure2.append(int(actuator2[0]))
        self.displacement2.append(int(actuator2[1]))
        self.cycle2 = int(actuator2[2])
        self.pressure3.append(int(actuator3[0]))
        self.displacement3.append(int(actuator3[1]))
        self.cycle3 = int(actuator3[2])
        self.pressure4.append(int(actuator4[0]))
        self.displacement4.append(int(actuator4[1]))
        self.cycle4 = int(actuator4[2])
        self.line0.set_data(self.xdata, self.pressure1)
        self.line1.set_data(self.xdata, self.pressure2)
        self.line2.set_data(self.xdata, self.pressure3)
        self.line3.set_data(self.xdata, self.pressure4)
        self.line4.set_data(self.xdata, self.displacement1)
        self.line5.set_data(self.xdata, self.displacement2)
        self.line6.set_data(self.xdata, self.displacement3)
        self.line7.set_data(self.xdata, self.displacement4)
        if self.k < 49:
            self.ax1.set_ylim(min(self.pressure1)-1, max(self.pressure3) + 1)
            self.ax1.set_xlim(0, self.k+1)
            self.ax2.set_ylim(min(self.displacement1)-1, max(self.displacement3) + 1)
            self.ax2.set_xlim(0, self.k+1)
        elif self.k >= 49:
            self.ax1.set_ylim(min(self.pressure1[self.k-49:self.k])-1, max(self.pressure3[self.k-49:self.k]) + 1)
            self.ax1.set_xlim(self.xdata[self.k-49], self.xdata[self.k-1])
            self.ax2.set_ylim(min(self.displacement1[self.k-49:self.k])-1, max(self.displacement3[self.k-49:self.k]) + 1)
            self.ax2.set_xlim(self.xdata[self.k-49], self.xdata[self.k-1])
        self.k += 1




root = Tkinter.Tk()
app = App(root)
root.mainloop()

这是一个打印到监视器的 gui：

import Tkinter
import serial
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
from matplotlib.figure import Figure
from matplotlib import pyplot as plt
import matplotlib.animation as animation
import time

class App:
    def __init__(self, master):

        self.arduinoData = serial.Serial('com5', 250000, timeout=0)

        frame = Tkinter.Frame(master)

        self.go = 0

        self.start = Tkinter.LabelFrame(frame, text="Start", borderwidth=10, relief=Tkinter.GROOVE, padx=10, pady=10)
        self.start.grid(row=0, column=0, padx=20, pady=20)

        self.run = Tkinter.Button(self.start, text="RUN", bd=10, height=5, width=10, command=self.getData)
        self.run.grid(row=0, column=0, padx=5, pady=5)

        self.stop_frame = Tkinter.LabelFrame(frame, text="STOP", borderwidth=10, relief=Tkinter.GROOVE, padx=10, pady=10 )
        self.stop_frame.grid(row=0, column=1, padx=20, pady=20)

        self.stop = Tkinter.Button(self.stop_frame, text="STOP", bd=10, height=5, width=10, command=self.stopTest)
        self.stop.grid(row=0, column=0, padx=5, pady=5)

        self.fig = plt.Figure()
        self.ax1 = self.fig.add_subplot(211)
        self.line0, = self.ax1.plot([], [], lw=2)
        self.line1, = self.ax1.plot([], [], lw=2)
        self.line2, = self.ax1.plot([], [], lw=2)
        self.line3, = self.ax1.plot([], [], lw=2)
        self.ax2 = self.fig.add_subplot(212)
        self.line4, = self.ax2.plot([], [], lw=2)
        self.line5, = self.ax2.plot([], [], lw=2)
        self.line6, = self.ax2.plot([], [], lw=2)
        self.line7, = self.ax2.plot([], [], lw=2)
        self.canvas = FigureCanvasTkAgg(self.fig,master=master)
        self.canvas.show()
        self.canvas.get_tk_widget().grid(row=0, column=4, padx=20, pady=20)
        frame.grid(row=0, column=0, padx=20, pady=20)

    def getData(self):
        self.k = 0
        self.xdata = []
        self.pressure1 = []
        self.displacement1 = []
        self.cycle1 = []
        self.pressure2 = []
        self.displacement2 = []
        self.cycle2 = []
        self.pressure3 = []
        self.displacement3 = []
        self.cycle3 = []
        self.pressure4 = []
        self.displacement4 = []
        self.cycle4 = []
        self.arduinoData.flushInput()
        self.go = 1
        self.readData()

    def readData(self):
        if self.go == 1:
            self.xdata.append(self.k)
            while (self.arduinoData.inWaiting()==0):
                pass
            x = self.arduinoData.readline()
            strip_data = x.strip()
            split_data = x.split("|")
            actuator1 = split_data[0].split(".")
            actuator2 = split_data[1].split(".")
            actuator3 = split_data[2].split(".")
            actuator4 = split_data[3].split(".")
            self.pressure1.append(int(actuator1[0]))
            self.displacement1.append(int(actuator1[1]))
            self.cycle1 = int(actuator1[2])
            self.pressure2.append(int(actuator2[0]))
            self.displacement2.append(int(actuator2[1]))
            self.cycle2 = int(actuator2[2])
            self.pressure3.append(int(actuator3[0]))
            self.displacement3.append(int(actuator3[1]))
            self.cycle3 = int(actuator3[2])
            self.pressure4.append(int(actuator4[0]))
            self.displacement4.append(int(actuator4[1]))
            self.cycle4 = int(actuator4[2])
            self.printData()
            root.after(0, self.readData)


    def printData(self):
        print str(self.pressure1[self.k-1]) + " " + 
        str(self.displacement1[self.k-1]) + " " + str(self.cycle1) + " " + 
        str(self.pressure2[self.k-1]) + " " + str(self.displacement2[self.k-
        1]) + " " + str(self.cycle2) + " " + str(self.pressure3[self.k-1]) + 
        " " + str(self.displacement3[self.k-1]) + " " + str(self.cycle3) + " 
        " + str(self.pressure4[self.k-1]) + " " + 
        str(self.displacement4[self.k-1]) + " " + str(self.cycle4)

    def stopTest(self):
        self.arduinoData.write("<H>")
        self.go = 0


    def resetTest(self):
        self.k = 0
        self.xdata = []
        self.pressure1 = []
        self.displacement1 = []
        self.cycle1 = []
        self.pressure2 = []
        self.displacement2 = []
        self.cycle2 = []
        self.pressure3 = []
        self.displacement3 = []
        self.cycle3 = []
        self.pressure4 = []
        self.displacement4 = []
        self.cycle4 = []
        self.line1.set_data(self.xdata, self.ydata1)
        self.line2.set_data(self.xdata, self.ydata2)
        self.ax1.set_ylim(0,1)
        self.ax1.set_xlim(0,1)
        self.ax2.set_ylim(0,1)
        self.ax2.set_xlim(0,1)

    def start(self):
        self.xdata = []
        self.pressure1 = []
        self.displacement1 = []
        self.cycle1 = []
        self.pressure2 = []
        self.displacement2 = []
        self.cycle2 = []
        self.pressure3 = []
        self.displacement3 = []
        self.cycle3 = []
        self.pressure4 = []
        self.displacement4 = []
        self.cycle4 = []
        self.k = 0
        self.arduinoData.write("<L>")

root = Tkinter.Tk()
app = App(root)
root.mainloop()

这是一个示例 arduino 代码：

int analog0 = 0;
int analog1 = 1;
int analog2 = 2;

int sensor0;
int sensor1;
int sensor2;

String pot0;
String pot1;
String Force;

int pot0holder;
int pot1holder;
String Forceholder;

unsigned long i = 0;
String Is;

int val = 0;

boolean Sensordata = false;
int cycles;

const byte numChars = 32;
char receivedChars[numChars];
boolean newData = false;

unsigned long CurrentMillis = 0;
unsigned long PrintMillis = 0;
int PrintValMillis = 50;
unsigned long SensorMillis = 0;
int SensorValMillis = 0;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(250000);
}

void loop()
{
  CurrentMillis = millis();
  recvWithStartEndMarkers();
  commands();
  sensordata();
}

void sensordata()
{
  if (CurrentMillis - SensorMillis >= SensorValMillis)
  {
    sensor0 = analogRead(analog0);
    pot0holder = sensor0;
    sensor1 = analogRead(analog1);
    pot1holder = sensor1;
    i += 1;
    String potcolumn = String(pot0holder) + "." + String(pot1holder) + "." +  String(i) + "|" + String(int(pot0holder)+30) + "." + String(int(pot1holder)+30) + "." +  String(i) + "|" + String(int(pot0holder)+60) + "." + String(int(pot1holder)+60) + "." +  String(i) + "|" + String(int(pot0holder)+90) + "." + String(int(pot1holder)+90) + "." +  String(i);
    Serial.println(potcolumn);
    SensorMillis += SensorValMillis;
   }
}

void recvWithStartEndMarkers()
{
    static boolean recvInProgress = false; //creates variable visible to only one function with boolean
    static byte ndx = 0;
    char startMarker = '<'; //sets begin condition
    char endMarker = '>'; //sets end condition
    char rc; //sets variable type to char

    while (Serial.available() > 0 && newData == false) {
        rc = Serial.read(); //sets rc equal to serial value

        if (recvInProgress == true) {
            if (rc != endMarker) {
                receivedChars[ndx] = rc;
                ndx++;
                if (ndx >= numChars) {
                    ndx = numChars - 1;
                }
            }
            else {
                receivedChars[ndx] = '\0'; // terminate the string
                recvInProgress = false;
                ndx = 0;
                newData = true;
            }
        }
        else if (rc == startMarker) {
            recvInProgress = true;
        }
    }
}

void commands()
{
  if (newData == true)
  {
    if (receivedChars[0] == 'T')
    {
      PrintValMillis = atoi(&receivedChars[1]); //atoi -> Converting strings to integer
    }
    else if (receivedChars[0] == 'S')
    {
      cycles = atoi(&receivedChars[1]);
      i = 0;
    }
        else if (receivedChars[0] == 'L')
    {
      val = atoi(&receivedChars[1]);
      i = 0;
    }
  }
  newData = false;
}

提前感谢任何人提供的任何帮助或建议。

Answer 1

因此，您的阅读过程会占用大部分时间。我会将读数放在一个单独的任务中，并在主（绘图）过程中对数据进行评估/拆分。不幸的是，我不是 tkinter 用户，所以我在没有任何特殊 gui 框架的情况下编写了这个。但我认为您可以根据自己的需要进行调整。

看起来像这样：

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import multiprocessing as mp
import time


# global variables
fig = plt.figure(1)
# first sub-plot
ax1 = fig.add_subplot(211)
line1, = ax1.plot([], [], lw=2)
ax1.grid()
xdata1, ydata1 = [], []
# second sub-plot
ax2 = fig.add_subplot(212)
line2, = ax2.plot([], [], lw=2)
ax2.grid()
xdata2, ydata2 = [], []

# the multiprocessing queue
q = mp.Queue()

# data generator in separate process
# here would be your arduino data reader
def dataGen(output):
    for x in range(50):
        output.put((x, np.sin(x)))

# update first subplot
def update1(data):
    # update the data
    t, y = data
    xdata1.append(t)
    ydata1.append(y)
    xmin, xmax = ax1.get_xlim()
    ymin, ymax = ax1.get_ylim()

    if t >= xmax:
        ax1.set_xlim(xmin, 2*xmax)
    if y >= ymax:
        ax1.set_ylim(ymin, 2*ymax)
    if y <= ymin:
        ax1.set_ylim(2*ymin, ymax)
    line1.set_data(xdata1, ydata1)

    return line1,

# update second subplot
def update2(data):
    # update the data
    t, y = data
    xdata2.append(t)
    ydata2.append(y)
    xmin, xmax = ax2.get_xlim()
    ymin, ymax = ax2.get_ylim()

    if t >= xmax:
        ax2.set_xlim(xmin, 2*xmax)
    if y >= ymax:
        ax2.set_ylim(ymin, 2*ymax)
    if y <= ymin:
        ax2.set_ylim(2*ymin, ymax) 
    line2.set_data(xdata2, ydata2)

    return line2,

# called at each drawing frame
def run(data):
    # get data from queue, which is filled in separate process, blocks until
    # data is available
    data = q.get(block=True, timeout=.5)
    # put here your variable separation
    data1 = (2*data[0], 3*data[1])
    data2 = (data[0], data[1])
    #provide the data to the plots
    a = update1(data1)
    b = update2(data2)
    fig.canvas.draw()
    return a+b

if __name__ == "__main__":
    # count of reader processes
    n_proc = 1
    # setup workers
    pool = [mp.Process(target=dataGen, args=(q,)) for x in range(n_proc)]
    for p in pool:
        p.daemon = True
        p.start()

    # wait a few sec for the process to become alive
    time.sleep(3)

    # start your drawing
    ani = animation.FuncAnimation(fig, run, frames=60, blit=True, interval=10,
                                  repeat=False)
    plt.show()

    print('done')